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Scientific Data Documentation
National Ambulatory Medical Care Survey, 1995DSN: CC37.NAMCS95 1995 NATIONAL AMBULATORY MEDICAL CARE SURVEY DATA FILE DOCUMENTATION WARNING - DATA USE RESTRICTIONS! Read Carefully before Using The Public Health Service Act (Section 308 (d)) provides that the data collected by the National Center for Health Statistics (NCHS), Centers for Disease Control and Prevention (CDC), may be used only for the purpose of health statistical reporting and analysis. Any effort to determine the identity of any reported case is prohibited by this law. NCHS does all it can to assure that the identity of data subjects cannot be disclosed. All direct identifiers, as well as any characteristics that might lead to identification, are omitted from the dataset. Any intentional identification or disclosure of a person or establishment violates the assurances of confidentiality given to the providers of the information. Therefore, users will: 1. Use the data in this dataset for statistical reporting and analysis only. 2. Make no use of the identity of any person or establishment discovered inadvertently and advise the Director, NCHS, of any such discovery. 3. Not link this dataset with individually identifiable data from other NCHS or non-NCHS datasets. By using these data, you signify your agreement to comply with the above-stated statutorily based requirements. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * The documentation files include the following: DESCRIPT Description of the NAMCS TAPE Technical description of tape FORMAT Record format SPECLIST Physician specialty list MARGINAL Marginal data RSE Relative standard errors TERMS Definition of survey terms PRF Patient Record Form - instructions and definitions RVC Reason for Visit Classification GENCODES List of generic codes and names MEDCODES List of drug entry codes and names NDC List of drug classes CAUTION - Because the NAMCS is a sample survey, the application of weights to the sample data is REQUIRED to produce national estimates of office visits, as well as to accurately assess the sampling error of statistics based on the survey data. Please refer to the appropriate documentation files (DESCRIPT, RSE) for information on how to apply the weights and to obtain relative standard errors of national estimates. For questions, suggestions, or comments concerning NAMCS data, please contact the Ambulatory Care Statistics Branch at (301) 436-7132. These and other survey data are also available on CD-ROM and as downloadable files via the Internet, as well as in published summaries. For additional information on NCHS data products, contact the: Data Dissemination Branch, NCHS 6525 Belcrest Rd. Hyattsville, MD 20782 Tel: (301) 436-8500 E-mail: nchsquery@nch10a.em.cdc.gov Internet: http://www.cdc.gov/nchswww/nchs/home.htm I. DESCRIPTION OF THE NATIONAL AMBULATORY MEDICAL CARE SURVEY A. INTRODUCTION This file contains data collected in the 1995 National Ambulatory Medical Care Survey (NAMCS). The NAMCS is a national probability sample survey conducted by the Division of Health Care Statistics, National Center for Health Statistics (NCHS), Centers for Disease Control and Prevention (CDC). A national sample of office-based physicians provides data on patients' office visits. These data are weighted to produce national estimates that describe the utilization of ambulatory medical care services in the United States. In 1995, a total of 36,875 Patient Record forms were received from the 1,883 physicians who participated in the NAMCS. For a brief description of the survey design and data collection procedures, see below. For a more detailed description of the survey design, data collection procedures, and the estimation process, see references 1 and 2. Please note the following important points concerning analysis of NAMCS data on this micro-data file: PATIENT VISIT WEIGHT - Micro-data file users should be fully aware of the importance of the "patient visit weight" and how it must be used. Information about the patient visit weight is presented on page 13. If more information is needed the staff of the Ambulatory Care Statistics Branch can be consulted by calling (301) 436-7132 during regular working hours. RELIABILITY OF ESTIMATES - Users should also be aware of the reliability or unreliability of certain estimates, particularly the smaller estimates. The National Center for Health Statistics, which conducts many health surveys, considers an estimate to be reliable if it has a relative standard error of 30 percent or less (i.e., the standard error is no more than 30 percent of the estimate). Therefore, it is important to know the value of the lowest possible estimate in this survey that is considered reliable, so as not to present data in a journal article or paper that may be unreliable. Most data file users can obtain an adequate working knowledge of relative standard errors from the information presented in Appendix I. It should be noted that estimates based on fewer than 30 records are also considered unreliable, regardless of the magnitude of the relative standard error. If you would like more information, do not hesitate to consult the staff of the Ambulatory Care Statistics Branch. B. SCOPE OF THE SURVEY The basic sampling unit for the NAMCS is the physician-patient encounter or visit. Only visits to the offices of nonfederally employed physicians classified by the American Medical Association (AMA) or the American Osteopathic Association (AOA) as "office-based, patient care" were included in the 1995 NAMCS. Physicians in the specialties of anesthesiology, pathology, and radiology were excluded from the physician universe. Types of contacts not included in the 1995 NAMCS were those made by telephone, those made outside the physician's office (for example, house calls), visits made in hospital settings (unless the physician has a private office in a hospital and that office meets the NAMCS definition of "office"), visits made in institutional settings by patients for whom the institution has primary responsibility over time (for example, nursing homes), and visits to doctors' offices that are made for administrative purposes only (for example, to leave a specimen, pay a bill, or pick up insurance forms). C. SAMPLING FRAME AND SIZE OF SAMPLE The sampling frame for the 1995 NAMCS was composed of all physicians contained in the master files maintained by the AMA and AOA as of December 31, 1993 who met the following criteria: Office-based, as defined by the AMA and AOA; Principally engaged in patient care activities; Nonfederally employed; Not in specialties of anesthesiology, pathology, and radiology. The 1995 NAMCS sample included 3,724 physicians: 3,401 Medical Doctors and 323 Doctors of Osteopathy. Sample physicians were screened at the time of the survey to assure that they met the above-mentioned criteria. A total of 1,137 physicians did not meet all of the criteria and were ruled out of scope (ineligible) for the study. The most frequent reasons for being out of scope were that the physician was retired, deceased, or employed in teaching, research, or administration. Of the 2,587 in-scope (eligible) physicians, 73 percent participated in the study. The physician universe, sample size, and response rates by physician specialty are shown in table I. Of the participating physicians, 289 saw no patients during their assigned reporting period because of vacations, illness, or other reasons for being temporarily not in practice. --------------------------------------------------------------------------- Table I. Number of physicians in the universe, total sample, sample response categories, and response rate by physician strata: National Ambulatory Medical Care Survey, 1995 ---------------------------------------------------------------------------- Sample ---------------------------------------------------- Physician Out of In Nonres- Respon- Response strata Universe(1) Total scope scope pondents dents rate(2) ------------------------------------------------------------------------------ Number Percent ------------------------------------------------- ---- Total 375,467 3,724 1,137 2,587 704 1,883 72.8 General and family practice 57,749 328 112 216 63 153 70.8 Osteopathy 15,391 323 114 209 55 154 73.7 Internal medicine 53,760 386 128 258 75 183 70.9 Pediatrics 32,939 210 72 138 23 115 83.3 General surgery 19,843 308 100 208 48 160 76.9 Obstetrics and gynecology 28,405 179 47 132 37 95 72.0 Orthopedic surgery 16,959 322 65 257 86 171 66.5 Cardiovascular diseases 13,228 182 35 147 55 92 62.6 Dermatology 6,813 123 18 105 24 81 77.1 Urology 7,843 119 27 92 27 65 70.7 Psychiatry 26,433 321 135 186 51 135 72.6 Neurology 7,386 151 49 102 26 76 74.5 Ophthalmology 14,387 179 36 143 29 114 79.7 Otolaryngology 6,969 146 24 122 30 92 75.4 All other specialties 67,362 447 175 272 75 197 72.4 ----------------------------------------------------------------------------- (1) Data are derived from the American Medical Association and the American Osteopathic Association and represent the total number of physicians who are eligible for the NAMCS. (2) Response rate is number of respondents divided by number of in-scope physicians. D. SAMPLE DESIGN The 1995 NAMCS utilized a multistage probability design that involved probability samples of primary sampling units (PSU's), physician practices within PSU's, and patient visits within practices. The first-stage sample included 112 PSU's. PSU's are counties, groups of counties, county equivalents (such as parishes or independent cities) or towns and townships (for some PSU's in New England). The second stage consisted of a probability sample of practicing physicians selected from the master files maintained by the American Medical Association (AMA) and American Osteopathic Association (AOA). Within each PSU, all eligible physicians were stratified by fifteen groups: general and family practice, osteopathy, internal medicine, pediatrics, general surgery, obstetrics and gynecology, orthopedic surgery, cardiovascular diseases, dermatology, urology, psychiatry, neurology, ophthalmology, otolaryngology, and "all other" specialties. The final stage was the selection of patient visits within the annual practices of sample physicians. This involved two steps. First, the