OBJECTIVES To examine the prevalence of potentially inappropriate medication use (PIMs) among community-dwelling older adults in a managed care organization (MCO) and the association between PIMs and selected health care outcomes. DESIGN, MEASURES, ANALYSIS Retrospective cohort study. Participants were 17,971 individuals in the southeast age 65 years and older who were continuously enrolled for a 6- month period from January 1-June 30, PIM use was defined by the Beers criteria; any subject using at least one such drug was defined to be in the PIM group. ICD-9 codes for medical diagnoses were taken from the discharge diagnosis. Comorbidity was measured using the Deyo-adapted Charlson index. Drug-related problems (DRPS) were defined using ICD-9 codes for principal and secondary diagnoses occurring within 30 days after a drug was started. Health care costs, were based on MCO claims data. Donna Fick, PhD, RN 1 ; Lorraine C. Mion, PhD, RN, FAAN 2 ; Diane Spokus, M.Ed 1 1 The Pennsylvania State University, University Park, PA; 2 MetroHealth Campus of Case Western Reserve University School of Medicine, Cleveland, Ohio METHODS Health Outcomes Associated With Potentially Inappropriate Medication Use In Older Adults Adverse drug events (ADEs) are prevalent in the older adult population and pose a major patient safety concern. ADEs arise because of the increasing number of medications required by this age group, pre-existing health conditions, and the pharmacokinetic and pharmacodynamic changes that occur with aging.1, 2 Avoiding use of high-risk drugs is an important strategy in reducing ADEs. INTRODUCTION Table 1. Characteristics of the Study Sample, Medication Use and Overall Cost Forty percent of the 17,971 individuals filled at least 1 PIM prescription, and 13% filled 2 or more PIMs prescriptions. Overall DRP prevalence, among those with at least 1 PIM prescription was 14.3% compared to 4.7% in the non-PIM group (p<0.0001). Those individuals taking 2 or more PIMs had the highest cost and utilization (F=522.2, p<0.0001). IMPLICATIONS These findings should be used to create interventions to decrease the use of PIMS now that we have established the adverse clinical and cost outcomes of their collective use. This study also illustrates the need to study which drugs listed in the Beers criteria cause the most problems. This will require a larger prospective study. ACKNOWLEDGEMENTS Blue Cross Blue Shield of Georgia for data acquisition and data support. Shari Walczak for dissemination expertise. Use of even one PIM by elderly patients increases the likelihood of drug-related problems by nearly 3 fold within 30 days and increases healthcare utilization and costs over 6 months. RESULTS Given the retrospective nature of the study, our measures for drug-related problems are limited in their ability to infer causality and will require further testing in a prospective study. The other limitations of this study are similar to that of other studies that use administrative data: problems with coding, changing reimbursements, high patient turnover, and the limits of the available economic and clinical data. LIMITATIONS Table 4. Chi-square or Fisher’s Exact Tests between Individuals with PIMS & Comparison Individuals for Prevalence of Drug-related Problems (DRP) within 30 Days of a Prescription Table 2. Distribution of Each Potentially Inappropriate Medication (N=17,971)* Table 3. Number of Inappropriate Medications Types