Relationship between frailty, polypharmacy, and underprescription in older adults living in nursing homes

Frailty, polypharmacy, and underprescription are considered a major matter of concern in nursing homes, but the possible relationships between them are not well known. The aim is to examine the possible association between medication underprescription, polypharmacy, and frailty in older people living in nursing homes. A cross-sectional analysis from a concurrent cohort study, including 110 subjects 65 years living in two nursing homes. Four frailty scales were applied; polypharmacy was defined as 5 medications and underprescription was measured with Screening Tool to Alert to Right Treatment (START) criteria. Logistic regression models were performed to assess the associations. The mean age was 86.3 years (SD 7.3) and 71.8% were female. 73.6% of subjects took 5 chronic medications and 60.9% met one or more START criteria. The non-frail participants took more medications than the frail subjects according to the imputated frailty Fried criteria (8.1 vs 6.7, p = 0.042) and the FRAIL-NH scale (7.8 vs 6.8, p = 0.026). Multivariate analyses did not find an association between frailty and polypharmacy. Frail participants according to the Fried criteria met a higher number of START criteria (1.9 vs 1.0, p = 0.017), and had a higher prevalence of underprescription (87.5 vs 50.0%), reaching the limit of statistical significance in multivariate analysis. The positive association found in previous studies between frailty and polypharmacy cannot be extrapolated to institutionalized populations. There is a trend towards higher rates of underprescription in frail subjects. Underprescription in frail older adults should be redefined and new strategies to measure it should be developed.