Potentially inappropriate prescribing according to STOPP and START and adverse outcomes in community-dwelling older people: a prospective cohort study.

AIMS: This study aims to determine if potentially inappropriate prescribing (PIP) is associated with increased healthcare utilization, functional decline and reduced quality of life (QoL) in a community-dwelling older cohort.

METHOD: This prospective cohort study included participants aged ≥65 years from The Irish Longitudinal Study on Ageing (TILDA) with linked administrative pharmacy claims data who were followed up after 2 years. PIP was defined by the Screening Tool for Older Persons Prescriptions (STOPP) and Screening Tool to Alert doctors to Right Treatment (START). The association with number of emergency department (ED) visits and GP visits reported over 12 months was analyzed using multivariate negative binomial regression adjusting for confounders. Marginal structural models investigated the presence of time-dependent confounding.

RESULTS: Of participants followed up (n = 1753), PIP was detected in 57% by STOPP and 41.8% by START, 21.7% reported an ED visit and 96.1% visited a GP (median 4, IQR 2.5-6). Those with any STOPP criterion had higher rates of ED visits (adjusted incident rate ratio (IRR) 1.30, 95% confidence interval (CI) 1.02, 1.66) and GP visits (IRR 1.15, 95%CI 1.06, 1.24). Patients with two or more START criteria had significantly more ED visits (IRR 1.45, 95%CI 1.03, 2.04) and GP visits (IRR 1.13, 95%CI 1.01, 1.27) than people with no criteria. Adjusting for time-dependent confounding did not affect the findings.

CONCLUSIONS: Both STOPP and START were independently associated with increased healthcare utilization and START was also related to functional decline and QoL. Optimizing prescribing to reduce PIP may provide an improvement in patient outcomes.