Use of inappropriate prescription drugs by older people.

OBJECTIVES

To determine the prevalence and predictors of inappropriate drug prescribing defined by expert national consensus panel drug utilization review criteria for community-dwelling older people.

DESIGN

Survey.

SETTING

Five adjacent urban and rural counties in the Piedmont area of North Carolina.

PARTICIPANTS

A stratified random sample of participants from the fourth (n = 3,234) and seventh (n = 2,508) waves of the Duke Established Populations for Epidemiological Studies of the Elderly.

MEASUREMENTS

The prescribing appropriateness for digoxin, calcium channel blockers, angiotensin-converting enzyme inhibitors, histamine(2) receptor antagonists, nonsteroidal antiinflammatory drugs (NSAIDs), benzodiazepines, antipsychotics, and antidepressants as determined by explicit criteria (through Health Care Financing Administration expert consensus panel drug utilization review criteria for dosage, duplication, drug-drug interactions and duration, and U.S. and Canadian expert consensus panel criteria for drug-disease interactions). Multivariable analyses, using weighted data adjusted for sampling design, were conducted to assess the association between inappropriate prescribing and demographic, health-status, and access-to-healthcare factors cross-sectionally and longitudinally.

RESULTS

We found that 21.0 of the fourth wave and 19.2 of the seventh wave participants who used one or more agents from the eight drug classes had one or more elements identified as inappropriate. The therapeutic classes with the most problems were benzodiazepines and NSAIDs. The most common problems were with drug-disease interactions and duration of use. Longitudinal multivariable analyses found that participants who were white (adjusted odds ratio (AOR) = 1.67, 95 confidence interval (CI) = 1.28-2.17), were married (AOR = 1.40, 95% CI = 1.01-1.93), had arthritis (AOR = 1.74, 95% CI = 1.27-2.38), had one or more physical function disabilities (AOR = 1.42, 95% CI = 1.02-1.96), and had inappropriate drugs prescribed at wave 4 (AOR = 6.87, 95% CI = 5.11-9.22) were more likely to have inappropriate prescribing at wave 7.

CONCLUSION

These results indicate that inappropriate prescribing is common among community-dwelling older people and persists over time. Longitudinal studies in older people are needed to examine the impact of inappropriate drug prescribing on health-related outcomes.