Monitoring polypharmacy at the population level entails complex decisions: results of a survey of experts in geriatrics and pharmacotherapy

Aim The use of multiple medications is rising steadily among older individuals, but little is known about the impact of polypharmacy at a population level, both over time and across countries. Surveillance of polypharmacy is required to overcome these gaps. There currently exists no standard population indicator of polypharmacy. The objective of this survey was to query expert opinion on establishing a gold standard method for polypharmacy surveillance at the population level. Methodology We invited 71 experts in geriatrics, pharmacoepidemiology, pharmacology and surveillance to respond to an Internet-based survey. Participants were asked to rate their degree of agreement on statements related to the definition of polypharmacy, the goals of polypharmacy surveillance and knowledge transfer issues. Consensus was reached when 70 % of participants either strongly or moderately agreed with the statements. Qualitative content analysis was performed on optional comments provided by the participants. Results Thirty individuals (42 %) completed the survey. Consensus was reached on most items. However, there was no agreement on a quantitative indicator of polypharmacy. Participants resolved that the indicator include a quality component, and that levels of polypharmacy be created. Defining exposure also proved problematic: cumulative (e.g. total annual number) and/or simultaneous (concomitant) prescriptions could be considered. Conclusions A gold standard indicator of polypharmacy should include both quantity and quality. There is a need to better inform the relevant outcomes of polypharmacy, to identify the most appropriate threshold(s) and quality measure(s) of interest to decision makers.