total physician sample was divided into 52 random subsamples of approximately equal size, and each subsample was randomly assigned to 1 of the 52 weeks in the survey year. Second, a systematic random sample of visits was selected by the physician during the assigned week. The sampling rate varied for this final step from a 100-percent sample for very small practices to a 20-percent sample for very large practices as determined in a presurvey interview. The method by which the sampling rate was determined is described in reference 3. E. POPULATION FIGURES The base population used in computing annual visit rates is presented in table II. These figures are based on provisional estimates for the civilian noninstitutionalized population as of July 1, 1995, provided by the U.S. Bureau of the Census. The population estimates are presented here solely for the purpose of providing denominators for rate computation and should not be considered official population estimates. ----------------------------------------------------------------------------- Table 1. U.S. population estimates used in computing annual visit rates for the National Ambulatory Medical Care Survey by age, race, sex, and geographic region: July 1, 1995 ----------------------------------------------------------------------------- Age groups Race and Under 5 5-14 15-24 25-34 35-44 sex years years years years years ----------------------------------------------------------------------------- All races 20,262,005 39,225,450 36,137,770 40,788,111 42,285,466 Male 10,366,860 20,073,331 18,125,031 20,062,644 20,805,043 Female 9,895,145 19,152,119 18,012,739 20,725,467 21,480,423 White 15,851,066 30,914,080 28,803,500 33,351,013 35,218,157 Male 8,128,696 15,859,174 14,569,518 16,646,356 17,560,607 Female 7,722,370 15,054,906 14,233,982 16,704,657 17,657,550 Black 3,330,641 6,292,890 5,459,213 5,324,181 5,167,944 Male 1,687,058 3,187,211 2,599,394 2,380,038 2,354,786 Female 1,643,583 3,105,679 2,859,819 2,944,143 2,813,158 Other 1,080,298 2,018,480 1,875,057 2,112,917 1,899,365 Male 551,106 1,026,946 956,119 1,036,250 889,650 Female 529,192 991,534 918,938 1,076,667 1,009,715 ----------------------------------------------------------------------------- Region Total Northeast 51,449,609 Midwest 62,239,885 South 92,390,708 West 55,822,722 ----------------------------------------------------------------------------- SOURCE: Estimates for age, sex, and race are based on U.S. Bureau of the Census monthly postcensal estimates of the civilian noninstitutionalized population of the United States as of July 1, 1995. These figures are consistent with Census reports PE-10/PPL-41, Addendum 1, and have been adjusted for net underenumeration using the 1990 National Population Adjustment Matrix. Estimates for geographic region were provided by the Division of Health Interview Statistics, NCHS, and are also based on U.S. census estimates of the civilian noninstitutionalized population as of July 1, 1995. Due to differences in the adjustment process, aggregate regional estimates differ slightly from aggregate estimates by age, sex, and race. ----------------------------------------------------------------------------- Table 1. U.S. population estimates used in computing annual visit rates for the National Ambulatory Medical Care Survey by age, race, sex, and geographic region: July 1, 1995 - con. ----------------------------------------------------------------------------- Age groups Race and 45-54 55-64 65-74 75 years sex years years years and over All ages ----------------------------------------------------------------------------- All races 30,908,230 20,798,000 18,312,463 13,189,431 261,906,926 Male 15,072,464 9,895,375 8,174,268 4,990,336 127,565,352 Female 15,835,766 10,902,625 10,138,195 8,199,095 134,341,574 White 26,416,037 17,987,153 16,253,767 11,939,172 216,733,945 Male 13,025,670 8,652,571 7,307,692 4,532,151 106,282,435 Female 13,390,367 9,334,582 8,946,075 7,407,021 110,451,510 Black 3,239,500 2,081,328 1,570,043 1,004,919 33,470,659 Male 1,459,275 902,315 654,393 354,513 15,578,983 Female 1,780,225 1,179,013 915,650 650,406 17,891,676 Other 1,252,693 729,519 488,653 245,340 11,702,322 Male 587,519 340,489 212,183 103,672 5,703,934 Female 665,174 389,030 276,470 141,668 5,998,388 ----------------------------------------------------------------------------- F. FIELD ACTIVITIES The first contact with the sample physician was through a letter from the Director, NCHS. After the physician received the introductory letter(s), the field representative telephoned the physician to set up an appointment with him or her to discuss the survey and instruct the doctor on how to complete the forms. G. DATA COLLECTION The actual data collection for the NAMCS was carried out by the physician aided by his/her office staff when possible. Two data collection forms were employed by the physician: The Patient Log and the Patient Record. The Patient Log is used to sequentially list patients seen in the physician's office during his or her assigned reporting week. This list served as the sampling frame to indicate the visits for which data were to be recorded. A perforation between the patient's name on the Patient Log and patient visit information on the Patient Record form permitted the physician to detach and retain the listing of patients, thus assuring confidentiality. Based on the physician's estimate of the expected number of office visits, each physician was assigned a patient-sampling ratio. These ratios were designed so that about 30 Patient Record forms were completed during the assigned reporting week. Physicians expecting few visits each day recorded data for all of them, while those expecting more than a predetermined number of visits per day recorded data for every second, third, or fifth visit. These procedures minimized the data collection workload and maintained approximately equal reporting levels among sample physicians regardless of practice size. A random start was provided on the first page of the log, so that predesignated sample visits on each succeeding page of the log provided a systematic random sample of patient visits during the reporting period. H. DATA PROCESSING 1. Edits In addition to the completeness checks made by the field staff, clerical edits were performed upon receipt of the data for central processing. Detailed editing instructions were provided to manually review the patient records and to reclassify or recode ambiguous entries. Computer edits for code ranges and inconsistencies were also performed. 2. Quality Control All medical and drug coding and keying operations were subject to quality control procedures. Quality control for the medical and drug coding operation, as well as straight-key items, involved a two-way 10-percent independent verification procedure. As an additional quality control, all Patient Record forms with differences between coders or illegible entries for the reason for visit, diagnosis, cause of injury (E-code), procedures, diagnosis, and medication items were reviewed and adjudicated at NCHS. The average keying error rate for nonmedical items was 0.1 percent. For items which required medical coding, discrepancy rates ranged from 0.2 percent (cause of injury) to 2.4 percent (diagnosis). 3. Imputations Item nonresponse rates were 3 percent or less for all data items with the following exceptions: race, item 4 (8 percent), ethnicity, item 6 (10 percent), and whether the patient was seen before for this visit's principal diagnosis, item 18b (6 percent). Missing data items were imputed by randomly assigning a value from a Patient Record form with similar characteristics; imputations were based on physician specialty and broad diagnostic categories. Imputations were performed for the following variables -- date of visit, year of birth, sex, race, ethnicity, referral status, prior-visit status, provider seen, disposition of visit, and visit duration. Any data field imputed in this manner is so indicated by a code in one of columns 215-225 on the data file. I. MEDICAL CODING The Patient Record form contains several medical items requiring three separate coding systems. The three coding systems are described briefly below. Quality control for the NAMCS medical and drug coding operations involved a two-way 10 percent independent verification procedure. A dependent verification procedure was used to review and adjudicate all records with coding discrepancies. Definitions of the medical items can be found in Appendix I. 1. Patient's Complaint(s), Symptoms(s) or Other Reason(s) for this Visit: Information collected in item 9 of the Patient Record form was coded according to A Reason for Visit Classification for Ambulatory Care (RVC) (reference 4). The updated classification is available (reference 5), and the list of codes is shown in Appendix II. The classification was updated to incorporate several new codes as well changes to existing codes. The system continues to utilize a modular structure. Digits 1 through 8 precede the 3-digit RVC codes to identify the various modules as follows: Prefix Module "1" = Symptom module "2" = Disease module "3" = Diagnostic, screening, and preventive module "4" = Treatment module "5" = Injuries and adverse effects module "6" = Test results module "7" = Administrative module "8" = Uncodable entries "9" = Special code = blank Up to three reasons for visit were coded from item 9 in sequence; coding instructions for this item are contained in the Reason for Visit Classification and Coding Manual (reference 5). 