Objective: To describe the use of prescription drug therapy, especially polypharmacy, in an elderly general population; to relate that use to age, gender, and different types of healthcare utilization; and to investigate the influence of selection of different time windows on the result of the quantity as well as the categories of drugs used.
Methods: Data on a sample of 5000 patients aged 65-90 years in 1996 were derived from the General Practice Research Database (GPRD). The population covered by GPRD is broadly representative of the UK population treated in general practice. Drug use was assessed using 2 time windows - current use of individual drugs on a random day (index date) and 1 month following the index date. Healthcare utilization was analyzed by use of information on visits to general practitioners (GPs), hospitalizations, and referrals to specialists.
Results: Women used more drugs than men; however, the prevalence of polypharmacy, defined as concomitant use of > or =5 drugs, was similar in both genders. The most frequently used therapeutic groups were cardiovascular, central nervous, and gastrointestinal system drugs. Almost 80% of both women and men visited a GP at least once a year. Overall, women used more ambulatory care services and men were hospitalized more often. Use of random date compared with 1-month period resulted in a significant underestimation of the amount of drugs used for acute conditions and, consequently, the risk of polypharmacy.
Conclusions: The overall results confirm the findings in earlier studies suggesting that the GPRD might be a useful tool in further studies on prescription drug use among elderly persons. More information on the appropriateness of drug use is needed to prevent overuse as well as underuse of medications among the elderly.