Process evaluation of the Safer Prescribing and Care for the Elderly (SPACE) cluster randomised controlled trial in New Zealand general practice

Introduction: The Safer Prescribing and Care for the Elderly (SPACE) cluster randomised controlled trial in 39 general practices found that a search of the practice database to identify and generate for each general practitioner (GP) a list of patients with high-risk prescribing, pharmacist-delivered one-on-one feedback to GPs, and electronic tick-box for GPs to select action for each patient (Patient letter; No letter but possible medication review when patient next in; No action), prompted safer prescribing at 6 months but not at 1 year. Aim: This process evaluation explores research participation, intervention uptake and effect on GPs. Methods: Mixed methods were used including quantitative data (log of practice recruitment, demographic data, intervention delivery and GP responses including tick-box selections) and qualitative data (trial pharmacist reflective journal). Data were analysed using descriptive statistics and general inductive analysis, respectively. Results: Recruitment of general practices was challenging, with only 39% of eligible practices agreeing to participate. Those who declined were often ‘too busy’. Engagement was also challenging, especially in larger practices, with the trial pharmacist managing to meet with only 64% of GPs in the intervention group. The GPs who did engage were positive about the intervention, but elected to send letters to only 23% of patients with high-risk prescribing, either because the high-risk prescribing had already stopped, the GP did not agree the prescribing was ‘high-risk’ or the GP was concerned a letter would upset the patient. Conclusions: Effectiveness of the SPACE cluster randomised controlled trial could be improved by changes including ensuring searches are current and relevant, repeating cycles of search and feedback, and integrating pharmacists into general practices.