Strengths and limitations
Study participants were from 7 out of 8 trial sites. The inclusion of an eighth site might have produced additional findings, however, the sample size of 14 participants from seven sites across England and Wales provided a rich data with reasonable geographic variation across the NHS, although the absence of study sites in Scotland and Northern Ireland may have impacted on future transferability if NHS systems contain features that make a difference to implementation. Healthcare professionals comprised including consultants and ESPs, which was appropriate given the care pathway’s design and delivery. In terms of data collection and analysis, use of NoMAD as a topic framework helped participants to identify and explore in detail issues relevant to implementation. A deductive content analysis provided a way to examine the core constructs of NPT that underpin NoMAD. This is also the first study that we are aware of that has used the NoMAD instrument as a topic framework for interviews to explore in detail issues relevant to implementation.As previously described, some of the participants were known to the team as they were in regular contact with team members about the delivery of the trial. The interviewer had met three participants previously in a training session provided to the participants. Although this could be construed as a potential limiting factor, as social scientists we remained aware of the relationship, and on reflection feel that this was not detrimental to data collection.