Impact of inappropriate drug use on mortality and functional status in representative community dwelling elders

BACKGROUND. The predictive validity of Drug Utilization Review (DUR) and drugs-to-avoid criteria in elders is unknown. OBJECTIVES. To evaluate the relationship between use of inappropriate drugs as determined by these explicit criteria and mortality and decline in functional status in community dwelling elders. RESEARCH DESIGN. Cohort study. SUBJECTS. The fourth wave (3234 participants) of the Duke Established Populations for Epidemiologic Studies of the Elderly. MEASURES. Two sets of inappropriate drug-use criteria: (1) DUR with respect to dosage, duplication, drug-drug interactions, duration, and drug-disease interactions; and (2) Beers-modified criteria regarding drugs-to-avoid were applied to drug use reported in an in-home interview. Death was identified from the National Death Index; change in four functional status measures (basic self-care, intermediate self-care, complex self-management, physical function) was determined during the following 3 years. RESULTS. Use of inappropriate drugs identified by either set of criteria was not significantly associated with mortality. The drugs-to-avoid criteria identified no significant associations between use of these drugs and decline in functional status. With DUR criteria, however, the association between use of inappropriate drugs and basic selfcare was significant and pronounced among those with drug-drug or drug-disease interaction problems (Adj. OR 2.04; 95% CI 1.32-3.16). CONCLUSIONS. Identifying the impact of inappropriate drug use may depend on the criteria applied. Further studies are needed that measure additional outcomes and use alternate measures of inappropriate drug use.