Impact of a deferred recruitment model in a randomised controlled trial in primary care (CREAM study)

Recruitment of participants is particularly challenging in primary care, with less than a third of randomised controlled trials (RCT) achieving their target within the original time frame. Participant identification, consent, randomisation and data collection can all be time-consuming. Trials recruiting an incident, as opposed to a prevalent, population may be particularly affected. This paper describes the impact of a deferred recruitment model in a RCT of antibiotics for children with infected eczema in primary care, which required the recruitment of cases presenting acutely.

Eligible children were identified by participating general practitioners (GPs) and referred to a study research nurse, who then visited them at home. This allowed the consent and recruitment processes to take place outside the general practice setting. Information was recorded about patients who were referred and recruited, or if not, the reasons for non-recruitment. Data on recruitment challenges were collected through semi-structured interviews and questionnaires with a sample of participating GPs. Data were thematically analysed to identify key themes.

Of the children referred to the study 34% (58/171) were not recruited - 48% (28/58) because of difficulties arranging a baseline visit within the defined time frame, 31% (18/58) did not meet the study inclusion criteria at the time of nurse assessment, and 21% (12/58) declined participation. GPs had positive views about the recruitment process, reporting that parents valued and benefitted from additional contact with a nurse. GPs felt that the deferred recruitment model did not negatively impact on the study.

GPs and parents recognised the benefits of deferred recruitment, but these did not translate into enhanced recruitment of participants. The model resulted in the loss of a third of children who were identified by the GP as eligible, but not subsequently recruited to the study. If the potential for improving outcomes in primary care through complex studies is to be realised, new approaches to recruitment into primary care trials need to be developed and evaluated.

International Standard Randomised Controlled Trials, ISRCTN96705420 . Registered on 27 June 2012.