Inappropriate medication use among frail elderly inpatients.

Background: Inappropriate prescribing in frail elderly inpatients has not received as much investigation as in frail elderly nursing home patients.

Objective: To determine the prevalence and predictors of inappropriate prescribing for hospitalized frail elderly patients.

Methods: The study was conducted at 11 Veterans Affairs Medical Centers and involved a sample of 397 frail elderly inpatients. Inappropriate prescribing was measured by physician-pharmacist pair's consensus ratings for 10 criteria on the Medication Appropriateness Index (MAI). The MAI ratings generated a weighted score of 0-18 per medication (higher score = more inappropriate) and were summed across medications to achieve a patient score.

Results: Overall, 365 (91.9%) patients had > or =1 medications with > or =1 MAI criteria rated as inappropriate. The most common problems involved expensive drugs (70.0%), impractical directions (55.2%), and incorrect dosages (50.9%). The most common drug classes with appropriateness problems were gastric (50.6%), cardiovascular (47.6%), and central nervous system (23.9%). The mean +/- SD MAI score per person was 8.9 +/- 7.6. Stepwise ordinal logistic regression analyses revealed that both the number of prescription (adjusted OR 1.28; 95% CI 1.21 to 1.36) and nonprescription drugs (adjusted OR 1.17; 95% CI 1.06 to 1.29) were related to higher MAI scores. Analyses excluding the number of drugs revealed that the Charlson index (adjusted OR 1.62; 95% CI 1.12 to 2.35) and fair/poor self-rated health (adjusted OR 1.15; 95% CI 1.05 to 1.26) were related to higher MAI scores.

Conclusions: Inappropriate drug prescribing is common for frail elderly veteran inpatients and is related to polypharmacy and specific health status characteristics.