Prevalence and factors associated with polypharmacy in older people with cancer

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.

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).