title: Prevalence and factors associated with polypharmacy in older people with cancer.
abstract: OBJECTIVE
  Polypharmacy has been associated with drug-drug interactions, adverse drug events, hospitalisation and increased mortality. The purpose of this study was to investigate the prevalence and factors associated with polypharmacy in older people with cancer.
  
  
  METHODS
  Patients aged≥70 years (n=385) presenting to the medical oncology outpatient clinic at Royal Adelaide Hospital between January 2009 and July 2010 completed a structured data collection instrument. The instrument included domains related to medications, diagnoses, instrumental activities of daily living (IADLs), Karnofsky Performance Scale (KPS), physical function (SF-36), pain (ten-point visual analogue scale, VAS), weight loss (patient self-reported over previous 6 months), exhaustion (CES-D) and distress (ten-point VAS). Frailty was computed using Fried's frailty phenotype. Logistic regression was used to compute unadjusted and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the association between polypharmacy (defined as five or more self-reported daily medications) and clinical parameters.
  
  
  RESULTS
  Polypharmacy was present in 57% (n=221) of patients. When adjusting for age, gender and Charlson Comorbidity Index (CCI), polypharmacy was associated with being pre-frail (OR=2.35, 95%CI=1.43-3.86) and frail (OR=4.48, 95%CI=1.90-10.54) compared to being robust. When adjusting for age, gender, exhaustion, KPS, IADLs, pain and distress, polypharmacy was associated with higher CCI scores (OR=1.58, 95%CI=1.29-1.94) and poorer physical function (OR=1.13, 95%CI=1.06-1.20).
  
  
  CONCLUSIONS
  Polypharmacy is highly prevalent in older people with cancer and associated with impaired physical function and being pre-frail and frail compared to being robust. Research is needed to identify strategies to minimize patients' medication regimens.
authors.affiliation: School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia, justin.turner@unisa.edu.au.
authors.forename: Justin P
authors.initials: JP
authors.lastname: Turner
authors.forename: Sepehr
authors.initials: S
authors.lastname: Shakib
authors.forename: Nimit
authors.initials: N
authors.lastname: Singhal
authors.forename: Jonathon
authors.initials: J
authors.lastname: Hogan-Doran
authors.forename: Robert
authors.initials: R
authors.lastname: Prowse
authors.forename: Sally
authors.initials: S
authors.lastname: Johns
authors.forename: J Simon
authors.initials: JS
authors.lastname: Bell
mesh_terms: D000203:Activities of Daily Living; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D004347:Drug Interactions; D005260:Female; D016330:Frail Elderly / Q000706:statistics & numerical data*; D015577:Geriatric Assessment; D006801:Humans; D016015:Logistic Models; D008297:Male; D009369:Neoplasms / Q000188:drug therapy / Q000453:epidemiology* / Q000503:physiopathology*; D016017:Odds Ratio; D010146:Pain / Q000188:drug therapy / Q000209:etiology; D019338:Polypharmacy; D015995:Prevalence; D057566:Self Report; D013021:South Australia / Q000453:epidemiology