The DOI matches its Crossref record; 111 of the 113 references it cites were found in a registry or an index.
Blinding in randomised clinical trials of psychological interventions: a retrospective study of published trial reports
Abstract
Objectives: To study the extent of blinding in randomised clinical trials of psychological interventions and the interpretative considerations if randomised clinical trials are not blinded. Design: Retrospective study of trial reports published in six high impact factor journals within the field of psychiatry in 2017 and 2018. Setting: Trial reports published in World Psychiatry , JAMA Psychiatry , Lancet Psychiatry , American Journal of Psychiatry , British Journal of Psychiatry , or Psychotherapy and Psychosomatics . Main outcome measures: Blinding status of participants, treatment providers, outcome assessors, data managers, the data safety and monitoring committee, statisticians and conclusion makers, if trialists rejected the null hypothesis on the primary outcome measure, and if trialists discussed the potential bias risk from lack of blinding in the published trial report. Results: 63 randomised clinical trials of psychological interventions were identified. None (0%; 95% CI 0% to 5.75%) of the trials reported blinding of all possible key persons. 37 (58.7%; 95% CI 46.42% to 70.04%) trials reported blinding of outcome assessors. Two (3.2%; 95% CI 0.87% to 10.86%) trials reported blinding of participants. Two (3.2%; 95% CI 0.87% to 10.86%) trials reported blinding of data managers. Three (4.8%; 95% CI 1.63% to 13.09%) trials reported blinding of statisticians. None of the trials reported blinding of treatment providers, the data safety and monitoring committee, and conclusion makers. 45 (71.4%; 95% CI 59.30% to 81.10%) trials rejected the null hypothesis on the primary outcome(s). 13 (20.7%; 95% CI 12.48% to 32.17%) trials discussed the potential bias risk from lack of blinding in the published trial report. Conclusions: Blinding of key persons involved in randomised clinical trials of psychological interventions is rarely sufficiently documented. The possible interpretative limitations are only rarely considered. There is a need of randomised clinical trials of psychological interventions with documented blinding attempts of all possible key persons.
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In the citing paper
“These approaches overlap with those reported in previous studies [8, 14, 18, 19, 23] and reflect the many considerations required to ensure blinding of outcome assessors.”
From Blinding outcome assessors in randomised controlled trials of psychological interventions: how is it done? A narrative review (2026) · cites this paper as [14]
In the citing paper
“Previous studies have frequently reported replacing outcome assessors in the event they become unblinded [14, 19], an approach that was frequently reported in studies in the present review.”
From Blinding outcome assessors in randomised controlled trials of psychological interventions: how is it done? A narrative review (2026) · cites this paper as [14]
In the citing paper
“This is despite this practice being considered problematic, as such assessments cannot distinguish between blinding efficacy and outcome assessors’ hunches about the efficacy and harms of the intervention [14, 21].”
From Blinding outcome assessors in randomised controlled trials of psychological interventions: how is it done? A narrative review (2026) · cites this paper as [14]
In the citing paper
“Similar to the earlier review by Juul and colleagues [14], a substantial proportion (39%) of studies in the present study did not provide sufficient detail on how blinding was managed in practice.”
From Blinding outcome assessors in randomised controlled trials of psychological interventions: how is it done? A narrative review (2026) · cites this paper as [14]
In the citing paper
“The most common method reported was avoiding unblinding by participants through asking them not to discuss their treatment, a method frequently reported in the existing literature [5, 14, 18, 23].”
From Blinding outcome assessors in randomised controlled trials of psychological interventions: how is it done? A narrative review (2026) · cites this paper as [14]
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Research works printed but not linked: 1
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Hohenschurz‐Schmidt, D., Vase, L., Scott, W., Annoni, M., Ajayi, O. K., Barth, J., Bennell, K. L., Berna, C., Bialosky, J. E., BRAITHWAITE, F., et al. (2023) · BMJ · doi:10.1136/bmj-2022-072108 · Cited by 110
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Metadata
- Authors
- Juul, S., Gluud, C., Simonsen, S., Frandsen, F. W., Kirsch, I., & Jakobsen, J. C.
- Affiliations
- Mental Health Services (DK)
- Copenhagen University Hospital (DK)
- Harvard University (US)
- University of Southern Denmark (DK)
- Corresponding author
- Juul, Sophie
- ORCID
- Venue
- BMJ Evidence-Based Medicine
- Publisher
- BMJ
- Published
- 2020-09-30
- Volume
- 26
- Issue
- 3
- Pages
- 109-109
- ISSN
- 1356-5524 (ISSN-L)
- 2515-446X
- 2515-4478
- OpenAlex
- W3091014787
- Semantic Scholar
- d3805f0a7094ac1f67a6cd4cf28729cf664779c8
- Cited by
- 135
- References
- 113
- Citations by year
- 2026: 21 · 2025: 28 · 2024: 47 · 2023: 22 · 2022: 12 · 2021: 5
- FWCI
- 5.95
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- BMJ Evidence-Based Medicine (publishedVersion)
- PubMed (publishedVersion)
- University of Southern Denmark Research Portal (University of Southern Denmark) (publishedVersion)
- Topics
- Social Sciences › Decision Sciences › Statistics, Probability and Uncertainty › Meta-analysis and systematic reviews
- Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods in Clinical Trials
- Social Sciences › Psychology › Clinical Psychology › Psychotherapy Techniques and Applications
- Keywords
- blinding, randomized controlled trials, psychological intervention, risk of bias, null hypothesis rejection
- MeSH terms
- Humans, Retrospective Studies, Randomized Controlled Trials as Topic, Research Report
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