Impact of inappropriate drug use on health services utilization among representative older community-dwelling residents.

BACKGROUND: There is limited objective information regarding the impact of drugs identified as inappropriate by drug utilization review (DUR) or the Beers drugs-to-avoid criteria on health service use.

OBJECTIVE: The goal of this study was to examine the predictive validity of DUR and the Beers criteria employed to define inappropriate drug use in representative community residents, aged >or=68 years, as determined by the relationship of these criteria to health service use in older community residents.

METHODS: Data came from participants in the Duke University Established Populations for Epidemiologic Studies of the Elderly seen in 1989/1990 and for whom information was also available 3 years later. Two sets of inappropriate drug use criteria were examined: (1) DUR regarding dosage, duration, duplication, and drug-drug and drug-disease interactions; and (2) the Beers criteria, applied to drug use reported in an in-home interview. Outpatient visits and nursing-home entry were determined by personal report; hospitalization information came from Medicare Part A files from the Centers for Medicare and Medicaid Services.

RESULTS: A total of 3165 participants were available at the fourth interview in 1989/1990. The majority were aged >74 years (51.1%), white (64.8%), women (64.7%), had fair or poor health (77.0%), consistently saw the same physician (86.9%), and possessed supplemental health insurance (62.8%). Use of inappropriate drugs meeting DUR criteria, especially for drug-drug or drug-disease interaction problems, was associated with increased outpatient visits (P<0.05) but not with time to hospitalization or time to nursing home entry. The use of inappropriate drugs according to the Beers criteria was associated with reduced time to hospitalization (adjusted hazard ratio, 1.20; 95% CI, 1.04-1.39) but not to outpatient visits or nursing home entry.

CONCLUSIONS: Our data suggest that in representative community residents aged >or=68 years, current criteria for inappropriate drug use should be used with caution in evaluating quality of care because they have minimal impact on use of health services. We found increases only in the use of outpatient services (with DUR) and more rapid use of hospitalization (with the Beers criteria).