Improving Medicines use in People with Polypharmacy in Primary Care (IMPPP): Delivery of a multicentre cluster randomised trial evaluating a complex intervention for medication optimisation
Problem
Polypharmacy is increasingly common, and associated with undesirable consequences. Polypharmacy management necessitates balancing therapeutic benefits and risks, and varying clinical and patient priorities. Current guidance for managing polypharmacy is not supported by high quality evidence. The aim of the Improving Medicines use in People with Polypharmacy in Primary Care (IMPPP) trial is to evaluate the effectiveness of an intervention to optimise medication use for patients with polypharmacy in a general practice setting.
Approach
The IMPPP trial is a multicentre, open-label, cluster-randomised trial, with two parallel groups. Practices have been randomised to a complex intervention comprising structured medication review (including interprofessional GP/pharmacist treatment planning and patient-facing review) supported by performance feedback, financial incentivisation, clinician training and a bespoke clinical informatic tool (intervention), or usual care (control). Patients with multiple medications (5+) and triggering at least one potentially inappropriate prescribing (PIP) indicator have been recruited in each practice using a computerised search of health records, aiming for 50 patients per practice. The intervention is being delivered over a 26-week period. The primary outcome is mean number of PIP indicators triggered per patient at 26 weeks follow-up, determined objectively from coded GP electronic health records. Secondary outcomes include patient reported outcome measures, and health and care service use. A nested process evaluation is exploring implementation of the intervention.
Findings
The study is ongoing, with intervention delivery expected to end by April 2023. 37 practices (19 intervention) have been recruited from the South-West and West Midlands regions. Median list size is 10800 (range 4650-49000), with median practice deprivation decile of 6 (range 2 (more deprived) to 10). Median percentage of patients meeting inclusion criteria was 7.3% (range 3.2%-12.1%) across practices. Of these, a total of 1956 patients consented (median acceptance rate 21%, range 11%-30%). The informatics tool has been successfully rolled out across all practices. In intervention practices, initial clinical training and regular practice feedback have been implemented. Practices in the intervention arm have been able to successfully meet delivery targets for the intervention; in general over 80% of recruited patients have received completed reviews to date, and over 90% in those practices that have completed the intervention delivery period.
Consequences
The IMPPP trial has demonstrated that it is possible to implement and evaluate a complex intervention for patient-centred medication optimisation for polypharmacy within primary care, with good engagement by GPs, pharmacists and patients. We will report provisional findings on baseline population characteristics and completed intervention delivery. The study is highly relevant to current primary care practice and policy, with the potential to inform improved delivery of medication optimisation for people experiencing polypharmacy.