Comparing potentially inappropriate prescribing tools and their association with patient outcomes.

Objective: To assess the agreement of several different measures of potentially inappropriate prescribing (PIP) in older people and compare their relationship with patient-reported outcomes.

Design: Prospective cohort study including participants in The Irish Longitudinal Study on Ageing (TILDA).

Setting: Waves 1 and 2 of TILDA, a nationally representative aging cohort study.

Participants: A total of 1753 community-dwelling TILDA participants with linked administrative pharmacy claims data on medications.

Measurements: Potentially inappropriate medications were assessed using the Screening Tool of Older Persons' Potentially Inappropriate Prescriptions (STOPP) v1, American Geriatrics Society (AGS) Beers Criteria® 2012, and relevant Assessing Care of Vulnerable Elders (ACOVE) v3 indicators. Potential prescribing omissions were assessed using the Screening Tool to Alert Doctors to the Right Treatment (START) v1 and ACOVE v3 indicators. Their agreement was assessed via κ statistics, and multivariate regression was used to assess relationships with emergency department visits, general practitioner (GP) visits, quality of life, and functional decline (increased assistance needed for activities of daily living).

Results: There was slight agreement between STOPP and AGS Beers Criteria® (κ = 0.20) and ACOVE indicators (κ = 0.15), while agreement between AGS Beers Criteria® and ACOVE indicators was fair (κ = 0.31). Agreement was fair between START and ACOVE indicators (κ = 0.34). All measures of inappropriate medications were significantly associated with increased GP visits. Only exposure to two or more START indicators was associated with reduced quality of life (adjusted mean difference = -1.12; 95% confidence interval [CI] = -1.92 to -0.33), and only two or more AGS Beers Criteria® were associated with functional decline (adjusted odds ratio = 2.11; 95% CI = 1.37-3.28). For omissions, both measures were associated with functional decline, but only ACOVE indicators were associated with increased GP visits.

Conclusion: Prevalence of PIP and relationships with outcomes can differ substantially between tools with little agreement. Choice of PIP measure for research or practice should be considered in light of the circumstances and requirements in each case.