SynthesisBMJ (Clinical research ed.)2015
Deviation from intention to treat analysis in randomised trials and treatment effect estimates: meta-epidemiological study.
Synthesis in BMJ (Clinical research ed.), 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 74 papers, 24 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
74 citing papers in PubMed, 24 syntheses or guidelines pooled it.
- Impact of Different Dosage Forms of Orally Administered Chinese Herbal Medicine on Treatment and Adverse Effect Estimates in Randomized Controlled Trials: A Meta-Epidemiological Study.Journal of evidence-based medicine · 2026Pooled it
- Antenatal Physical Activity Interventions and Pregnancy Outcomes: A Systematic Review and Meta-Analysis With a Focus on Trial Quality.BJOG : an international journal of obstetrics and gynaecology · 2025Pooled it
- Effects and safety of transcranial direct current stimulation on multiple health outcomes: an umbrella review of randomized clinical trials.Molecular psychiatry · 2024Pooled it
- Interventions for the prevention or treatment of epidural-related maternal fever: a systematic review and meta-analysis.British journal of anaesthesia · 2022Pooled it
- Does vaginal progesterone prevent recurrent preterm birth in women with a singleton gestation and a history of spontaneous preterm birth? Evidence from a systematic review and meta-analysis.American journal of obstetrics and gynecology · 2022Pooled it
- Pooled it
- Effects of isoflavone interventions on bone mineral density in postmenopausal women: a systematic review and meta-analysis of randomized controlled trials.Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA · 2020Pooled it
- Simulated presence therapy for dementia.The Cochrane database of systematic reviews · 2020Pooled it
- Shortened treatment regimens versus the standard regimen for drug-sensitive pulmonary tuberculosis.The Cochrane database of systematic reviews · 2019Pooled it
- Preoperative radiotherapy and curative surgery for the management of localised rectal carcinoma.The Cochrane database of systematic reviews · 2018Pooled it
- Pooled it
- The effectiveness of virtual reality based interventions for symptoms of anxiety and depression: A meta-analysis.Scientific reports · 2018Pooled it
- Pooled it
- Laparoscopic versus open resection for sigmoid diverticulitis.The Cochrane database of systematic reviews · 2017Pooled it
- Exercise interventions for cerebral palsy.The Cochrane database of systematic reviews · 2017Pooled it
- Simulated presence therapy for dementia.The Cochrane database of systematic reviews · 2017Pooled it
- Pooled it
- A systematic analysis of controlled clinical trials using the NiTi CAR™ compression ring in colorectal anastomoses.Techniques in coloproctology · 2017Pooled it
- Laparoscopic lavage versus surgical resection for acute diverticulitis with generalised peritonitis: a systematic review and meta-analysis.Techniques in coloproctology · 2017Pooled it
- Methodological quality of behavioural weight loss studies: a systematic review.Obesity reviews : an official journal of the International Association for the Study of Obesity · 2016Pooled it
14 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
12 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectiveTo examine whether deviation from the standard intention to treat analysis has an influence on treatment effect estimates of randomised trials.
designMeta-epidemiological study. DATA SOURCES: Medline, via PubMed, searched between 2006 and 2010; 43 systematic reviews of interventions and 310 randomised trials were included. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: From each year searched, random selection of 5% of intervention reviews with a meta-analysis that included at least one trial that deviated from the standard intention to treat approach. Basic characteristics of the systematic reviews and randomised trials were extracted. Information on the reporting of intention to treat analysis, outcome data, risk of bias items, post-randomisation exclusions, and funding were extracted from each trial. Trials were classified as: ITT (reporting the standard intention to treat approach), mITT (reporting a deviation from the standard approach), and no ITT (reporting no approach). Within each meta-analysis, treatment effects were compared between mITT and ITT trials, and between mITT and no ITT trials. The ratio of odds ratios was calculated (value <1 indicated larger treatment effects in mITT trials than in other trial categories).
results50 meta-analyses and 322 comparisons of randomised trials (from 84 ITT trials, 118 mITT trials, and 108 no ITT trials; 12 trials contributed twice to the analysis) were examined. Compared with ITT trials, mITT trials showed a larger intervention effect (pooled ratio of odds ratios 0.83 (95% confidence interval 0.71 to 0.96), P=0.01; between meta-analyses variance τ(2)=0.13). Adjustments for sample size, type of centre, funding, items of risk of bias, post-randomisation exclusions, and variance of log odds ratio yielded consistent results (0.80 (0.69 to 0.94), P=0.005; τ(2)=0.08). After exclusion of five influential studies, results remained consistent (0.85 (0.75 to 0.98); τ(2)=0.08). The comparison between mITT trials and no ITT trials showed no statistical difference between the two groups (adjusted ratio of odds ratios 0.92 (0.70 to 1.23); τ(2)=0.57).
conclusionsTrials that deviated from the intention to treat analysis showed larger intervention effects than trials that reported the standard approach. Where an intention to treat analysis is impossible to perform, authors should clearly report who is included in the analysis and attempt to perform multiple imputations.
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.