Randomised controlled trials are integral for evidenced based clinical decision making. Within the context of clinical trials, the focus of much methodological research has been on issues relating to trial recruitment. Issues around retention (i.e. ensuring that trial participants remain in the trial to provide primary outcome data) have not received equal scrutiny in the literature despite being arguably just as important for trials in terms of ensuring that research questions are adequately answered.

The aim of this study was to undertake a meta-ethnographic synthesis of findings from primary qualitative studies that explored factors influencing non-retention within a clinical trial context.


We identified 8 qualitative studies (reporting data from 9 trials). Emergent from our synthesis was the significance of trial non-retainers’ perceptions around the personal ‘fit’ of key aspects of the trial with their pre-existing beliefs or life circumstances. These beliefs or circumstances related to their own health state, preferences for how they wanted to receive care, their individual capabilities, beliefs about or experiences of side effects, and also considerations around the extent to which trial participation could be appropriately accommodated (or not) into their broader lives.

If trialists want to improve retention then they should focus on attempts to reduce trial burden, both in terms of the intervention itself and also the ways that follow up data is collected. Providing more detail on the nature of the trial interventions at the consenting stage would prove helpful in order to manage expectations and some early and meaningful patient/public involvement could be particularly important for ensuring that aspects of the trial are user-friendly and as compatible as possible with the target population’s likely preferences and capabilities.


Katie Gillies; 
Zoe Skea; 
Rumana Newlands;