2. Cause of Injury: Up to three causes of injury were coded from responses to item 10c. Causes of injury were coded using the Supplementary Classification of External Causes of Injury and Poisoning (E-codes), International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) (reference 6). In the classification, E-codes range from E800-E999, and many, but not all, codes have an additional fourth digit to provide greater specificity. For the NAMCS public use file, the 'E' has been dropped. There is an implied decimal between the third and fourth digits; inapplicable fourth digits have a dash inserted. Examples: 895- = E895 = Accident caused by controlled fire in private dwelling 9056 = E905.6 = Venomous marine animals and plants as the cause of poisoning and toxic reactions 3. Physician's Diagnoses: Diagnostic information in item 11 of the Patient Record form was coded according to the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) (reference 6). In previous years, the diagnosis codes contained prefixes and zerofills to facilitate analysis using using ACSB software systems. For 1995, the ICD-9-CM codes are not prefixed or zerofilled. For example, 38100 = 381.00 = Acute nonsuppurative otitis media, unspecified. There is an implied decimal between the third and fourth digits. For inapplicable fourth or fifth digits, a dash has been inserted. For example, 4011- = 401.1 = Essential hypertension, benign. Supplementary classification codes are no longer prefixed or zerofilled. For example, V700-= V70.0 = Routine general medical examination at a health care facility. In addition to the diagnostic codes from the ICD-9-CM the following unique codes in the diagnostic fields were developed by NAMCS staff: V9900 = noncodable diagnosis, insufficient information, illegible V9910 = left before being seen, patient walked out, not seen by doctor, left against medical advice V9920 = transferred to another facility, sent to see specialist V9970 = entry of "none," "no diagnosis," "no disease," "healthy" 00000 = blank A maximum of three diagnoses were coded in sequence. Coding instructions concerning diagnoses are contained in the NAMCS Coding Requirements Manual, volume 1 (reference 7). 4. Ambulatory Surgical Procedures, Diagnostic/Screening Services: Data from item 13 (ambulatory surgical procedures) as well as any open-ended responses to item 14 (diagnostic/screening services) of the Patient Record form were coded according to the International Classification of Diseases (ICD-9-CM) using the procedure codes in Volume III. Up to 2 surgical procedures and up to 5 open-ended responses ("Other - specify") could be coded for each visit. Codes have an implied decimal between the second and third position and do not use prefixes or zerofills. Codes without an applicable 4th digit have a dash inserted. In processing survey data, it was noticed that procedures reported by one respondent in item 13 might have been reported by another respondent in item 14. For this reason, we recommend that any analysis of procedures take into account all of the possible fields (total of 7) where procedures could have been reported. 5. Medications/Injections: The NAMCS drug data collected in item 16 have been classified and coded according to a unique classification scheme developed at NCHS (reference 8). A list of drug codes is included in Appendix III. The 1995 Patient Record form allows for the recording of up to six drugs. In addition to drugs codes by entry name (the entry made on the Patient Record form by the physician or his/her staff), this file contains the following drug information: a. Generic name code: A unique, 5-digit code assigned to each official generic name assigned to every drug entity by the United States Pharmacopeia or other responsible authority. b. Prescription status code: A code designed to identify the legal status (prescription or nonprescription) of the drug entry. c. Controlled substance status code: A code used to denote the degree of potential abuse and federal control of a drug entry. d. Composition status code: A code used to distinguish between single-ingredient and combination drugs. Note: If the user is searching for single ingredient (or single entity) drugs, then he or she may utilize the composition status code = "1" in conjunction with the "generic name code" field. A single ingredient drug will have one generic code in the "generic name code" field, and blanks in the five "ingredient codes" fields. If the user is searching for combination drugs, then he or she may utilize composition status code = "2" in conjunction with the "ingredient codes" fields. But for 1995, combination products are also identified by the new codes 51380 or 51381 (see below) in the "generic name code" field. These codes indicate that the drug is a combination product and that ingredients are listed as generic codes in the "ingredient codes" fields. Therefore, users may search for combination products using either the generic name code or the composition status code. e. Ingredient codes: Codes used to identify the active generic ingredients of combination drugs. A maximum of 5 ingredients can be identified for each combination drug. f. Drug class code: A 4-digit code used to identify the primary class to which the drug entry may belong. These are based on the standard drug classifications used in the National Drug Code Directory, 1995 edition (reference 9). The first two digits represent the major drug classes and can be used alone or in conjunction with the additional digits for greater specificity within the major classes. A listing of the drug classes is shown in Appendix III. The medical classification system of drugs by entry name (Appendix III) utilizes a five-digit coding scheme which is updated regularly to include new products. It includes the following special codes: 90000 = blank 99980 = unknown entry, other 99999 = illegible entry The classification of drugs by generic name (Appendix III) also utilizes a five-digit coding scheme, with the following special codes: 50000 = generic name undetermined 51380 = combination product (multi-vitamin/multi-mineral) 51381 = fixed combination For users who are interested in analyzing drug data only (apart from visit data), you will need to isolate those records with drugs, or drug mentions, and create a separate datafile of drug mentions. Each Patient Record form can have anywhere from one to six drug mentions recorded, so whatever file is created will need to include all of them. This documentation contains marginal data on drug mentions and approximate relative standard errors. Should the data user need additional assistance in analyzing data on drug mentions the staff of the Ambulatory Care Statistics Branch is available by calling (301) 436-7132. J. ESTIMATION PROCEDURES Statistics produced from the 1995 National Ambulatory Medical Care Survey were derived by a multistage estimation procedure. The procedure produces essentially unbiased national estimates and has basically four components: 1) inflation by reciprocals of the probabilities of selection; 2) adjustment for nonresponse, 3) a ratio adjustment to fixed totals; and 4) weight smoothing. Each of these components is described below. 1. Inflation of Reciprocals by Sampling Probabilities Since the survey utilized a three-stage sample design, there were three probabilities: a) the probability of selecting the PSU; b) the probability of selecting a physician within the PSU; and c) the probability of selecting a patient visit within the physician's practice. The last probability was defined to be the exact number of office visits during the physician's specified reporting week divided by the number of Patient Record forms completed. All weekly estimates were inflated by a factor of 52 to derive annual estimates. 2. Adjustment for Nonresponse Estimates from the NAMCS data were adjusted to account for sample physicians who did not participate in the study. This was done in such a manner as to minimize the impact of nonresponse on final estimates by imputing to nonresponding physicians the practice characteristics of similar responding physicians. For this purpose, similar physicians were judged to be physicians having the same specialty designation and practicing in the same PSU. 3. Ratio Adjustment A postratio adjustment was made within each of the fifteen physician specialty groups. The ratio adjustment is a multiplication factor which had as its numerator the number of physicians in the universe in each physician specialty group and as its denominator the estimated number of physicians in that particular specialty group. The numerator was based on figures obtained from the AMA-AOA master files, and the denominator was based on data from the sample. 4. Weight Smoothing Each year there are a few sample physicians whose final visit weights are large relative to those for the rest of the sample. There is a concern that those few may adversely affect the ability of the resulting statistics to reflect the universe, especially if the sampled patient visits to some of those few physicians should be unusual relative to the universe. Extremes in final weights also increase the resulting variances. Extreme weights can be truncated, but this leads to an understatement of the total visit count. The technique of weight smoothing is used instead, because it preserves the total estimated visit count within each specialty by shifting the "excess" from visits with the largest weights to visits with smaller weights. For 1995, excessively large visits weights were truncated, and a ratio adjustment was performed. The ratio adjustment is a multiplication factor that uses as its numerator the total visit count in each physician specialty group before the largest weights are truncated, and, as its denominator, the total visit count in the same specialty group after the largest weights are truncated. The ratio adjustment was made within each of the fifteen physician specialty groups and yields the same estimated total visit count as the unsmoothed weights. K. SAMPLING ERRORS Procedures for calculating sampling errors as well as estimates of standard errors of statistics derived from the NAMCS are described in the technical notes of references 2 and 10, as well as in Appendix I of this document. L. PATIENT VISIT WEIGHT The "patient visit weight" is a vital component in the process of producing national estimates from sample data, and its use should be clearly understood by all micro-data file users. The statistics contained on the micro-data file reflect data concerning only a sample of patient visits, not a complete count of all the visits that occurred in the United States. Each record on the data file represents one visit in the sample of 36,875 visits. In order to obtain national estimates from the sample, each record is assigned an inflation factor called the "patient visit weight." By aggregating the "patient visit weights" on the 36,875 sample records for 1995, the user can obtain the estimated total of 697,082,010 office visits made in the United States. Marginal tables which are included in the documentation files contain data on numbers of records for selected variables as well as the corresponding national estimated number of visits and drug mentions obtained by aggregating the "patient visit weights" on those records. M. PHYSICIAN CODE and PATIENT CODE The purpose of these codes is to allow for greater analytical depth by permitting the user to link individual Patient Record forms on the public use file with individual physicians' practices. This linkage will This linkage will enable users to conduct more comprehensive analysis without violating the confidentiality of patients or physicians. To uniquely identify a record, both the physician code and the patient code must be used. Patient codes are merely a sequential numbering of the visits recorded by the physician (from '001' to '159') and alone will not uniquely identify visit records. In order to do so, both the unique 4-digit physician code and the 3-digit patient code must be used. The patient visit weight should never be applied directly to the patient and physician codes. REFERENCES 1. Tenney JB, White KL, Williamson JW. National Ambulatory Medical Care Survey: Background and Methodology. National Center for Health Statistics. Vital and Health Stat 2(61). 