Trial reportBMJ (Clinical research ed.)2005
Recruiting patients to medical research: double blind randomised trial of "opt-in" versus "opt-out" strategies.
Trial report in BMJ (Clinical research ed.), 2005. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 108 papers, 4 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
108 citing papers in PubMed, 4 syntheses or guidelines pooled it.
- Methods to increase response to postal and electronic questionnaires.The Cochrane database of systematic reviews · 2023Pooled it
- Strategies to improve recruitment to randomised trials.The Cochrane database of systematic reviews · 2018Pooled it
- Methods to increase response to postal and electronic questionnaires.The Cochrane database of systematic reviews · 2009Pooled it
- [External validity of clinical trials for treatment of dementia with ginkgo biloba extracts].Zeitschrift fur Gerontologie und Geriatrie · 2008Pooled it
- Parent and practitioner experiences of opt-out consent in neonatal intensive care: a mixed methods study within a trial.Archives of disease in childhood. Fetal and neonatal edition · 2026Trial
- Trial
- Trial
- Trial
- Challenges of a simplified opt-out consent process in a neonatal randomised controlled trial: qualitative study of parents' and health professionals' views and experiences.Archives of disease in childhood. Fetal and neonatal edition · 2021Trial
- Implementation fidelity in a complex intervention promoting psychosocial well-being following stroke: an explanatory sequential mixed methods study.BMC medical research methodology · 2019Trial
- Barriers to Recruitment in Pediatric Obesity Trials: Comparing Opt-in and Opt-out Recruitment Approaches.Journal of pediatric psychology · 2017Trial
- Cluster randomized trial assessing the effects of rapid ethical assessment on informed consent comprehension in a low-resource setting.BMC medical ethics · 2016Trial
- Trial
- Impact of Risk Assessment and Tailored versus Nontailored Risk Information on Colorectal Cancer Testing in Primary Care: A Randomized Controlled Trial.Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology · 2015Trial
- Trial
- The PRCI study: design of a randomized clinical trial to evaluate a coping intervention for medical waiting periods used by women undergoing a fertility treatment.BMC women's health · 2013Trial
- Trial
- Participant recruitment in sensitive surveys: a comparative trial of 'opt in' versus 'opt out' approaches.BMC medical research methodology · 2013Trial
- Trial
- Identifying strategies to maximise recruitment and retention of practices and patients in a multicentre randomised controlled trial of an intervention to optimise secondary prevention for coronary heart disease in primary care.BMC medical research methodology · 2009Trial
48 more citing papers are in PubMed but not listed here.
Corrections and comments
- Commented on by
Authors and funding
5 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectiveTo evaluate the effect of opt-in compared with opt-out recruitment strategies on response rate and selection bias.
designDouble blind randomised controlled trial.
settingTwo general practices in England.
participants510 patients with angina.
interventionPatients were randomly allocated to an opt-in (asked to actively signal willingness to participate in research) or opt-out (contacted repeatedly unless they signalled unwillingness to participate) approach for recruitment to an observational prognostic study of patients with angina.
main outcome measuresRecruitment rate and clinical characteristics of patients.
resultsThe recruitment rate, defined by clinic attendance, was 38% (96/252) in the opt-in arm and 50% (128/258) in the opt-out arm (P = 0.014). Once an appointment had been made, non-attendance at the clinic was similar (20% opt-in arm v 17% opt-out arm; P = 0.86). Patients in the opt-in arm had fewer risk factors (44% v 60%; P = 0.053), less treatment for angina (69% v 82%; P = 0.010), and less functional impairment (9% v 20%; P = 0.023) than patients in the opt-out arm.
conclusionsThe opt-in approach to participant recruitment, increasingly required by ethics committees, resulted in lower response rates and a biased sample. We propose that the opt-out approach should be the default recruitment strategy for studies with low risk to participants.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.