Recruitment at a church and other enhancements

Recruitment at a church and other enhancements may increase recruitment.


The absolute increase is 1% (95% CI = 0% to 2%)1

How confident are we in the evidence?  
What is GRADE?

LOW CERTAINTY in the evidence (but see 'What we don't know' below)

1 Treweek S, Pitkethly M, Cook J, Fraser C, Mitchell E, Sullivan F, Jackson C, Taskila TK, Gardner H. Strategies to improve recruitment to randomised trials. Cochrane Database of Systematic Reviews 2018, Issue 2.

The practical impact of recruitment at a church and other enhancements

Imagine a trial that needs to recruit 30 participants and initial recruitment is 30% of those approached. This means you'd need to approach 100 people to recruit 30 (see chart below).

No church recruitment
No church recruitment

Now imagine recruiting at a church. The chart below shows the impact of an absolute increase of 1% (95% CI =0% to 2%)1. Recruitment is now 31%, which means our best estimate is that 97 people would need to be approached to recruit 30 of them.

Enclosing a questionnaire
Enclosing a questionnaire
By recruiting at a church (and other enhancements) as opposed to no church recruitment, our best estimate is that you will need to approach 3 fewer participants.

Where has recruitment at a church and other enhancements been tested?


Including church-based recruitment along with other enhancements such as an improved recruitment letter


No church recruitment and standard recruitment letter and other techniques


1 study including a total of 6246 participants

Study 1: Ford 2004

African American men aged 55 to 74 eligible for a prostate, lung and colorectal cancer screening trial.

Trial intervention?
Unclear but recruitment is to cancer screening trials.

Study location?
Community, USA.

What difference?
3.9% of participants randomised to receive a questionnaire were recruited; 2.9% of participants randomised to not get a questionnaire were recruited

Read more about this study here.

What we still don’t know about recruitment at a church and other enhancements

  • The GRADE assessment is low for this intervention because the risk of bias was unclear and there is only a single evaluation. More evaluations in any type of trial are needed.
  • Please get in touch (email if you would like to do an evaluation because we can help with text for ethics etc.

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