Drug-prescribing patterns in old age. A study of the impact of hospitalization on drug prescriptions and follow-up survey in patients 75 years and older.

A prospective drug surveillance study was undertaken in 300 elderly patients admitted to a geriatric clinic. Prescribing patterns were determined on admission, at discharge and 3.6 and 18 months after discharge. Patients referred from long-term care institutions were on significantly more drugs than non-institutionalized subjects. A 34% reduction in the number of medicines prescribed at discharge was accompanied by a significant decrease in the mean number of prescriptions per patient, from 4.3 to 2.8, irrespective of whether the patient was institutionalized. Polypharmacy, defined by 5 or more concomitant drugs, declined from 43 to 17%. Dosage schedules were simplified in the majority of patients, as expressed by a significant decrease in the mean number of daily doses to be taken from 6.7 on admission to 4.4 at discharge. Cardiovascular drugs, diuretics and psychotropic drugs accounted for 64% of all drug prescriptions. At discharge, prescription frequencies were reduced for most medication categories, except diuretics and gastrointestinal drugs, which were being taken more often. The prescribing frequency of cardiac glycosides, the single most frequently prescribed drug class, decreased from 60 to 33% of the patients. Three months after discharge, prescribing patterns and frequencies were found to be very similar to the pre-admission situation. Eighteen months after discharge, overall drug use had increased by 15% compared to admission, and polypharmacy was recorded in 54% of patients. It is concluded that a substantial reduction in drug prescriptions was possible in the majority of elderly patients, particularly if they are institutionalized, on admission to a geriatric clinic.(ABSTRACT TRUNCATED AT 250 WORDS)