Example

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“Participants are recruited internally within the community-based FQHC [federally qualified health center]. The clinic data team regularly creates, updates, and shares a list of potentially eligible patients based on their recent HIV [human immunodeficiency virus] care history with the research team. Clinic staff also help to recruit from their patient population by reviewing clinic schedules weekly to identify participants with a pending appointment who might qualify based on the eligibility criteria for on-site recruitment. Other clinic staff, such as case managers and general medical staff, are informed of study details and eligibility to provide preliminary study information and refer potential participants. Research staff also work with other teams within the HIV Department to promote the study. The clinic’s community advisory board also serves as a resource for informing potential participants that the study is occurring, and study participants can also refer friends” [308].

 

“Evidence-based site selection was used to confirm the eligibility of each centre to participate in the trial using volumes of endovascular repair of infra-renal and thoraco-abdominal aortic aneurysms listed on the National Vascular Registry as well as a record of satisfactory patient outcomes and strong clinical engagement. During the trial, the team will maintain regular contact with the sites, undertake regular site visits, and ensure there are adequate numbers of randomisers at sites and that Cydar EV is installed in as many rooms as required. These will be supplemented by in person local principal investigator and research nurse meetings where site teams can hear the experience of other sites and problems and tips and tricks to ensure strong participant recruitment can be shared ”[309].

Explanation

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The main goal of recruitment is to meet the target sample size (Item 19). However, recruitment difficulties are common in clinical trials [310, 311]. For example, a review of trials from 2004 to 2016 funded by the United Kingdom’s Health Technology Assessment Programme found that 44% did not reach their recruitment targets [312]. Inadequate enrolment will reduce statistical power and can lead to early trial stoppage or to extensions with delayed results and greater costs.

Strategies to promote adequate enrolment are thus important to consider during trial planning. Recruitment strategies can vary depending on the trial topic, context, and site. Different recruitment methods can substantially affect the number and type of trial participants recruited [207, 310, 313, 314], and can incur different costs [315-317]. Design issues such as the number and stringency of eligibility criteria will also directly affect the number of eligible trial participants.

 

While most trials will use strategies to promote enrolment of participants, this information is often incompletely reported in trial protocols [9, 10, 318]. For example, reviews of two samples of 108 and 292 trial protocols from 2016 found that less than 44% of protocols reported the location of recruitment, persons who will recruit, or expected recruitment rate [9, 10].

 

Protocol descriptions of where participants will be recruited (e.g., primary care clinic, community), by whom (e.g., surgeon), when (e.g., time after diagnosis), and how (e.g., advertisements, review of health records) can be helpful for assessing the feasibility of achieving the target sample size and the applicability of the trial results in practice. Other relevant information to explicitly provide in the protocol includes expected recruitment rates, duration of the recruitment period, plans to monitor recruitment during the trial, and any financial or non-financial incentives provided to trial investigators (Item 3a) or participants for enrolment.

 

Summary of key elements to address

• Planned strategies to promote adequate enrolment (e.g., advertisements, pre-screening of health records, reducing participant burden)

• Where participants will be recruited (e.g., primary care clinic, community), by whom (e.g., surgeon), and when (e.g., time period after diagnosis)