1974. 2. Schappert SM. National Ambulatory Medical Care Survey, 1991 Summary. National Center for Health Statistics. Vital Health Stat 13(116). 1994. 3. Induction Interview Form. National Ambulatory Medical Care Survey. Bureau of the Census. OMB NO. 0920-0234. 4. Schneider D, Appleton L, McLemore T. A Reason for Visit Classification for Ambulatory Care. National Center for Health Statistics. Vital and Health Stat 2(78). 1979. 5. Instruction Manual: Reason for Visit Classification and Coding Manual, 1994. National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey. Hyattsville, Maryland: National Center for Health Statistics. 1995. 6. Public Health Service and Health Care Financing Administration. International Classification of Diseases, 9th Revision, Clinical Modification. Washington: Public Health Service. 1980. 7. National Ambulatory Medical Care Survey: Coding Requirements, Volume 1 (updated annually). Ambulatory Care Statistics Branch, National Center for Health Statistics. 8. Koch H, Campbell W. The Collection and Processing of Drug Information. National Ambulatory Medical Care Survey, 1980. National Center for Health Statistics. Vital and Health Stat 2(90). 1982. 9. Food and Drug Administration. National Drug Code Directory, 1995 edition. Washington: Public Health Service. 1995. 10. Woodwell, DA. National Ambulatory Medical Care Survey, 1995 summary. Advance data from vital and health statistics; no. 286. Hyattsville, Maryland. National Center for Health Statistics. 1997. II. TECHNICAL DESCRIPTION OF TAPE CARTRIDGE (3480) REEL Data set name.......................CC37.NAMCS95 same Label...............................IBM standard label same Number of cartridges/reels..........1 same Number of recording tracks..........not applicable 9 Density (bpi).......................38,000 1600 OR 6250 Language............................EBCDIC same Parity..............................ODD same Record length.......................454 same Blocksize...........................27,694 same Number of records...................36,875 same Computer compatibility..............IBM 9021-640 same III. RECORD FORMAT Number of records = 36,875 This section consists of a detailed breakdown of each data file record, providing a brief description of each item of data included. The data are arranged sequentially according to their physical location on the file. Unless otherwise stated in the "item description" column, the data are derived from the Patient Record form. The American Medical Association (AMA), the American Osteopathic Association (AOA), and the induction interview (see "Description of the NAMCS") are alternate sources of data, while the computer generates other items by recoding selected data items. ITEM FIELD FILE NO. LENGTH LOCATION ITEM DESCRIPTION AND CODES ----------------------------------------------------------------------------- 1 6 1-6 DATE OF VISIT 1.1 2 1-2 MONTH OF VISIT 01-12: January-December 1.2 2 3-4 DAY OF VISIT 01-31 1.3 2 5-6 YEAR OF VISIT Last 2 digits of year (95) 2 3 7-9 PATIENT AGE (IN YEARS; DERIVED FROM DATE OF BIRTH) 000-115 3 1 10 SEX 1 = Female 2 = Male 4 1 11 RACE 1 = White 2 = Black 3 = Asian/Pacific Islander 4 = American Indian/Eskimo/Aleut 5 1 12 ETHNICITY 1 = Hispanic Origin 2 = Not Hispanic 6 1 13 DOES PATIENT SMOKE CIGARETTES? 1 = Yes 2 = No 3 = Unknown/Blank ITEM FIELD FILE NO. LENGTH LOCATION ITEM DESCRIPTION AND CODES ----------------------------------------------------------------------------- EXPECTED SOURCE(S) OF PAYMENT FOR VISIT 7 1 14 PART A) TYPE OF PAYMENT 0 = Type of payment blank and no source of insurance listed 1 = Preferred Provider Option 2 = Insured, fee-for-service 3 = HMO/Other prepaid 4 = Self-pay 5 = No charge 6 = Other 7 = Type of payment unspecified but source of insurance was checked in Part B 8 7 15-21 PART B) EXPECTED SOURCES OF INSURANCE (1 = Yes, 0 = No) 8.1 1 15 Blue Cross/Blue Shield 8.2 1 16 Other private insurance 8.3 1 17 Medicare 8.4 1 18 Medicaid 8.5 1 19 Worker's Compensation 8.6 1 20 Other insurance 8.7 1 21 Unknown 9 15 22-36 PATIENT'S REASON(S) FOR VISIT (See page 9 in "Description of the NAMCS" and RVC Coding List.) 9.1 5 22-26 REASON #1 10050-89990 = 1005.0-8999.0 90000 = Blank 9.2 5 27-31 REASON #2 10050-89990 = 1005.0-8999.0 90000 = Blank 9.3 5 32-36 REASON #3 10050-89990 = 1005.0-8999.0 90000 = Blank 10 1 37 IS THIS VISIT INJURY RELATED? 1 = Yes 2 = No ITEM FIELD FILE NO. LENGTH LOCATION ITEM DESCRIPTION AND CODES ----------------------------------------------------------------------------- 11 1 38 PLACE OF OCCURRENCE OF INJURY 0 = Not applicable (not an injury visit) 1 = Home 2 = School 3 = Sports/athletics area 4 = Street/highway 5 = Other 6 = Place of injury unknown 0 = Not Applicable 12 1 39 IS INJURY WORK RELATED? 0 = Not applicable (not an injury visit) 1 = Yes 2 = No 3 = Unknown 13 12 40-51 CAUSE OF INJURY (ICD-9-CM E-Codes; See page 10 in "Description of the NAMCS.") 13.1 4 40-43 CAUSE #1 There is an implied decimal between the third and fourth digits; for inapplicable fourth digits, a dash is inserted. A prefix 'E' is implied. 8000-999[-] = E800.0-E999 0000 = Not applicable/blank 13.2 4 44-47 CAUSE #2 There is an implied decimal between the third and fourth digits; for inapplicable fourth digits, a dash is inserted. A prefix 'E' is implied. 8000-999[-] = E800.0-E999 0000 = Not applicable/blank 13.3 4 48-51 CAUSE #3 There is an implied decimal between the third and fourth digits; for inapplicable fourth digits, a dash is inserted. A prefix 'E' is implied. 8000-999[-] = E800.0-E999 0000 = Not applicable/blank ITEM FIELD FILE NO. LENGTH LOCATION ITEM DESCRIPTION AND CODES ----------------------------------------------------------------------------- 14 15 52-66 PHYSICIAN'S DIAGNOSIS (See page 10 in "Description of the NAMCS.") 14.1 5 52-56 DIAGNOSIS #1 (ICD-9-CM codes) There is an implied decimal between the third and fourth digits; for inapplicable fourth or fifth digits, a dash is inserted. 0010[-] - V829[-] = 001.0[0]-V82.9[0] V9900 = Noncodable, insufficient information for coding, illegible V9910 = Left before being seen, patient walked out, not seen by doctor, left against medical advice V9920 = Transferred to another facility, sent to see specialist V9970 = Entry of "none," "no diagnosis," "no disease," or "healthy" 00000 = Blank 14.2 5 57-61 DIAGNOSIS #2 (ICD-9-CM codes) There is an implied decimal between the third and fourth digits; for inapplicable fourth or fifth digits, a dash is inserted. 0010[-] - V829[-] = 001.0[0]-V82.9[0] V9900 = Noncodable, insufficient information for coding, illegible V9910 = Left before being seen, patient walked out, not seen by doctor, left against medical advice V9920 = Transferred to another facility, sent to see specialist V9970 = Entry of "none," "no diagnosis," "no disease," or "healthy" 00000 = Blank ITEM FIELD FILE NO. LENGTH LOCATION ITEM DESCRIPTION AND CODES ----------------------------------------------------------------------------- 14.3 5 62-66 DIAGNOSIS #3 (ICD-9-CM codes) There is an implied decimal between the third and fourth digits; for inapplicable fourth or fifth digits, a dash is inserted. 0010[-] - V829[-] = 001.0[0]-V82.9[0] V9900 = Noncodable, insufficient information for coding, illegible V9910 = Left before being seen, patient walked out, not seen by doctor, left against medical advice V9920 = Transferred to another facility, sent to see specialist V9970 = Entry of "none," "no diagnosis," "no disease," or "healthy" 00000 = Blank 15 11 67-77 DOES PATIENT NOW HAVE: (1 = Yes, 0 = No) 15.1 1 67 Arthritis 15.2 1 68 Atherosclerosis 15.3 1 69 Chronic obstructive pulmomary disease 15.4 1 70 Chronic renal failure 15.5 1 71 Depression 15.6 1 72 Diabetes 15.7 1 73 HIV/AIDS 15.8 1 74 Hyperactivity/Attention deficit disorder 15.9 1 75 Hypertension 15.10 1 76 Obesity 15.11 1 77 None of the above 16 AMBULATORY SURGICAL PROCEDURES PEFORMED 16.1 1 78 Were ambulatory surgical procedures performed at this visit? 1 = Yes 2 = No NOTE: Because some survey respondents reported ambulatory surgical procedures in the open-ended response categories of the diagnostic and screening services item (and vice versa), it is recommended that any analysis of procedures take into account all of the open-ended response categories from both of these two items. ITEM FIELD FILE NO. LENGTH LOCATION ITEM DESCRIPTION AND CODES ----------------------------------------------------------------------------- 16.2 4 79-82 Ambulatory surgical procedure #1 (ICD-9-CM, Vol. 3. See pp. 11-14, "Description of the NAMCS.") A left-justified alphanumeric code with an implied decimal after the first two digits; inapplicable fourth digits have a dash inserted. 0101-9999 = 01.01-99.99 0000 = Not applicable/blank/uncodable 16.3 4 83-86 Ambulatory surgical procedure #2 (ICD-9-CM, Vol. 3. See pp. 11-14, "Description of the NAMCS.") 0101-9999 = 01.01-99.99 0000 = Not applicable/blank/uncodable 17 DIAGNOSTIC/SCREENING SERVICES 17.1 1 87 Were diagnostic/screening services ordered or provided at this visit? 