To identify the effect of a complex intervention (educational outreach visits by pharmacists) designed to change general practitioners' (GPs') prescribing on each step of a hypothesised pathway of change leading to the final primary trial outcome of change in prescribing.
The study was undertaken in six health authorities in the North of England and six in London. We described three steps leading to this outcome: the general practices agreeing to participate; GPs in each practice attending the outreach visit conducted by the pharmacists; and the GPs' prescribing practice being influenced by these visits. The outcomes of each step were assessed using a combination of quantitative and qualitative methods.
Of the 102 practices randomly selected, 75 (73.5%) agreed to participate. The odds of all the doctors attending the outreach meeting in small practices (i.e. 1-2 partners) was 6.7 (95% CI: 4.4-23.5) compared with other practices (i.e. > 3 partners). Although the pharmacists reported that they had established a good rapport at 100 (72%) first visits and had agreed management plans for 110 (79%) of these visits, they were confident that the practice was likely to alter its prescribing in only 41% of these visits. Pharmacists' and GPs' satisfaction with the outreach visits did not necessarily lead to prescribing changes after the practice visit, and the GPs' knowledge of the guidelines promoted by the pharmacists did not necessarily translate into changes in clinical practice. The main barriers to the implementation of guidelines identified by the pharmacists at the follow-up visits were organisational difficulties, the GPs' scepticism of the evidence presented to them and the doctors' lack of interest in changing their prescribing behaviour.
Although our study is limited by a post hoc rather than a pre hoc design, it provides a pragmatic approach to understanding the factors influencing the pathway of change in prescribing behaviour in response to academic outreach visits.