Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

BACKGROUND: Randomized controlled trials (RCTs) are widely accepted as being the most efficient way of investigating the efficacy of psychological therapies. However, researchers conducting RCTs commonly report difficulties in recruiting an adequate sample within planned timescales. In an effort to overcome recruitment difficulties, researchers often are forced to expand their recruitment criteria or extend the recruitment phase, thus increasing costs and delaying publication of results. Research investigating the effectiveness of recruitment strategies is limited, and trials often fail to report sufficient details about the recruitment sources and resources utilized. PURPOSE: We examined the efficacy of strategies implemented during the Staying Well after Depression RCT in Oxford to recruit participants with a history of recurrent depression. METHODS: We describe eight recruitment methods utilized and two further sources not initiated by the research team and examine their efficacy in terms of (1) the return, including the number of potential participants who contacted the trial and the number who were randomized into the trial; (2) cost-effectiveness, comprising direct financial cost and manpower for initial contacts and randomized participants; and (3) comparison of sociodemographic characteristics of individuals recruited from different sources. RESULTS: Poster advertising, web-based advertising, and mental health worker referrals were the cheapest methods per randomized participant; however, the ratio of randomized participants to initial contacts differed markedly per source. Advertising online, via posters, and on a local radio station were the most cost-effective recruitment methods for soliciting participants who subsequently were randomized into the trial. Advertising across many sources (saturation) was found to be important. LIMITATIONS: It may not be feasible to employ all the recruitment methods used in this trial to obtain participation from other populations, such as those currently unwell, or in other geographical locations. Recruitment source was unavailable for participants who could not be reached after the initial contact. Thus, it is possible that the efficiency of certain methods of recruitment was poorer than estimated. Efficacy and costs of other recruitment initiatives, such as providing travel expenses to the in-person eligibility assessment and making follow-up telephone calls to candidates who contacted the recruitment team but could not be screened promptly, were not analysed. CONCLUSION: Website advertising resulted in the highest number of randomized participants and was the second cheapest method of recruiting. Future research should evaluate the effectiveness of recruitment strategies for other samples to contribute to a comprehensive base of knowledge for future RCTs.

Original publication




Journal article


Clin Trials

Publication Date





141 - 149


Adult, Advertising as Topic, Cognitive Therapy, Cost-Benefit Analysis, Depressive Disorder, Female, Humans, Internet, Male, Middle Aged, Mindfulness, Patient Selection, Posters as Topic, Randomized Controlled Trials as Topic, Referral and Consultation, Secondary Prevention