1 = Yes 2 = No Part 1 - EXAMINATIONS (1=Yes, 0=No) 17.2 1 88 Breast exam 17.3 1 89 Pelvic exam 17.4 1 90 Rectal exam 17.5 1 91 Visual acuity exam 17.6 1 92 Mental status exam 17.7 1 93 Other exam 17.8 4 94-97 Other exam (ICD-9-CM, Vol. 3, Procedures.) (See item 16.2 for more information.) 0101-9999,0000 = 01.01-99.99,0000 ITEM FIELD FILE NO. LENGTH LOCATION ITEM DESCRIPTION AND CODES ----------------------------------------------------------------------------- Part 2 - TESTS (1=Yes, 0=No) 17.9 1 98 Blood Pressure 17.10 1 99 Urinalysis 17.11 1 100 TB skin test 17.12 1 101 Blood lead level 17.13 1 102 Cholesterol measure 17.14 1 103 PSA 17.15 1 104 HIV serology 17.16 1 105 Other blood test 17.17 1 106 Other test 17.18 4 107-110 Other test (ICD-9-CM, Vol. 3, Procedures.) 0101-9999,0000 = 01.01-99.99,0000 (See item 16.2 for more information.) Part 3 - IMAGING (1=Yes, 0=No) 17.19 1 111 X-ray 17.20 1 112 CAT scan 17.21 1 113 Magnetic resonance imaging (MRI) 17.22 1 114 Ultrasound 17.23 1 115 Other imaging 17.24 4 116-119 Other imaging (ICD-9-CM,Vol. 3,Procedures.) (See item 16.2 for more information.) 0101-9999,0000 = 01.01-99.99,0000 17.25 1 120 Other diagnostic/screening service? 1 = Yes, 0 = No 17.26 4 121-124 Other service #1 (ICD-9-CM, Vol. 3, Procedures.) (See item 16.2 for more information.) 0101-9999,0000 = 01.01-99.99,0000 17.27 4 125-128 Other service #2 (ICD-9-CM, Vol. 3, Procedures.) (See item 16.2 for more information.) 0101-9999,0000 = 01.01-99.99,0000 ITEM FIELD FILE NO. LENGTH LOCATION ITEM DESCRIPTION AND CODES ----------------------------------------------------------------------------- 17.28 2 129-130 Total number of checkboxes and write-in services (0-22)* *NOTE: This figure was computed by adding up specific checkboxes (item 14, boxes 2-6, 8-15, 17-20) as well as open-ended responses to item 14, boxes 7, 16, 21, and 22 (box 22 allows for the recording of up to 2 services.) If there was a service reported that was codable to the ICD-9-CM, it was included in the count of total services. However, many respondents indicated on the Patient Record forms that "other" services were ordered or performed by checking off boxes 7, 16, 21, and/or 22, but did not list the actual procedure. In those cases, the procedure was coded as '0000' and does not appear in the count of total services ordered or performed. This means that this value will be an undercount in some cases. If necessary, the data user can compute his or her own count by using only the checkboxes (2-22) along with the field for second procedure code (125-128) which does not have its own checkbox. 18 THERAPEUTIC AND PREVENTIVE SERVICES 18.1 1 131 Were therapeutic or preventive services ordered or provided? 1 = Yes 2 = No Part 1 - COUNSELING/EDUCATION (1=Yes,0=No) 18.2 1 132 Diet 18.3 1 133 Exercise 18.4 1 134 Weight reduction 18.5 1 135 Cholesterol reduction 18.6 1 136 HIV transmission 18.7 1 137 Injury prevention 18.8 1 138 Tobacco use/exposure 18.9 1 139 Growth/development 18.10 1 140 Mental health 18.11 1 141 Other counseling Part 2 - OTHER THERAPY (1=Yes, 0=No) 18.12 1 142 Psychotherapy 18.13 1 143 Corrective lenses 18.14 1 144 Physiotherapy 18.15 1 145 Other counseling ITEM FIELD FILE NO. LENGTH LOCATION ITEM DESCRIPTION AND CODES ----------------------------------------------------------------------------- 19.1 1 146 WERE MEDICATIONS ORDERED OR PROVIDED AT THIS VISIT? 1 = Yes 2 = No 19.2 1 147 NUMBER OF MEDICATIONS CODED (0 TO 6) 19.3 30 148-177 MEDICATIONS (See page 12, "Description of the NAMCS" and Drug Entry code list.) 19.3a 5 148-152 MEDICATION #1 CODE 00005-95194 = 00005-95194 90000 = Blank 99980 = Unknown Entry; Other 99999 = Illegible Entry 19.3b 5 153-157 MEDICATION #2 CODE 00005-95194 = 00005-95194 90000 = Blank 99980 = Unknown Entry; Other 99999 = Illegible Entry 19.3c 5 158-162 MEDICATION #3 CODE 00005-95194 = 00005-95194 90000 = Blank 99980 = Unknown Entry; Other 99999 = Illegible Entry 19.3d 5 163-167 MEDICATION #4 CODE 00005-95194 = 00005-95194 90000 = Blank 99980 = Unknown Entry; Other 99999 = Illegible Entry 19.3e 5 168-172 MEDICATION #5 CODE 00005-95194 = 00005-95194 90000 = Blank 99980 = Unknown Entry; Other 99999 = Illegible Entry ITEM FIELD FILE NO. LENGTH LOCATION ITEM DESCRIPTION AND CODES ----------------------------------------------------------------------------- 19.3f 5 173-177 MEDICATION #6 CODE 00005-95194 = 00005-95194 90000 = Blank 99980 = Unknown Entry; Other 99999 = Illegible Entry 20 7 178-184 PROVIDERS SEEN THIS VISIT (1=Yes, 0=No) 20.1 1 178 Physician 20.2 1 179 Physician assistant 20.3 1 180 Nurse practitioner 20.4 1 181 Registered nurse 20.5 1 182 Licensed practical nurse 20.6 1 183 Medical assistant 20.7 1 184 Other provider 21.1 1 185 HAVE YOU SEEN PATIENT BEFORE? 1 = Yes 2 = No 21.2 1 186 IF YES, FOR THE DIAGNOSIS IN ITEM 11A? 0 = Not Applicable 1 = Yes 2 = No 22 1 187 WAS PATIENT REFERRED BY ANOTHER PHYSICIAN? 1 = Yes 2 = No 23 5 188-192 DISPOSITION OF THIS VISIT (1=Yes, 0=No) 23.1 1 188 No follow-up planned 23.2 1 189 Return if needed, P.R.N. 23.3 1 190 Return at specified time 23.4 1 191 Admit to hospital 23.5 1 192 Other 24 3 193-195 DURATION OF THIS VISIT (IN MINUTES) 000-240 ITEM FIELD FILE NO. LENGTH LOCATION ITEM DESCRIPTION AND CODES ----------------------------------------------------------------------------- 25 6 196-201 PATIENT VISIT WEIGHT (See page 16 in "Description of the NAMCS.") A right justified, alphanumeric integer developed by the NAMCS staff for the purpose of producing national estimates from sample data. 26 1 202 GEOGRAPHIC REGION (Based on actual location of physician's practice.) 1 = Northeast 2 = Midwest 3 = South 4 = West 27 1 203 METROPOLITAN/NON METROPOLITAN (Based on actual location in conjunction with the definition of the Bureau of the Census and the U.S. Office of Management and Budget.) 1 = SMSA (Standard Metropolitan Statistical Area) 2 = Non-SMSA 28 3 204-206 PHYSICIAN SPECIALTY COLLECTED FROM INDUCTION INTERVIEW (REFERENCE 3) (See "Physician Specialty List.") 29 1 207 TYPE OF DOCTOR 1 = M.D. - Doctor of Medicine 2 = D.0. - Doctor of Osteopathy 30.1 4 208-211 PHYSICIAN CODE - A unique 4-digit code assigned to all records from a particular physician 30.2 3 212-214 PATIENT CODE - A 3-digit number assigned to identify each individual record from a particular physician ITEM FIELD FILE NO. LENGTH LOCATION ITEM DESCRIPTION AND CODES ----------------------------------------------------------------------------- **** THE FOLLOWING FIELDS HAD DATA IMPUTED TO REPLACE BLANKS**** 31.1 1 215 Visit date (1=Imputed, 0=Not Imputed) 31.2 1 216 Birth Year 31.3 1 217 Race " 31.4 1 218 Sex " 31.5 1 219 Ethnicity " 31.6 1 220 Provider seen " 31.7 1 221 Seen patient before " 31.8 1 222 If yes, for diagnosis in 11A " 31.9 1 223 Referral " 31.10 1 244 Disposition of visit " 31.11 1 225 Duration of visit " ******************* END OF IMPUTED DATA FIELDS ******************** ITEM FIELD FIELD FILE NO. NAME LENGTH LOCATION ITEM DESCRIPTION AND CODES ----------------------------------------------------------------------------- 32 37 226-262 DRUG-RELATED INFO FOR MEDICATION #1 32.1 5 226-230 GENERIC NAME CODE (See Generic Code List.) 50001-51379, 51382-92503 = Specific Generic Code 51380 = Combination Product (multi-vitamin/multi-mineral) 51381 = Fixed Combination 50000 = Generic Name Undetermined 32.2 1 231 PRESCRIPTION STATUS CODE 1 = Prescription Drug 2 = Nonprescription Drug 3 = Undetermined 32.3 1 232 CONTROLLED SUBSTANCE STATUS CODE 1 = Schedule 1 (Research Only) 2 = Schedule II 3 = Schedule III 4 = Schedule IV 5 = Schedule V 6 = No Control 7 = Undetermined 32.4 1 233 COMPOSITION STATUS CODE 1 = Single Entity Drug 2 = Combination Drug 3 = Undetermined 32.5 4 234-237 NAT'L DRUG CODE DIRECTORY DRUG CLASS (See NDC Code List.) 0100 - 2100 = NDC Drug Class 32.6a 25 238-262 INGREDIENT CODE (Ingredients of Combination Drugs; Maximum of 5 Generic Name Codes) 32.6b 5 238-242 INGREDIENT #1 CODE 50001-92503, or 50000 32.6c 5 243-247 INGREDIENT #2 CODE 50001-92503, or 50000 ITEM FIELD FILE NO. LENGTH LOCATION ITEM DESCRIPTION AND CODES ----------------------------------------------------------------------------- 32.6d 5 248-252 INGREDIENT #3 CODE 50001-92503, or 50000 32.6e 5 253-257 INGREDIENT #4 CODE 50001-92503, or 50000 32.6f 5 258-262 INGREDIENT #5 CODE 50001-92503, or 50000 33 37 263-299 DRUG-RELATED INFO FOR MEDICATION #2 33.1 5 263-267 GENERIC NAME CODE (See Generic Code List.) 50001-51379, 51382-92503 = Specific Generic Code 51380 = Combination Product (multi-vitamin/multi-mineral) 51381 = Fixed Combination 50000 = Generic Name Undetermined 33.2 1 268 PRESCRIPTION STATUS CODE 1 = Prescription Drug 2 = Nonprescription Drug 3 = Undetermined 33.3 1 269 CONTROLLED SUBSTANCE STATUS CODE 1 = Schedule 1 (Research Only) 2 = Schedule II 3 = Schedule III 4 = Schedule IV 5 = Schedule V 6 = No Control 7 = Undetermined 33.4 1 270 COMPOSITION STATUS CODE 1 = Single Entity Drug 2 = Combination Drug 3 = Undetermined 33.5 4 271-274 NAT'L DRUG CODE DIRECTORY DRUG CLASS (See NDC Code List.) 0100 - 2100 = NDC Drug Class ITEM FIELD FIELD FILE NO. NAME LENGTH LOCATION ITEM DESCRIPTION AND CODES ----------------------------------------------------------------------------- 33.6 25 275-299 INGREDIENT CODE (Ingredients of Combination Drugs; Maximum of 5 Generic Name Codes) 33.6a 5 275-279 INGREDIENT #1 CODE 50001-92503, or 50000 33.6b 5 280-284 INGREDIENT #2 CODE 50001-92503, or 50000 33.6c 5 285-289 INGREDIENT #3 CODE 50001-92503, or 50000 33.6d 5 290-294 INGREDIENT #4 CODE 50001-92503, or 50000 33.6e 5 295-299 INGREDIENT #5 CODE 50001-92503, or 50000 34 37 300-336 DRUG-RELATED INFO FOR MEDICATION #3 34.1 5 300-304 GENERIC NAME CODE (See Generic Code List.) 50001-51379, 51382-92503 = Specific Generic Code 51380 = Combination Product (multi-vitamin/multi-mineral) 51381 = Fixed Combination 50000 = Generic Name Undetermined 34.2 1 305 PRESCRIPTION STATUS CODE 1 = Prescription Drug 2 = Nonprescription Drug 3 = Undetermined 34.3 1 306 CONTROLLED SUBSTANCE STATUS CODE 1 = Schedule 1 (Research Only) 2 = Schedule II 3 = Schedule III 4 = Schedule IV 5 = Schedule V 6 = No Control 7 = Undetermined ITEM FIELD FILE NO. LENGTH LOCATION ITEM DESCRIPTION AND CODES ----------------------------------------------------------------------------- 34.4 1 307 COMPOSITION STATUS CODE 1 = Single Entity Drug 2 = Combination Drug 3 = Undetermined 34.5 4 308-311 NAT'L DRUG CODE DIRECTORY DRUG CLASS (See NDC Code List.) 0100 - 2100 = NDC Drug