Recruitment to, and Reduction of Attrition from Randomised Controlled Trials

Randomised controlled trials (RCTs) are viewed as the "gold standard" approach to evaluating health care interventions (e.g. drugs, technology etc). However if not enough people take part the results can be equivocal and may not be useful. In extreme cases the trial may have to finish early. We also know that when people who take part in a trial drop out (attrition) this can compromise the validity of the findings.There has been research about what factors influence recruitment to RCTs, however there remains a need for systematic evaluation of effective strategies to improve recruitment. More recent technological innovations such as web based recruitment and mobile technology have the potential to effect both recruitment and attrition. Attrition from RCTs has received less attention.We aim to 1) Conduct two systematic reviews:a) effective interventions to reduce attritionb) effective recruitment strategies from 2005-20083) Interview people who conduct trials about strategies to improve recruitment and reduce attrition4) Identify data on recruitment strategies in RCTs and reduction of attrition, in recently completed trials, which have not been analysed or published5) Organise a national workshop to disseminate findings.

Randomised controlled trials (RCTs) are viewed as the "gold standard" approach for evaluating interventions and minimising bias. Failure to recruit adequate numbers of participants can lead to equivocal results or premature termination of the trial. Attrition, whereby patients are lost to follow-up (e.g. cannot be contacted, refuse to participate further), can seriously compromise the validity of RCT findings.

A body of literature exists regarding what factors influence recruitment to RCTs, and also which strategies may be effective in improving recruitment. However there remains a need for identifying solutions employed in current RCTs and systematic evaluation of effective strategies to improve recruitment. More recent technological innovations such as web based recruitment and mobile technology have the potential to effect both recruitment and attrition. Attrition from RCTs has received less attention. The reasons for attrition in cohort studies and RCTs may differ. For example, randomisation may result in participants being allocated to an arm of the trial that they did not want to be in.

The purpose of the cross unit appointment would be to:
1) Conduct a systematic review of effective interventions to reduce attrition within RCTs
2) Update the current systematic review on effective recruitment strategies from 2005-2008
3) Interview trialists about their views on successful strategies to improve recruitment and reduce attrition in RCTs
4) Identify through the MRC units if there are data on recruitment strategies in RCTs and reduction of attrition, in recently completed trials, which have not been analysed or published
5) Organise a national workshop at the end of 24 months to disseminate findings and agree strategies to further develop the research in this field