NONCOMPLIANCE IN ELDERLY PEOPLE - EVALUATION OF RISK-FACTORS BY LONGITUDINAL DATA-ANALYSIS

Studies on risk factors for drug non-compliance have not taken into ac count the possibility of correlated outcomes. We therefore conducted a study into risk factors for non-compliance (longitudinal data analysi s). Data were obtained from interviews and pharmacy records in a cross -sectional survey in Amsterdam. The subjects were 157 elderly people a ged 70 years or older. Of these subjects, 37 were residents of a home for the elderly, 40 were community-dwelling elderly who needed to be v isited regularly by a district nurse, and 80 were community-dwelling e lderly who did not need to be visited by a district nurse. Most drugs (78%) were used according to the directions; the remainder (22%) were not used as intended. Odds ratios (95% confidence intervals) for non-c ompliance for moderate and poor/wrong knowledge of the purpose of a dr ug as compared with good/correct knowledge were 2.8 (1.2-6.7) and 4.2 (1.5-12), respectively. Drug regimens of two times daily and more than two times daily were associated with odds ratios for non-compliance o f 4.5 (1.6-12) and 4.2 (1.7-11), respectively, compared to a regimen o f once daily. Compliance increased if a drug was prescribed by a speci alist instead of a general practitioner [odds ratio 0.1 (0.04-0.4)]. T here was no significant relation between compliance and the number of drugs prescribed to a patient, sex, age, living situation, patient gro up, or perceived effect. This study, which was based on longitudinal d ata analysis, demonstrates that in elderly people non-compliance with drug therapy is related to the knowledge of purpose of a drug, the com plexity of a drug regimen, and the type of prescriber. The positive as sociation between compliance and the number of drugs prescribed found in former studies was not confirmed.