Class 34.6 25 312-336 INGREDIENT CODE (Ingredients of Combination Drugs; Maximum of 5 Generic Name Codes) 34.6a 5 312-316 INGREDIENT #1 CODE 50001-92503, or 50000 34.6b 5 317-321 INGREDIENT #2 CODE 50001-92503, or 50000 34.6c 5 322-326 INGREDIENT #3 CODE 50001-92503, or 50000 34.6d 5 327-331 INGREDIENT #4 CODE 50001-92503, or 50000 34.6e 5 332-336 INGREDIENT #5 CODE 50001-92503, or 50000 35 37 337-373 DRUG-RELATED INFO FOR MEDICATION #4 35.1 5 337-341 GENERIC NAME CODE (See Generic Code List.) 50001-51379, 51382-92503 = Specific Generic Code 51380 = Combination Product (multi-vitamin/multi-mineral) 51381 = Fixed Combination 50000 = Generic Name Undetermined 35.2 1 342 PRESCRIPTION STATUS CODE 1 = Prescription Drug 2 = Nonprescription Drug 3 = Undetermined ITEM FIELD FIELD FILE NO. NAME LENGTH LOCATION ITEM DESCRIPTION AND CODES ----------------------------------------------------------------------------- 35.3 1 343 CONTROLLED SUBSTANCE STATUS CODE 1 = Schedule 1 (Research Only) 2 = Schedule II 3 = Schedule III 4 = Schedule IV 5 = Schedule V 6 = No Control 7 = Undetermined 35.4 1 344 COMPOSITION STATUS CODE 1 = Single Entity Drug 2 = Combination Drug 3 = Undetermined 35.5 4 345-348 NAT'L DRUG CODE DIRECTORY DRUG CLASS (See NDC Code List.) 0100-2100 = NDC Drug Class 35.6 25 349-373 INGREDIENT CODE (Ingredients of Combination Drugs; Maximum of 5 Generic Name Codes) 35.6a 5 349-353 INGREDIENT #1 CODE 50001-92503, or 50000 35.6b 5 354-358 INGREDIENT #2 CODE 50001-92503, or 50000 35.6c 5 359-363 INGREDIENT #3 CODE 50001-92503, or 50000 35.6d 5 364-368 INGREDIENT #4 CODE 50001-92503, or 50000 35.6e 5 369-373 INGREDIENT #5 CODE 50001-92503, or 50000 ITEM FIELD FILE NO. LENGTH LOCATION ITEM DESCRIPTION AND CODES ----------------------------------------------------------------------------- 36 37 374-410 DRUG-RELATED INFO FOR MEDICATION #5 36.1 5 374-378 GENERIC NAME CODE (See Generic Code List.) 50001-51379, 51382-92503 = Specific Generic Code 51380 = Combination Product (multi-vitamin/multi-mineral) 51381 = Fixed Combination 50000 = Generic Name Undetermined 36.2 1 379 PRESCRIPTION STATUS CODE 1 = Prescription Drug 2 = Nonprescription Drug 3 = Undetermined 36.3 1 380 CONTROLLED SUBSTANCE STATUS CODE 1 = Schedule 1 (Research Only) 2 = Schedule II 3 = Schedule III 4 = Schedule IV 5 = Schedule V 6 = No Control 7 = Undetermined 36.4 1 381 COMPOSITION STATUS CODE 1 = Single Entity Drug 2 = Combination Drug 3 = Undetermined 36.5 4 382-385 NAT'L DRUG CODE DIRECTORY DRUG CLASS (See NDC code list.) 0100-2100 = NDC Drug Class 36.6 25 386-410 INGREDIENT CODE (Ingredients of Combination Drugs; Maximum of 5 Generic Name Codes) 36.6a 5 386-390 INGREDIENT #1 CODE 50001-92503, or 50000 ITEM FIELD FILE NO. LENGTH LOCATION ITEM DESCRIPTION AND CODES ----------------------------------------------------------------------------- 36.6b 5 391-395 INGREDIENT #2 CODE 50001-92503, or 50000 36.6c 5 396-400 INGREDIENT #3 CODE 50001-92503, or 50000 36.6d 5 401-405 INGREDIENT #4 CODE 50001-92503, or 50000 36.6e 5 406-410 INGREDIENT #5 CODE 50001-92503, or 50000 37 37 411-447 DRUG-RELATED INFO FOR MEDICATION #6 37.1 5 411-415 GENERIC NAME CODE (See Generic Code List.) 50001-51379, 51382-92503 = Specific Generic Code 51380 = Combination Product (multi-vitamin/multi-mineral) 51381 = Fixed Combination 50000 = Generic Name Undetermined 37.2 1 416 PRESCRIPTION STATUS CODE 1 = Prescription Drug 2 = Nonprescription Drug 3 = Undetermined 37.3 1 417 CONTROLLED SUBSTANCE STATUS CODE 1 = Schedule 1 (Research Only) 2 = Schedule II 3 = Schedule III 4 = Schedule IV 5 = Schedule V 6 = No Control 7 = Undetermined 37.4 1 418 COMPOSITION STATUS CODE 1 = Single Entity Drug 2 = Combination Drug 3 = Undetermined ITEM FIELD FILE NO. LENGTH LOCATION ITEM DESCRIPTION AND CODES ----------------------------------------------------------------------------- 37.5 4 419-422 NAT'L DRUG CODE DIRECTORY DRUG CLASS (See NDC Code List.) 0100-2100 = NDC Drug Class 37.6 25 423-447 INGREDIENT CODE (Ingredients of Combination Drugs; Maximum of 5 Generic Name Codes) 37.6a 5 423-427 INGREDIENT #1 CODE 50001-92503, or 50000 37.6b 5 428-432 INGREDIENT #2 CODE 50001-92503, or 50000 37.6c 5 433-437 INGREDIENT #3 CODE 50001-92503, or 50000 37.6d 5 438-442 INGREDIENT #4 CODE 50001-92503, or 50000 37.6e 5 443-447 INGREDIENT #5 CODE 50001-92503, or 50000 ***THE FOLLOWING ITEM WAS ADDED TO ENABLE USERS TO CALCULATE VISIT RATES BY RACE*** 38 1 448 RACE RECODE 1 = White 2 = Black 3 = Other ITEM FIELD FILE NO. LENGTH LOCATION ITEM DESCRIPTION AND CODES ----------------------------------------------------------------------------- ***The following item was added to enable users to produce visit estimates by specialty group using the same groups shown in NAMCS reports.*** 39 2 449-450 PHYSICIAN SPECIALTY RECODE 01 = General/family practice 03 = Internal medicine 04 = Pediatrics 05 = General surgery 06 = Obstetrics and gynecology 07 = Orthopedic surgery 08 = Cardiovascular diseases 09 = Dermatology 10 = Urology 11 = Psychiatry 12 = Neurology 13 = Ophthalmology 14 = Otolaryngology 15 = Other specialties NOTE: Category "02" is reserved for doctors of osteopathy. Since doctors of osteopathy are aggregated with doctors of medicine according to their self-designated practice specialty in most NAMCS publications, this category is not applicable here. For users who wish to produce estimates for doctors of osteopathy apart from doctors of medicine, it is necessary to crosstabulate "Physician Specialty Recode" with "Type of Doctor" in position 207. ***The following item was added to enable data users to create subsets of visits by patients under 1 year of age.*** 40 3 451-453 AGE IN DAYS 000-365 = 000-365 days 999 = More than 365 days ***The following item was added to facilitate the calculation of visit rates by age.*** 41 1 454 AGE RECODE 1 = Under 15 years 2 = 15-24 years 3 = 25-44 years 4 = 45-64 years 5 = 65-74 years 6 = 75 years and over IV. PHYSICIAN SPECIALTY LIST The 1995 NAMCS survey design grouped physicians into 15 strata, or specialty groups, for sampling purposes. One stratum, doctors of osteopathy, was based on information from the American Osteopathic Association. The other groups were developed based on information from the American Medical Association (AMA). Below is a list of the AMA physician specialties comprising each of these sample strata. An asterisk beside the specialty name indicates that the specialty was added to the NAMCS for the first time in 1995. GENERAL PRACTICE FP - Family Practice FPG - Family Practice, Geriatric Medicine FSM - Sports Medicine (Family Practice) GP - General Practice INTERNAL MEDICINE IM - Internal Medicine PEDIATRICS ADL - Adolescent Medicine CCP - Critical Care Pediatrics MPD - Internal Medicine/Pediatrics* NPM - Neonatal-Perinatal Medicine PD - Pediatrics PDA - Pediatric Allergy PDC - Pediatric Cardiology PDE - Pediatric Endocrinology PDI - Pediatric Infectious Diseases* PDP - Pediatric Pulmonology PDT - Medical Toxicology* PEM - Pediatric Emergency Medicine PG - Pediatric Gastroenterology PHO - Pediatric Hematology/Oncology PN - Pediatric Nephrology PPR - Pediatric Rheumatology* PSM - Sports Medicine* GENERAL SURGERY GS - General Surgery OBSTETRICS AND GYNECOLOGY GO - Gynecological Oncology GYN - Gynecology MFM - Maternal & Fetal Medicine OBG - Obstetrics & Gynecology OBS - Obstetrics OCC - Critical Care Medicine (Obstetrics & Gynecology) REN - Reproductive Endocrinology ORTHOPEDIC SURGERY HSO - Hand Surgery (Orthopedic Surgery) OAR - Adult Reconstructive Orthopedics OFA - Foot and Ankle Orthopedics* OMO - Musculoskeletal Oncology OP - Pediatric Orthopedics ORS - Orthopedic Surgery OSM - Sports Medicine (Orthopedic Surgery) OSS - Orthopedic Surgery of the Spine OTR - Orthopedic Trauma CARDIOVASCULAR DISEASES CD - Cardiovascular Diseases DERMATOLOGY D - Dermatology UROLOGY U - Urology UP - Pediatric Urology* PSYCHIATRY ADP - Addiction Psychiatry* CHP - Child Psychiatry P- Psychiatry PYA - Psychoanalysis PYG - Geriatric Psychiatry PFP - Forensic Psychiatry* NEUROLOGY CHN - Child Neurology CN - Clinical Neurophysiology N - Neurology OPHTHALMOLOGY OPH - Ophthalmology PO - Pediatric Ophthalomology* OTOLARYNGOLOGY OTO - Otolaryngology (includes OT - Otology) PDO - Pediatric Otolaryngology* ALL OTHER A - Allergy AI - Allergy and Immunology ADM - Addiction Medicine ALI - Allergy & Immunology/Diagnostic Lab. Immunology AM - Aerospace Medicine AMI - Adolescent Medicine (Internal Medicine)* AS - Abdominal Surgery CBG - Clinical Biochemical Genetics* CCG - Clinical Cytogenetics* CCM - Critical Care Medicine CCS - Critical Care Surgery CDS - Cardiovascular Surgery CG - Clinical Genetics* CMG - Clinical Molecular Genetics* CRS - Colon and Rectal Surgery CTS - Cardiothoracic Surgery* DIA - Diabetes DDL - Dermatological Immunology/Diagnostic Lab. Immunology EM - Emergency Medicine END - Endocrinology ESM - Sports Medicine (Emergency Medicine)* ETX - Medical Toxicology (Emergency Medicine)* FPS - Facial Plastic Surgery GE - Gastroenterology GPM - General Preventive Medicine HEM - Hematology HEP - Hepatology* HNS - Head and Neck Surgery HO - Hematology/Oncology* HSP - Hand Surgery (Plastic Surgery) HSS - Hand Surgery (Surgery) ICE - Cardiac Electrophysiology ID - Infectious Diseases IG - Immunology ILI - Internal Medicine/Diagnostic Lab. Immunology IMG - Geriatric Medicine (Internal Medicine) ISM - Sports Medicine (Internal Medicine)* LM - Legal Medicine MDM - Medical Management* MG - Medical Genetics MPH - Public Health and General Preventive Medicine* NCC - Critical Care (Neurological Surgery) NEP - Nephrology NS - Neurological Surgery NSP - Pediatric Surgery (Neurology) NTR - Nutrition OM - Occupational Medicine ON - Medical Oncology PA - Clinical Pharmacology PCC - Pulmonary Critical Care Medicine* PDS - Pediatric Surgery PE - Pediatric Emergency Medicine (Emergency Medicine)* PH - Public Health and General Preventive Medicine PLI - Pediatric/Diagnostic Lab. Immunology PLM - Palliative Medicine* PM - Physical Medicine & Rehabilitation PMD - Pain Medicine* PS - Plastic Surgery PTX - Medical Toxicology (Preventive Medicine)* PUD - Pulmonary Diseases RHU - Rheumatology SCI - Spinal Cord Injury* SM - Sleep Medicine* SO - Surgical Oncology* TS - Thoracic Surgery TTS - Transplant Surgery* TRS - Traumatic Surgery UM - Undersea Medicine VS - Vascular Surgery OS - Other