Impact of inappropriate drug use among hospitalized older adults

Objective: Criteria for inappropriate drug use developed by Beers have been widely used in drug utilization reviews as the basis for educational materials and to assess the quality of prescribing. However, there is inconclusive evidence that these criteria can impact on patient outcomes. The objective of this study was to evaluate the impact of inappropriate drug use on all-cause mortality, adverse drug reactions (ADRs) and length of stay among in-hospital patients. Methods: We performed a retrospective, cohort study on 5,152 patients aged 65 years or older admitted to 81 hospitals in Italy between 1997 and 1998. Inappropriate drug use was defined by 2003 Beers criteria. Outcomes of the study were: (a) in-hospital mortality; (b) incidence of ADR occurring during hospital stay; (c) length of hospital stay 13 days or more. Results: The mean age of 5,152 participants was 78.8 years (standard deviation=8.4 years), and 2,463 (47.8%) were men. During hospital stay, 1,475 (28.6% of the study sample) patients received one or more inappropriate drugs. After adjusting for potential confounders, use of inappropriate drugs was not associated significantly with either mortality [odds ratio (OR) 1.05; 95% confidence intervals (CI): 0.75-1.48], ADR (OR 1.20; 95% CI: 0.89-1.61) or length of stay 13 days or more (OR 1.09-95% CI: 0.95-1.25). Conclusions: This study did not show any significant effect of inappropriate drug use defined by Beers 2003 criteria on health outcomes among hospitalized older adults. Further studies conducted in different settings, using additional health outcomes and alternate measures of inappropriate drug use, are needed.