“To have, to hold, from this day forward”: understanding current practice regarding the retention of trial participants

Abstract

Findings Clear and cohesive definitions of retention were given. However, there was less agreement about the concept of ‘withdrawal’ from a trial. More experienced trialists emphasised different levels of withdrawal and were happy to negotiate with participants in order to at least collect primary outcome data. Novice trialists presumed the participants wanted to withdraw from all aspects of the trial and made no further contact with them. Research Nurses used their interpersonal skills to motivate participants to remain in their trials. This required time not routinely acknowledged within the funding of trials. Participants described proactive and reactive approaches to retention. Proactive approaches involved anticipated and considered strategies, both formal and informal, to maintain retention. Conversely, reactive approaches were typified by unanticipated and spontaneous strategies, some formalised others informal, developed in response to retention problems during the trial.