Specialty US - Unspecified V. MARGINAL DATA A. PATIENT VISITS ______________________________________________________________________________ PATIENT AGE TOTAL < 15 15-24 25-44 45-64 65-74 75+ ALL 36875 5023 2856 9902 9286 5311 4497 REC 697082010 131548104 56277962 181590184 159530815 90544098 77590847 VIS 100.000 18.871 8.073 26.050 22.886 12.989 11.131 PER ______________________________________________________________________________ PATIENT RACE WHITE BLACK ASIAN/PA AM INDIA TOTAL ISLANDER ESK/ALEU ALL 36875 32747 2758 1226 144 RECORDS 697082010 608384050 59678321 26718005 2301634 VISITS 100.000 87.276 8.561 3.833 0.330 PERCENT ______________________________________________________________________________ PATIENT SEX TOTAL FEMALE MALE ALL 36875 21569 15306 RECORDS 697082010 416319683 280762327 VISITS 100.000 59.723 40.277 PERCENT ______________________________________________________________________________ EXPECTED TYPE OF PAYMENT PREFERRD INSURED HMO OTHR SELF-PAY NO CHRGE OTHER TOTAL PROVIDER FEE-SRV PREPAID ALL 36875 3996 14628 7616 3846 595 474 697082010 79917494 259981754 158216018 74074395 7746342 9214195 100.000 11.465 37.296 22.697 10.626 1.111 1.322 UNSPECIFIED* NO ANSWER (PART A AND B BLANK) 5247 473 RECORDS 99367854 8563958 VISITS 14.255 1.229 PERCENT * Type of payment not specified but source of insurance reported in part B. ______________________________________________________________________________ EXPECTED SOURCE(S) OF INSURANCE BC/BS OTHER MEDICARE MEDICAID WORKERS OTHER TOTAL PRIVATE COMP ALL 36875 5659 11481 8821 3310 1210 3541 697082010 104081562 219945304 150472056 72951945 16460608 66681587 100.000 14.931 31.552 21.586 10.465 2.361 9.566 UNKNOWN 2126 RECORDS 44230441 VISITS 6.345 PERCENT ______________________________________________________________________________ PHYSICIAN SPECIALTY TOTAL GEN PRAC INT MED PEDIATRICS GEN SURG OB-GYNS ORTH SUR ALL 36875 6108 4187 2793 2475 1984 3432 697082010 180259100 105953009 88955789 19179109 52885959 40685609 100.000 25.859 15.200 12.761 2.751 7.587 5.837 CARD VAS DERMATOL UROLOGY PSYCHIAT NEUROLOGY OPHTHALM OTOLARYN 1387 1886 1064 2431 1310 2571 1934 14500856 25001600 13542986 21909625 7386925 40692641 16535091 2.080 3.587 1.943 3.143 1.060 5.838 2.372 OTHER 3313 RECORDS 69593711 VISITS 9.984 PERCENT ______________________________________________________________________________ PLACE OF OCCURRENCE OF INJURY TOTAL HOME SCHOOL SPORTS/ STREET/ OTHER UNKNOWN ATHLETICS HIGHWAY AREA ALL 36875 786 126 346 595 1115 2011 697082010 14064932 2056108 4804259 9421532 16968059 34334181 100.000 2.018 0.295 0.689 1.352 2.434 4.925 NOT APPLICABLE 31896 RECORDS 615432939 VISITS 88.287 PERCENT ______________________________________________________________________________ COUNSELING/EDUCATION NONE DIET EXERCISE WEIGHT CHOLEST HIV TRANS- TOTAL REDUCTION REDUCTIO MISSION ALL 36875 23197 4142 3527 1532 931 126 697082010 453808536 92628806 69372919 33064848 20397832 2821304 100.000 65.101 13.288 9.952 4.743 2.926 0.405 INJURY TOBACCO GROWTH/ MENTAL OTHER PSYCHO- PREVENT USE/EXPO DEVELOPM HEALTH COUNS/ED THERAPY 855 973 972 1631 2835 2002 17653150 20765253 26968259 20830045 50940308 19285933 2.532 2.979 3.869 2.988 7.308 2.767 CORRECTIVE PHYSIO- OTHER LENSES THERAPY THERAPY 447 1170 948 RECORDS 6813347 17362280 14789056 VISITS 0.977 2.491 2.122 PERCENT ______________________________________________________________________________ PROVIDERS SEEN PHYSICIAN PHYSICIAN NURSE RN LPN TOTAL ASSISTANT PRACTITIONER ALL 36875 35739 717 185 4628 3463 697082010 668883278 13319723 4711455 90973412 80383418 100.000 95.955 1.911 0.676 13.051 11.531 MEDICAL OTHER ASSISTNT PROVIDER 8098 1466 RECORDS 162083146 24672884 VISITS 23.252 3.539 PERCENT ______________________________________________________________________________ PRIOR-VISIT STATUS NEW PT OLD PT OLD PT TOTAL NEWPROB OLDPROB ALL 36875 6024 5736 25115 RECORDS 697082010 97545363 142410663 457125984 VISITS 100.000 13.993 20.430 65.577 PERCENT ______________________________________________________________________________ VISIT DISPOSITION NO RETURN RETURN ADMIT TO OTHR DIS- TOTAL FOLLOWUP IF NEEDED SPEC TIME HOSPITAL POSITION ALL 36875 2650 9063 24082 359 1546 RECORDS 697082010 60569909 192523446 427417837 5580384 26589573 VISITS 100.000 8.689 27.618 61.315 0.801 3.814 PERCENT ______________________________________________________________________________ NUMBER OF MEDICATION CODES THIS VISIT NO 1 2 3 4 5 TOTAL DRUGS DRUG DRUGS DRUGS DRUGS DRUGS ALL 36875 15057 10110 5717 2828 1407 710 697082010 248823738 207368219 120560370 57737776 28504250 14113191 100.000 35.695 29.748 17.295 8.283 4.089 2.025 6 DRUGS 1046 RECORDS 19974466 VISITS 2.865 PERCENT ______________________________________________________________________________ B. DRUG MENTIONS ______________________________________________________________________________ PATIENT AGE TOTAL < 15 15-24 25-44 45-64 65-74 75+ ALL 45482 4956 2514 10293 11978 8254 7487 REC 926132038 142521112 53338471 204466083 226252317 156425559 143128496 MEN 100.000 15.389 5.759 22.077 24.430 16.890 15.454 PER ______________________________________________________________________________ PATIENT SEX TOTAL FEMALE MALE ALL 45482 27547 17935 RECORDS 926132038 570825291 355306747 MENTIONS 100.000 61.635 38.365 PERCENT ______________________________________________________________________________ PHYSICIAN SPECIALTY TOTAL GEN PRAC INT MED PEDIATRICS GEN SURG OB-GYNS ALL 45482 9035 8519 3153 1034 1447 926132038 269191420 207497003 103454529 8179422 38196136 100.000 29.066 22.405 11.171 0.883 4.124 ORTH SUR CARD VAS DERMATOL UROLOGY PSYCHIAT NEUROLOGY 1499 3731 2171 688 3305 1730 17860432 41616194 28748373 8222668 29213641 11901542 1.928 4.494 3.104 0.888 3.154 1.285 OPHTHALM OTOLARYN OTHER 2569 1615 4986 RECORDS 40902912 13946109 107201657 MENTIONS 4.417 1.506 11.575 PERCENT ______________________________________________________________________________ NATIONAL DRUG CODE DIRECTORY DRUG CLASSES TOTAL 01 02 03 04 05 06 ALL 45482 323 21 5188 808 6801 4606 926132038 5854369 509698 127763827 15021672 132356287 65895322 100.000 0.632 0.055 13.795 1.622 14.291 7.115 07 08 09 10 11 12 13 277 1969 2155 3900 1135 2976 1507 7853629 42566807 44987534 85154090 32548609 52771852 22105828 0.848 4.596 4.858 9.195 3.514 5.698 2.387 14 15 16 17 18 19 20 357 2246 247 5481 164 4151 1170 REC 6577221 37783260 5202622 112359630 3545842 99630074 25643865 MEN 0.710 4.080 0.562 12.132 0.383 10.758 2.769 PER 01 = Anesthetics, 02= Antidotes, 03 = Antimicrobial agents, 04 = Hematologic agents, 05 = Cardiovascular-renal drugs, 06 = Central Nervous System, 07 = Radiopharmaceutical/contrast media, 08 = Gastrointestinal agents, 09 = Metabolic and nutrient agents, 10 = Hormones and agents affecting hormonal mechanisms, 11 = Immunologic agents, 12 = Skin/mucous membrane, 13 = Neurologic drugs, 14 = Oncolytics, 15 = Ophthalmic drugs, 16 = Otologic drugs, 17 = Drugs used for relief of pain, 18 = Antiparasitic agents, 19 = Respiratory tract drugs, 20 = Unclassified/miscellaneous, 21 = Homeopathic products (no mentions in 1995). VI. Appendix I Relative Standard Errors The standard error is primarily a measure of the sampling variability that occurs by chance because only a sample is surveyed, rather than the entire universe. The relative standard error (RSE) of an estimate is obtained by dividing the standard error of the estimate by the estimate itself and is expressed as a percentage of the estimate. Tables I and II show relative standard errors for a wide range of visit estimates and drug mention estimates, including the lowest reliable estimate, by physician specialty. (Estimates with a relative standard error greater than 30 percent are considered unreliable by the standards of the National Center for Health Statistics. It should also be noted that estimates based on fewer than 30 sample records are considered unreliable regardless of the magnitude of the relative standard error.) The following formulas can be used to calculate relative standard errors for visit estimates and drug mention estimates: For aggregate estimates, approximate relative standard errors can be cal- culated using the following general formula, where "x" is the aggregate of patient visits or drug mentions in thousands, and coefficients "A" and "B" are obtained from table III: To obtain the RSE(x), divide B by x and add result to A, take square root of that result and multiply by 100. For estimates of percent, approximate relative standard errors can be calculated using the following general formula, where "p" is the percent of visits or mentions, "x" is the denominator of the percent in thousands, and coefficient "B" is obtained from table III: To obtain the RSE(p), multiply B by (1 - p), divide the result by the product of p * x, take square root of that result and multiply by 100. For estimates of visit rates in which the numerator is the number of visits for a particular characteristic and the denominator is the total U.S. population or one of the age-sex-race groups of the total population, the relative standard error is equivalent to the relative standard error of the numerator, as shown above in the paragraph on aggregate estimates. For additional information, contact the Ambulatory Care Statistics Branch at (301) 436-7132. IMPORTANT NOTE: The relative standard errors shown for doctors of osteopathy in Tables I and II are appropriate for analyses of NAMCS data in which visits to osteopaths are analyzed separately from all other visits. The relative standard errors shown for all other specialties, however, have been computed for use with estimates in which doctors of osteopathy have been aggregated with all other specialties, according to their self-designated practice specialty. For those who wish to analyze NAMCS visit data for MDs only, excluding all DOs, please contact the Ambulatory Care Statistics Branch for additional information. Table I. Approximate relative standard errors for selected estimates of office visits by physician specialty: National Ambulatory Medical Care Survey: 1995 Estimated number Physician specialty of office visit All in thousands specialties GFP IM PED GS OBG ORS CD DER Relative standard error in percent 100 69.7 69.0 57.6 63.4 31.1 56.6 37.4 34.6 37.8 200 49.4 49.3 41.2 45.4 23.2 40.7 27.1 26.0 28.2 300 40.4 40.6 34.0 37.5 19.9 