Process evaluation of the Data-driven Quality Improvement in Primary Care (DQIP) trial:case-study evaluation of adoption and maintenance of a complex intervention to reduce high-risk primary care prescribing

Objective: Explore how different practices responded to the Data driven quality improvement in primary care (DQIP) intervention in terms of their adoption of the work, reorganisation to deliver the intended change in care to patients, and whether implementation was sustained over time.Design: Mixed methods parallel process evaluation of a cluster trial, reporting the comparative case study of purposively selected practices.Setting: Ten (30%) primary care practices participating in the trial. Scotland, United Kingdom.Results: Four practices were sampled because they had large rapid reductions in targeted prescribing. They all had internal agreement that the topic mattered, made early plans to implement including assigning responsibility for work, and regularly evaluated progress. However, how they internally organised the work varied. Six practices were sampled because they had initial implementation failure. Implementation failure occurred at different stages depending on practice context, including internal disagreement about whether the work was worthwhile, and intention but lack of capacity to implement or sustain implementation due to unfilled posts or sickness. Practice context was not fixed, and most practices with initial failed implementation adapted to deliver at least some elements. All interviewed participants valued the intervention because it was an innovative way to address on an important aspect of safety (although one of the non-interviewed GPs in one practice disagreed with this). Participants felt that reviewing existing prescribing did influence their future initiation of targeted drugs, but raised concerns about sustainability.Conclusions: Variation in implementation and effectiveness was associated with differences in how practices valued, engaged with, and sustained the work required. Initial implementation failure varied with practice context, but was not static, with most practices at least partially implementing by the end of the trial. Practices organised their delivery of changed care to patients in ways which suited their context, emphasising the importance of flexibility in any future widespread implementation.Trial registration: ClinicalTrials.gov number, NCT0142550