Abstracts

Abstract

Background: Potentially inappropriate medications (PIM) increase the risk of adverse effects of drugs in older adults. STOPP Criteria have been used internationally to identify PIM but US data are lacking. Objectives: To determine prevalence of PIM among US older population using STOPP Criteria. Methods: We used fee-for-service Medicare Parts A, B, and D claims data from 2007-2011 to estimate the prevalence of PIM in the US population aged >65 years. PIM was defined by STOPP Criteria, including diagnoses or conditions present in the previous calendar year. We estimated the point prevalence of PIM within each calendar month by dividing the number of older adults with >1 PIM during the month by the number of adults filling >1 prescription. We report the prevalence and used generalized estimating equations (GEE) to account for the dependence of multiple monthly observations of a single person in the estimated 95% confidence intervals (CI). A multivariable model was performed to estimate adjusted Relative Risk (RR) and CI. Results: A total of 23,223, 23,565, 23,670, 22,727 and 24,782 patients were included during 2007, 2008, 2009, 2010 and 2011, respectively. The majority (56.7%) of patients were 75 years or older, 65.6% were women, and 85.5% were white. The point prevalence of PIM was 19.2% (CI: 18.8-19.7) in 2007, 19.2% (CI: 18.7-19.6) in 2008, 18.9% (CI: 18.5-19.4) in 2009, 19.2% (CI: 18.8-19.7) in 2010 and 18.7% (CI: 18.2-19.1) in 2011. Compared to patients age 65-69, those 80-84 and >85 were slightlymore likely to receive a PIM (RR 1.13, CI 1.06-1.21 and RR 1.08; CI 1.02-1.16, respectively). Patients with >1 emergency visit in the previous 12months (RR 1.53; CI 1.48-1.59) were more likely to receive a PIM than those with none. The most common PIMs included drugs affecting musculoskeletal system (20%) and drugs that adversely affect those prone to falls (19.7%). Conclusions: Approximately one in 5 older US adults received at least one PIM. The PIM prevalence was lower than it has been reported using Beers Criteria 2012. Drugs affecting musculoskeletal system and drugs that adversely affect fallers were found to have the highest potential for PIM.