[Factors associated with chronic drug consumption in the elderly].
BACKGROUND: To determine chronic drug intake in the non-institutionalised elderly population and identify factors associated with polypharmacy. PATIENTS AND METHODS: Cross-sectional study by means of home interview. 1,015 elderly individuals were selected systematically from the 1991 municipal electoral list of Albacete, Spain (level of confidence 95%, precision 3%, response rate 93.8%). The questionnaire included, disability scales (Minimental test, index of Katz and Lawton-Brody, Yesavage scale and DUKE-UNC questionnaire), a self-preceivement of health, demographic data and qualitative and quantitative information about drug intake. We employed the anatomic classification of drugs to obtain a profile of consumption. RESULTS: 75% of those interviewed admitted to taking medication chronically (CI 95%: 72.6-78.6). The mean number of drugs was 3.17 +/- 1.94 SD. Intake was significantly higher in women (p = 0.01), widows (p = 0.04), those of lower social status (p = 0.01), greater age (p < 0.02), and a greater number of illnesses (p < 0.001), more frequent users of health resources (p < 0.001), those physically dependent (p < 0.001) and those suffering from depression or cognitive impairment (p = 0.001). The most commonly taken drugs were: cardioactive drugs (22.1%), diuretics (19.4%) and vasodilators (14.2%). Using logistic regression analysis we found that the factors associated with higher drug intake were: three or more ilnesses (OR = 2.24), poor self-assessed status of health (OR = 1.45), physical dependence (OR = 1.59), age greater than 74 years (OR = 1.63), depression (OR = 1.68), > or = 4 contacts with health providers over a three-month period (OR = 2.73) and previous hospital admissions (OR = 2.67). CONCLUSIONS: The high intake of drugs by the elderly is determined, among other factors, by sociodemographic considerations, the subject's perceived status of health and different forms of disability. These factors should be taken into account by health professionals when planning a rational use of drugs. There is a high consumption of peripheral vasodilators despite their scanty therapeutic value.