33.8 22.6 22.4 24.2 400 35.1 35.5 30.0 32.8 18.0 29.8 20.0 20.4 21.9 500 31.4 32.0 26.9 29.7 16.8 27.1 18.3 19.1 20.4 700 26.7 27.5 23.3 25.6 15.3 23.6 16.1 17.5 18.6 1,000 22.5 23.6 20.1 22.1 14.0 20.6 14.2 16.2 17.1 2,000 16.2 18.0 15.5 17.0 12.4 16.4 11.6 14.5 15.1 3,000 13.5 15.7 13.6 15.0 11.8 14.8 10.6 13.9 14.4 4,000 12.0 14.4 12.6 13.8 11.5 13.9 10.1 13.6 14.0 5,000 10.9 13.5 12.0 13.1 11.3 13.3 9.8 13.4 13.8 7,000 9.5 12.5 11.2 12.2 11.1 12.6 9.4 13.2 13.5 10,000 8.4 11.7 10.5 11.5 10.9 12.1 9.1 13.0 13.3 20,000 6.8 10.6 9.7 10.6 10.7 11.4 8.7 12.8 13.1 30,000 6.2 10.3 9.4 10.3 10.7 11.2 8.6 12.7 13.0 40,000 5.9 10.1 9.3 10.2 10.6 11.1 8.5 12.7 13.0 50,000 5.6 10.0 9.2 10.1 10.6 11.0 8.5 12.7 12.9 70,000 5.4 9.8 9.1 10.0 10.6 10.9 8.4 12.7 12.9 100,000 5.2 9.7 9.0 9.9 10.6 10.9 8.4 12.6 12.9 200,000 5.0 9.6 8.9 9.8 10.5 10.8 8.3 12.6 12.9 300,000 4.9 9.6 8.9 9.7 10.5 10.8 8.3 12.6 12.9 400,000 4.8 9.5 8.9 9.7 10.5 10.8 8.3 12.6 12.8 500,000 4.8 9.5 8.9 9.7 10.5 10.8 8.3 12.6 12.8 700,000 4.8 9.5 8.9 9.7 10.5 10.8 8.3 12.6 12.8 NOTE: The lowest reliable estimates for each of the above specialties are as follows: All specialties - 551,000 visits General and family practice (GFP) - 578,000 Internal medicine (IM) - 395,000 Pediatrics (PED) - 488,000 General surgery (GS) - 109,000 Obstetrics and gynecology (OBG) -394,000 Orthopedic surgery (ORS) - 161,000 Cardiovascular diseases (CD) - 140,000 Dermatology (DER) - 172,000 Estimates below these figures have relative standard errors greater than 30 percent and are considered unreliable by NCHS standards. However, if the estimate is based on fewer than 30 sample records, it is considered to be unreliable regardless of the magnitude of the relative standard error. See "IMPORTANT NOTE" on page 1. Table I. Approximate relative standard errors for selected estimates of office visits by physician specialty: National Ambulatory Medical Care Survey: 1995 - con. Estimated number Physician specialty of office visits in thousands URO PSY NEUR OPH OTO OTHER DO Relative standard error in percent 100 38.6 33.1 30.1 42.4 34.2 57.5 40.1 200 29.3 25.3 24.0 30.9 25.4 41.2 30.0 300 25.5 22.1 21.6 26.0 21.7 34.0 25.6 400 23.3 20.3 20.3 23.1 19.6 29.8 23.2 500 21.9 19.2 19.5 21.2 18.3 26.9 21.6 700 20.2 17.8 18.5 18.8 16.5 23.3 19.6 1,000 18.8 16.7 17.7 16.8 15.1 20.1 18.0 2,000 17.1 15.2 16.7 14.1 13.3 15.6 15.9 3,000 16.5 14.7 16.4 13.0 12.6 13.7 15.1 4,000 16.1 14.5 16.2 12.5 12.3 12.7 14.7 5,000 15.9 14.3 16.1 12.1 12.0 12.1 14.5 7,000 15.7 14.1 16.0 11.7 11.8 11.3 14.2 10,000 15.5 14.0 15.9 11.4 11.6 10.6 14.0 20,000 15.3 13.8 15.8 11.0 11.4 9.9 13.7 30,000 15.3 13.8 15.8 10.9 11.3 9.6 13.7 40,000 15.2 13.7 15.8 10.8 11.3 9.4 13.6 50,000 15.2 13.7 15.8 10.8 11.2 9.4 13.6 70,000 15.2 13.7 15.7 10.8 11.2 9.3 13.6 100,000 15.2 13.7 15.7 10.7 11.2 9.2 13.5 200,000 15.1 13.7 15.7 10.7 11.2 9.1 13.5 300,000 15.1 13.7 15.7 10.7 11.2 9.1 13.5 400,000 15.1 13.7 15.7 10.7 11.1 9.0 13.5 500,000 15.1 13.7 15.7 10.7 11.1 9.0 13.5 700,000 15.1 13.7 15.7 10.7 11.1 9.0 13.5 NOTE: The lowest reliable estimates for each of the above specialties are as follows: Urology (URO) - 189,000 visits Otolaryngology (OTO) - 135,000 Psychiatry (PSY) - 128,000 All other (OTHER) - 394,000 Neurology (NEUR) - 101,000 Doctors of osteopathy (DO) - 199,000 Ophthalmology (OPH) - 215,000 Estimates below these figures have relative standard errors greater than 30 percent and are considered unreliable by NCHS standards. However, if the estimate is based on fewer than 30 sample records, it is considered to be unreliable regardless of the magnitude of the relative standard error. See "IMPORTANT NOTE" on page 1. Table II. Approximate relative standard errors for selected estimates of drug mentions at office visits by physician specialty: National Ambulatory Medical Care Survey, 1995 Estimated number Physician specialty of drug mention All in thousands specialties GFP IM PED GS OBG ORS CD DER Relative standard error in percent 100 106.1 82.2 83.6 63.6 39.6 76.3 45.2 51.4 42.8 200 75.1 58.6 59.5 45.8 32.2 54.7 33.0 38.2 32.1 300 61.4 48.3 48.9 38.1 29.3 45.3 27.8 32.6 27.6 400 53.2 42.2 42.8 33.6 27.7 39.8 24.8 29.4 25.0 500 47.7 38.0 38.3 30.6 26.7 36.0 22.8 27.3 23.3 700 40.4 32.6 32.8 26.7 25.5 31.2 20.3 24.7 21.3 1,000 33.9 27.9 27.9 23.4 24.6 27.1 18.2 22.6 19.6 2,000 24.2 21.2 20.8 18.8 23.5 21.2 15.4 19.8 17.4 3,000 20.0 18.4 17.8 17.0 23.1 18.9 14.3 18.7 16.6 4,000 17.5 16.8 16.2 16.0 22.9 17.6 13.7 18.2 16.2 5,000 15.8 15.8 15.0 15.4 22.8 16.7 13.4 17.9 16.0 7,000 13.6 14.6 13.7 14.7 22.6 15.7 13.0 17.5 15.7 10,000 11.7 13.5 12.5 14.1 22.5 15.0 12.7 17.2 15.5 20,000 9.0 12.3 11.1 13.4 22.4 14.0 12.3 16.9 15.2 30,000 7.9 11.8 10.6 13.1 22.4 13.6 12.1 16.7 15.1 40,000 7.3 11.6 10.3 13.0 22.4 13.5 12.1 16.7 15.1 50,000 6.9 11.4 10.1 12.9 22.4 13.4 12.0 16.6 15.0 70,000 6.4 11.2 9.9 12.9 22.3 13.2 12.0 16.6 15.0 100,000 6.0 11.1 9.8 12.8 22.3 13.1 12.0 16.6 15.0 200,000 5.6 11.0 9.6 12.7 22.3 13.0 11.9 16.5 15.0 300,000 5.4 10.9 9.5 12.7 22.3 13.0 11.9 16.5 15.0 400,000 5.3 10.9 9.5 12.7 22.3 13.0 11.9 16.5 14.9 500,000 5.2 10.9 9.5 12.7 22.3 13.0 11.9 16.5 14.9 700,000 5.2 10.9 9.5 12.7 22.3 13.0 11.9 16.5 14.9 1,000,000 5.1 10.8 9.4 12.7 22.3 13.0 11.9 16.5 14.9 NOTE: The lowest reliable estimates for each of the above specialties are as follows: All specialties - 1,284,000 mentions General and family practice (GFP) - 849,000 Internal medicine (IM) - 851,000 Pediatrics (PED) - 525,000 General surgery (GS) - 267,000 Obstetrics and gynecology (OBG) - 772,000 Orthopedic surgery (ORS) - 251,000 Cardiovascular diseases (CD) - 379,000 Dermatology (DER) - 238,000 Estimates below these figures have relative standard errors greater than 30 percent and are considered unreliable by NCHS standards. However, if the estimate is based on fewer than 30 sample records, it is considered unreliable regardless of the magnitude of the relative standard error. See "IMPORTANT NOTE" on page 1. Table II. Approximate relative standard errors for selected estimates of drug mentions at office visits by physician specialty: National Ambulatory Medical Care Survey, 1995 - con. Estimated number Physician specialty of drug mentions in thousands URO PSY NEUR OPH OTO OTHER DO Relative standard error in percent 100 44.0 41.0 40.2 53.0 36.3 74.7 53.6 200 33.7 30.9 34.1 38.7 27.6 53.6 39.6 300 29.5 26.7 31.8 32.5 24.0 44.4 33.7 400 27.2 24.4 30.6 29.0 22.0 38.9 30.3 500 25.7 22.8 29.8 26.6 20.7 35.3 28.1 700 23.9 20.9 28.9 23.6 19.1 30.6 25.3 1,000 22.4 19.4 28.3 21.1 17.8 26.5 23.0 2,000 20.5 17.4 27.4 17.7 16.1 20.8 19.9 3,000 19.9 16.7 27.2 16.4 15.5 18.5 18.8 4,000 19.5 16.3 27.0 15.7 15.2 17.3 18.2 5,000 19.3 16.1 26.9 15.3 15.0 16.5 17.9 7,000 19.1 15.9 26.8 14.8 14.8 15.5 17.4 10,000 18.9 15.7 26.8 14.4 14.7 14.7 17.1 20,000 18.7 15.4 26.7 13.9 14.5 13.8 16.7 30,000 18.6 15.3 26.7 13.8 14.4 13.5 16.6 40,000 18.6 15.3 26.6 13.7 14.4 13.3 16.5 50,000 18.6 15.3 26.6 13.7 14.3 13.2 16.5 70,000 18.6 15.3 26.6 13.6 14.3 13.1 16.5 100,000 18.5 15.2 26.6 13.6 14.3 13.0 16.4 200,000 18.5 15.2 26.6 13.5 14.3 12.9 16.4 300,000 18.5 15.2 26.6 13.5 14.3 12.8 16.4 400,000 18.5 15.2 26.6 13.5 14.3 12.8 16.4 500,000 18.5 15.2 26.6 13.5 14.3 12.8 16.4 700,000 18.5 15.2 26.6 13.5 14.3 12.8 16.3 1,000,000 18.5 15.2 26.6 13.5 14.3 12.8 16.3 NOTE: The lowest reliable estimates for each of the above specialties are as follows: Urology (URO) - 286,000 mentions Otolaryngology (OTO) - 161,000 Psychiatry (PSY) - 217,000 All other (OTHER) - 735,000 Neurology (NEUR) - 472,000 Doctors of osteopathy (DO) - 412,000 Ophthalmology (OPH) - 366,000 Estimates below these figures have relative standard errors greater than 30 percent and are considered unreliable by NCHS standards. However, if the estimate is based on fewer than 30 sample records, it is considered to be unreliable regardless of the magnitude of the relative standard error. See "IMPORTANT NOTE" on page 1. Table III. Coefficients appropriate for determining relative standard errors by type of estimate and physician specialty: National Ambulatory Medical Care Survey, 1995 Coefficient for use with estimates in thousands Type of estimate and physician specialty A B Visits Overall totals 0.002215 48.298 General and family practice 0.008996 46.757 Internal medicine 0.007822 32.389 Pediatrics 0.009340 39.319 General surgery 0.011084 8.547 Obstetrics and gynecology 0.011514 30.856 Orthopedic surgery 0.006900 13.297 Cardiovascular diseases 0.015865 10.354 Dermatology 0.016471 12.618 Urology 0.022864 12.648 Psychiatry 0.018671 9.070 Neurology 0.024702 6.565 Ophthalmology 0.011328 16.847 Otolaryngology 0.012399 10.456 All other specialties 0.008103 32.249 Drug mentions Overall totals 0.002520 112.321 General and family practice 0.011689 66.408 Internal medicine 0.008850 68.994 Pediatrics 0.015967 38.812 General surgery 0.049745 10.746 Obstetrics and gynecology 0.016714 56.571 Orthopedic surgery 0.014111 19.003 Cardiovascular diseas 0.027244 23.732 Dermatology 0.022308 16.098 Urology 0.034228 15.899 Psychiatry 0.023053 14.499 Neurology 0.070765 9.064 Ophthalmology 0.018135 26.295 Otolaryngology 0.020356 11.160 All other specialties 0.016305 54.119 NOTE: These coefficients apply to NAMCS data where doctors of osteopathy (DOs) have been aggregated with doctors of medicine (MDs) according to their self-designated practice specialty. For those who wish to conduct a separate analysis on doctors of osteopathy, the A and B coefficients for use with visit estimates in thousands are .01816 and 14.287, respectively. The coefficients for estimates of drug mentions in thousands are 0.02669 and 26.072. To perform analyses of NAMCS data on visits to MDs only, excluding all DOs, please contact the Ambulatory Care Statistics Branch for additional information. VII. 1995 NAMCS PATIENT RECORD FORM - INSTRUCTIONS AND DEFINITIONS ITEM 1 - DATE OF VISIT The month, day, and year should be recorded in figures, for example, 5/17/95 for May 17, 1995. The physician's assistant may often record the date on a number of forms in advance, or enter the date at the end of the day if the doctor has not done this. ITEM 2 - ZIP CODE The patient's five-digit zip code should be recorded here. ITEM 3 - DATE OF BIRTH The month, day, and year of the patient's birth should be recorded here, in the same fashion as Date of Visit, above. This information wi