Review Article Prevalence and Factors Associated With Polypharmacy in Long-Term Care Facilities: A Systematic Review Natali Jokanovic BPharm (Hons) a, b, *, Edwin C.K. Tan PhD a , Michael J. Dooley PhD a, b , Carl M. Kirkpatrick PhD a , J. Simon Bell PhD a a Faculty of Pharmacy and Pharmaceutical Sciences, Centre for Medicine Use and Safety, Monash University, Melbourne, Australia b Pharmacy Department, Alfred Hospital, Melbourne, Australia Keywords: Long-term care nursing homes polypharmacy aged homes for the aged abstract Objective: The objective of the study was to investigate the prevalence of, and factors associated with, polypharmacy in long-term care facilities (LTCFs). Methods: MEDLINE, EMBASE, International Pharmaceutical Abstracts, Cumulative Index to Nursing and Allied Health Literature, and the Cochrane Library were searched from January 2000 to September 2014. Primary research studies in English were eligible for inclusion if they fulfilled the following criteria: (1) polypharmacy was quantitatively defined, (2) the prevalence of polypharmacy was reported or could be extracted from tables or figures, and (3) the study was conducted in a LTCF. Methodological quality was assessed using an adapted version of the Joanna Briggs Institute Critical Appraisal Checklist. Results: Forty-four studies met the inclusion criteria and were included. Polypharmacy was most often defined as 5 or more (n ¼ 11 studies), 9 (n ¼ 13), or 10 (n ¼ 11) medications. Prevalence varied widely between studies, with up to 91%, 74%, and 65% of residents taking more than 5, 9, and 10 medications, respectively. Seven studies performed multivariate analyses for factors associated with polypharmacy. Positive associations were found for recent hospital discharge (n ¼ 2 studies), number of prescribers (n ¼ 2), and comorbidity including circulatory diseases (n ¼ 3), endocrine and metabolic disorders (n ¼ 3), and neurological motor dysfunctioning (n ¼ 3). Older age (n ¼ 5), cognitive impairment (n ¼ 3), disability in activities of daily living (n ¼ 3), and length of stay in the LTCF (n ¼ 3) were inversely associated with polypharmacy. Conclusions: The prevalence of polypharmacy in LTCFs is high, varying widely between facilities, geographical locations and the definitions used. Greater use of multivariate analysis to investigate factors associated with polypharmacy across a range of settings is required. Longitudinal research is needed to explore how polypharmacy has evolved over time. Ó 2015 AMDA e The Society for Post-Acute and Long-Term Care Medicine. More than 50% of older adults experience at least 2 chronic dis- eases. 1,2 Multimorbidity often leads to the use of multiple medica- tions. This is referred to as polypharmacy. Polypharmacy is commonly defined according to a predetermined number of medications or as the inappropriate or unnecessary use of medications. 3,4 Development of new home-based models of care has meant that residents are often older and frailer on admission to long-term care facilities (LTCFs) with more complex care needs than in the past. 5 Residents often have multiple comorbidities with resulting com- plex medication regimens. Newer pharmacological treatments, the ongoing use of preventive medications, and strict adherence to practice guidelines for multiple single diseases contribute to the increasing prevalence of polypharmacy. 6,7 Polypharmacy presents challenges for those providing care and exposes residents to an increased risk of adverse drug events. Poly- pharmacy has considerable workforce and management implications for providers of long-term care. 8 This is due to the need for skilled staff to be available to assist residents with administering their medications. 9 The burden of polypharmacy for providers of long-term care may be compounded by poor medication packaging, lack of drug information, and frequent regimen changes. Polypharmacy has been associated with adverse drug reactions (ADRs), drug-drug interactions, nonadherence, functional decline, The authors declare no conflicts of interest. This study was commissioned and funded by the Ageing and Aged Care Branch, Department of Health and Human Services, State Government of Victoria. * Address correspondence to Natali Jokanovic, PhD Candidate, Faculty of Phar- macy and Pharmaceutical Sciences, Centre for Medicine Use and Safety, Monash University (Parkville Campus), 381 Royal Parade, Parkville, Victoria 3052, Australia. E-mail address: Natali.Jokanovic@monash.edu (N. Jokanovic). JAMDA journal homepage: www.jamda.com http://dx.doi.org/10.1016/j.jamda.2015.03.003 1525-8610/Ó 2015 AMDA e The Society for Post-Acute and Long-Term Care Medicine. JAMDA xxx (2015) e1ee12