Background: Researchers sometimes undertake qualitative research with randomised controlled trials (RCTs) of health interventions.
Objectives: To systematically explore how qualitative research is being used with trials and identify ways of maximising its value to the trial aim of providing evidence of effectiveness of health interventions.
Design: A sequential mixed methods study with four components.
Methods: (1) Database search of peer-reviewed journals between January 2008 and September 2010 for articles reporting the qualitative research undertaken with specific trials, (2) systematic search of database of registered trials to identify studies combining qualitative research and trials, (3) survey of 200 lead investigators of trials with no apparent qualitative research and (4) semistructured telephone interviews with 18 researchers purposively sampled from the first three methods.
Results: Qualitative research was undertaken with at least 12% of trials. A large number of articles reporting qualitative research undertaken with trials (n=296) were published between 2008 and 2010. A total of 28% (82/296) of articles reported qualitative research undertaken at the pre-trial stage and around one-quarter concerned drugs or devices. The articles focused on 22 aspects of the trial within five broad categories. Some focused on more than one aspect of the trial, totalling 356 examples. The qualitative research focused on the intervention being trialled (71%, 254/356), the design and conduct of the trial (15%, 54/356), the outcomes of the trial (1%, 5/356), the measures used in the trial (3%, 10/356), and the health condition in the trial (9%, 33/356). The potential value of the qualitative research to the trial endeavour included improving the external validity of trials and facilitating interpretation of trial findings. This value could be maximised by using qualitative research more at the pre-trial stage and reporting findings with explicit attention to the implications for the trial endeavour. During interviews, three models of study were identified: qualitative research as peripheral to the trial, qualitative research as an 'add-on' to the trial and a study with qualitative research and trial as essential components, with the third model offering more opportunity to maximise the value of the qualitative research. Interviewees valued the use of qualitative research with trials and identified team structures and wider structural issues which gave more value to the trial than the qualitative research as barriers to maximising the value of the qualitative research.
Conclusion: A large number of articles were published between 2008 and 2010, addressing a wide range of aspects of trials. There were examples of this research affecting the trial by facilitating interpretation of trial findings, developing and refining interventions for testing in the trial and changing the measures used in the trial. However, researchers were not necessarily maximising the value of qualitative research undertaken with trials to the endeavour of generating evidence of effectiveness of health interventions. Researchers can maximise value by promoting its use at the pre-trial stage to ensure that the intervention and trial conduct is optimised at the main trial stage, being explicit about the conclusions for the trial endeavour in peer-reviewed journal articles reporting the qualitative research and valuing the contribution of the qualitative research as much as the trial. Future recommendations for researchers include: plan the qualitative research, design and implement studies not trials, use qualitative research at the feasibility and pilot stage of trials, be explicit in publications about the impact of the qualitative research on the trial and implications for the trial endeavour, undertake in-depth qualitative research, allow qualitative research to take a challenging role and develop a learning environment around the use of qualitative research and trials.
Funding: This project was funded by the Medical Research Council (MRC) as part of the MRC-National Institute for Health Research Methodology Research programme.