Discontinuation of a randomised controlled trial in general practice due to unsuccessful patient recruitment

Background A randomised controlled trial (RCT) in general practice, recruiting incident patients with (sub)acute sciatica, was discontinued because of insufficient recruitment.

Aim To describe factors that influenced the recruitment process and ultimately led to discontinuation of this trial, and to enable others to learn from this experience.

Design & setting A pragmatic RCT was designed to compare two pain medication prescription strategies for treatment of (sub)acute sciatica in general practice. After 1 year of patient recruitment, the trial was prematurely terminated.

Method To analyse the underperforming recruitment, patient information systems of 20 general practices were screened twice a month to search for eligible patients and identify reasons for non-eligibility. Secondly, after study termination, an open question was distributed to the participating GPs for their views on the recruitment process.

Results A total of 116 GPs from 37 general practices collaborated in the trial. Only eight of 234 patients were included after 12 months. The 22 GPs who offered their opinion on the main reasons for unsuccessful recruitment considered that these were the low incidence rate and strict eligibility criteria, a strong patient and/or GP preference, and time constraints.

Conclusion For this RCT, multiple factors were related to recruitment problems but it remains unknown which determinants prevailed. As the research question is unanswered but remains relevant, it is recommended that GPs’ daily practice is taken into account when designing an RCT, a pilot study should be performed for feasibility of recruitment, and GP assistants should be involved at an early stage.