ArticleBMJ (Clinical research ed.)2014
Subgroup analyses in randomised controlled trials: cohort study on trial protocols and journal publications.
Article in BMJ (Clinical research ed.), 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. Cited by 53 papers, 6 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
53 citing papers in PubMed, 6 syntheses or guidelines pooled it.
- What works for whom: a systematic review of inequalities in inclusion and effectiveness of social interventions for mental ill- health.Social psychiatry and psychiatric epidemiology · 2026Pooled it
- Effect Modification Analyses in Individual Participant Data Meta-Analyses: A Systematic Review.JAMA network open · 2026Pooled it
- Estimating the prevalence of discrepancies between study registrations and publications: a systematic review and meta-analyses.BMJ open · 2023Pooled it
- A systematic review of comparisons between protocols or registrations and full reports in primary biomedical research.BMC medical research methodology · 2018Pooled it
- Pooled it
- Sex based subgroup differences in randomized controlled trials: empirical evidence from Cochrane meta-analyses.BMJ (Clinical research ed.) · 2016Pooled it
- Effectiveness of a behavioural intervention delivered by text messages (safetxt) on sexually transmitted reinfections in people aged 16-24 years: randomised controlled trial.BMJ (Clinical research ed.) · 2022Trial
- Surgical fixation compared with cast immobilisation for adults with a bicortical fracture of the scaphoid waist: the SWIFFT RCT.Health technology assessment (Winchester, England) · 2020Trial
- An Intervention Delivered by Mobile Phone Instant Messaging to Increase Acceptability and Use of Effective Contraception Among Young Women in Bolivia: Randomized Controlled Trial.Journal of medical Internet research · 2020Trial
- A randomized controlled trial of an intervention delivered by mobile phone app instant messaging to increase the acceptability of effective contraception among young people in Tajikistan.Reproductive health · 2018Trial
- Trial
- Trial
- Patient characteristics associated with greater blood pressure control in a randomized trial of home blood pressure telemonitoring and pharmacist management.Journal of the American Society of Hypertension : JASH · 2016Trial
- Who Benefits from Family Psychoeducation for Relatives of Adults with Major Depressive Disorder? Findings from a Randomized Controlled Trial.Journal of clinical medicine · 2026Article
- Common reporting errors in subgroup analysis: a comparison of interaction and stratified regression models.BMC medical research methodology · 2026Article
- Association between ambulatory blood pressure monitoring parameters and left ventricular hypertrophy in an Ecuadorian population.Frontiers in medicine · 2026Article
- HPV genotype-specific p16/Ki67 expression with machine learning-assisted assessment in cervical neoplasia.Frontiers in oncology · 2026Article
- Equity of participants in clinical trials in critical care and perioperative medicine research: a systematic review.BJA open · 2025Review
- Article
- Description of subgroup reporting in clinical trials of chronic diseases: a meta-epidemiological study.BMJ open · 2024Article
Corrections and comments
- Erratum issuedKasenda, Benjamin [added]; Schandelmaier, Stefan [added]; Sun, Xin [added]; von Elm, Erik [added]; You, John [added]; Blümle, Anette [added]; Tomonaga, Yuki (8) Saccilotto, Ramon (9) Amstutz, Alain [added]; Bengough, Theresa [added]; etc.
Authors and funding
40 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectiveTo investigate the planning of subgroup analyses in protocols of randomised controlled trials and the agreement with corresponding full journal publications.
designCohort of protocols of randomised controlled trial and subsequent full journal publications.
settingSix research ethics committees in Switzerland, Germany, and Canada. DATA SOURCES: 894 protocols of randomised controlled trial involving patients approved by participating research ethics committees between 2000 and 2003 and 515 subsequent full journal publications.
resultsOf 894 protocols of randomised controlled trials, 252 (28.2%) included one or more planned subgroup analyses. Of those, 17 (6.7%) provided a clear hypothesis for at least one subgroup analysis, 10 (4.0%) anticipated the direction of a subgroup effect, and 87 (34.5%) planned a statistical test for interaction. Industry sponsored trials more often planned subgroup analyses compared with investigator sponsored trials (195/551 (35.4%) v 57/343 (16.6%), P<0.001). Of 515 identified journal publications, 246 (47.8%) reported at least one subgroup analysis. In 81 (32.9%) of the 246 publications reporting subgroup analyses, authors stated that subgroup analyses were prespecified, but this was not supported by 28 (34.6%) corresponding protocols. In 86 publications, authors claimed a subgroup effect, but only 36 (41.9%) corresponding protocols reported a planned subgroup analysis.
conclusionsSubgroup analyses are insufficiently described in the protocols of randomised controlled trials submitted to research ethics committees, and investigators rarely specify the anticipated direction of subgroup effects. More than one third of statements in publications of randomised controlled trials about subgroup prespecification had no documentation in the corresponding protocols. Definitive judgments regarding credibility of claimed subgroup effects are not possible without access to protocols and analysis plans of randomised controlled trials.
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.