Payment to healthcare professionals for patient recruitment to trials: a systematic review.

Establishing the clinical and cost effectiveness of interventions in healthcare largely depends on good quality randomised controlled trials (RCTs). One element of quality in RCTs is the recruitment of sufficient participants to test a priori hypotheses with statistical confidence and to minimise bias. However, many RCTs fail to meet their recruitment targets. One strategy to increase recruitment to trials is to pay healthcare professionals to recruit subjects either by providing financial incentives or by reimbursing excess costs incurred. Many pharmaceutical companies provide inducements but this is not common practice in publicly funded research programmes. Such programmes need to have confidence that payments are worthwhile. We did a systematic review, therefore, to synthesise the evidence on the effectiveness of payment to healthcare professionals for patient recruitment to trials.