Jacques, R.M. orcid.org/0000-0001-6710-5403, Ahmed, R., Harper, J. et al. (4 more authors) (2022) Recruitment, consent and retention of participants in randomised controlled trials : a review of trials published in the National Institute for Health Research (NIHR) Journals Library (1997–2020). BMJ Open, 12 (2). e059230.
Abstract
Objectives
To review the consent, recruitment and retention rates for randomised controlled trials (RCTs) funded by the UK’s National Institute for Health Research (NIHR) and published in the online NIHR Journals Library between January 1997 and December 2020.
Design
Comprehensive review.
Setting
RCTs funded by the NIHR and published in the NIHR Journals Library.
Data extraction
Information relating to the trial characteristics, sample size, recruitment and retention.
Primary and secondary outcome measures
The primary outcome was the recruitment rate (number of participants recruited per centre per month). Secondary outcomes were the target sample size and whether it was achieved; consent rates (percentage of eligible participants who consented and were randomised) and retention rates (percentage of randomised participants retained and assessed with valid primary outcome data).
Results
This review identified 388 individual RCTs from 379 reports in the NIHR Journals Library. The final recruitment target sample size was achieved in 63% (245/388) of the RCTs. The original recruitment target was revised in 30% (118/388) of trials (downwards in 67% (79/118)). The median recruitment rate (participants per centre per month) was found to be 0.95 (IQR: 0.42–2.60); the median consent rate was 72% (IQR: 50%–88%) and the median retention rate was estimated at 88% (IQR: 80%–97%).
Conclusions
There is considerable variation in the consent, recruitment and retention rates in publicly funded RCTs. Although the majority of (6 out of 10) trials in this review achieved their final target sample; 3 out of 10 trials revised their original target sample size (downwards in 7 out of 10 trials). Investigators should bear this in mind at the planning stage of their study and not be overly optimistic about their recruitment projections.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2022 The Author(s) (or their employer(s)). This is an open access article distributed in accordance with the Creative Commons Attribution 4.0 Unported (CC BY 4.0) license, which permits others to copy, redistribute, remix, transform and build upon this work for any purpose, provided the original work is properly cited, a link to the licence is given, and indication of whether changes were made. See: https://creativecommons.org/licenses/by/4.0/. |
Dates: |
|
Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Medicine, Dentistry and Health (Sheffield) > School of Health and Related Research (Sheffield) > ScHARR - Sheffield Centre for Health and Related Research |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 15 Feb 2022 09:08 |
Last Modified: | 16 Feb 2022 09:36 |
Status: | Published |
Publisher: | BMJ Publishing Group |
Refereed: | Yes |
Identification Number: | 10.1136/bmjopen-2021-059230 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:183616 |