Developing a measure of appropriate polypharmacy in primary care: systematic review and RAND appropriateness study.

Problem

Increasing multimorbidity and a culture of single-condition guideline-driven prescribing are important factors contributing to widespread polypharmacy (use of multiple medications in one individual). Polypharmacy may be clinically appropriate, but can also be associated with a range of adverse outcomes. Polypharmacy is usually quantified using simple counts of medication, but there is a need to develop a valid and reliable means of measuring it that can also account for clinical appropriateness. Ideally such a metric should focus on generic prescribing issues to ensure relevance to all patients. This would have value for targeting medication optimisation strategies as well as monitoring effectiveness of interventions. The aim of this study was to identify what experts consider to be key elements of a measure of appropriate prescribing, in the context of polypharmacy.

Approach

A systematic review of nine databases was undertaken to identify potential indicators of appropriate polypharmacy for expert review. We subsequently undertook a two-stage RAND consensus approach with a panel of ten clinical experts. In round one, panel members completed an online survey, rating each indicator in terms of clinical importance and clarity. In round two, each indicator was reviewed and discussed at a face-to-face meeting, prior to panel members individually rating each indicator for clinical importance and feasibility of implementation.

Findings

We identified 20,879 papers for title/abstract screening: of these, 273 papers were obtained in full, and 189 generic indicators extracted. 29 indicators were subsequently identified to be irrelevant, leaving 160 indicators to be presented to the panel. Indicators were grouped into 18 classifications (including, for example, adherence, dosage, or clinical efficacy). We focus here on panel ratings for clinical importance. In the round one online survey, there was consensus between the panel members that 120 indicators were of clinical importance, with six indicators being identified as of potential importance. In the round two face-to-face meeting (during which additional indicators could be introduced by the panel), there was consensus that 140 indicators were of clinical importance, with 19 of potential importance. A further 25 indicators did not gain consensus for clinical importance. Panel members particularly valued indicators concerned with adverse drug reactions, contraindications, interactions, and the conduct of medication reviews. There was a notable lack of prioritisation of, and consensus around, indicators relating to cost-effectiveness.

Consequences

Following the full RAND consensus process, we have identified 140 generic indicators of clinical importance to appropriate polypharmacy prescribing. We are currently operationalising highly rated indicators to develop a measure of appropriate polypharmacy suitable for use in clinical systems and practice. Such a measure will have utility for risk stratification and targeting and monitoring polypharmacy interventions.