Drug prescribing for ambulatory patients 85 years of age and older.

Drug prescribing for ambulatory patients greater than or equal to 85 years of age was studied using data from the 1980 National Ambulatory Medical Care Survey (NAMCS) on office visits to physicians. NAMCS is a survey by the US National Center for Health Statistics, which collected information on office visits and extrapolated the results to the US population. Of the 575.7 million office visits by all ages, 6.8 million (1 per cent) were by persons greater than or equal to 85 years of age, and 64 per cent involved females. Ninety per cent of the total office visits of those greater than or equal to 85 years were with a physician who had seen them before; 94 per cent were with MDs as compared with DOs; 56 per cent were with general practitioners or internists; and 95 per cent had some type of follow-up planned. The most frequent duration of the office visit was 11-15 minutes (36 per cent). The most frequent diagnostic class was diseases of the circulatory system. The survey physicians were asked to list all drugs, new or already in use by the patient, that were ordered, administered, or prescribed during the visit. The authors converted the drug brand names to their nonproprietary or generic name component(s); each active ingredient of combination products was treated as a separate drug entity. All drug analyses used generic names. Thirty-two per cent of visits did not involve the use of any drug, 21 per cent involved one drug; 12 per cent, two drugs; and 16 per cent, three drugs. Cardiovascular-renal drugs were the most frequently mentioned. One-third of the visits involved the use of one or more drugs that have psychologic effects, either intended or as side effects. Three per cent of the office visits involved the use of two or more drugs that had the potential for clinically important interactions.