Using qualitative research methods to improve recruitment to randomized controlled trials: the Quartet study

Randomized controlled trials (RCTs) are considered the optimum method for evaluating health care interventions, yet many fail to recruit sufficient participants in a timely manner. The ProtecT (Prostate testing for cancer and Treatment) study employed qualitative research methods as part of a complex intervention to improve recruitment to the RCT. The Quartet (Qualitative research to improve recruitment to trials) study was set up to evalute whether the ProtecT study's success in increasing randomization rates could be replicated in other trials experiencing recruitment difficulties. This paper reports on the issues that emerged from the attempts to apply qualitative research methods to improve recruitment rates in RCTs collaborating with the Quartet team.

The methods used were: investigation of RCT documents; semi-structured interviews and focus groups with RCT staff; audio-recording of recruitment appointments; and individual and group feedback sessions for RCT staff. Data were analysed using content and thematic analysis.

Barriers arose when we attempted to establish collaborations with RCTs. Difficulties were encountered in securing the commitment of all relevant staff because of poor communication between lead investigators and other staff as well as RCT staff's concerns about having recruitment appointments audio-recorded. Recruitment processes were often more complex than anticipated. Governance procedures took considerable time and resources, limiting the time available for data collection and implementation of the intervention before recruitment closure.

Straightforward replication of the ProtecT complex intervention was more complicated than expected. However, the study has increased understanding of RCT recruitment and identified ways to overcome barriers to collaboration. Such research is more easily undertaken in the feasibility stage of an RCT, and greater success will be achieved if the research is integrated into the everyday conduct of RCTs.