Protocol for the development and validation of a Polypharmacy Assessment Score for potentially problematic polypharmacy

Abstract

Abstract Background An increasing number of people are using multiple medications each day, named polypharmacy. This is driven by an ageing population, increasing multimorbidity, and single disease focussed guidelines. Medications carry obvious benefits, yet problematic polypharmacy is linked to adverse consequences including adverse drug events, drug-drug and drug-disease interactions, poor patient experience and wasted resources. There is a need to improve how we identify and evaluate these patients. Aim To produce a clinically representative PolypharmacyAssessment Score that can be implemented in practice to improve how we identify and evaluate people with potentially problematic polypharmacy Methods Analyses will be performed in three parts: 1. A regression model will explore predictors of polypharmacy and inform the development of a “Polypharmacy Assessment Score”. This will be constructed through calculating the discrepancies between the observed and expected count of prescribed medications, given an individual’s age, gender and clinical diagnoses, thereby highlighting people that have unexpected levels of prescribing and thus identifying potentially problematic polypharmacy. Parts 2 and 3 will examine different aspects of validity of the Polypharmacy Assessment Score: 2. To assess ‘construct validity’ of the score, cross-sectional analyses will evaluate high-risk prescribing (using both explicit and implicit measures of inappropriate prescribing) within populations with a range of different Polypharmacy Assessment Scores 3. To assess ‘predictive validity’ of the score, a retrospective cohort study will explore differences in clinical outcomes (adverse drug reactions, unplanned hospitalisation and all-cause mortality) between differing scores. Discussion Developing a robust and cross-cutting measure of polypharmacy has the potential to empower healthcare professionals to provide more effective and tailored care to patients with complex medication needs and better health outcomes. Our novel approach to producing a Polypharmacy Assessment Score uses unusual levels of prescribing to provide an indication of patients who may be at higher risk of potentially problematic polypharmacy.