SynthesisClinical and translational gastroenterology2020
Impact of Clinical Outcome Measures on Placebo Response Rates in Clinical Trials for Chronic Constipation: A Systematic Review and Meta-analysis.
Synthesis in Clinical and translational gastroenterology, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 5 papers, 1 of them a synthesis that pooled it.
What it found
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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
5 citing papers in PubMed, 1 synthesis or guideline pooled it.
- Efficacy and Safety of Probiotics, Prebiotics and Synbiotics for the Treatment of Functional Constipation in Children: Systematic Review and Network Meta-analysis.Probiotics and antimicrobial proteins · 2026Pooled it
- A Heat-Inactivated Two-StrainNutrients · 2026Trial
- Early Therapeutic Response Predicts Outcome in Chronic Constipation: A Multicenter Prospective Observational Study.Gastroenterology research · 2026Article
- Efficacy and acceptability of different probiotic products plus laxatives for pediatric functional constipation: a network meta-analysis of randomized controlled trials.European journal of pediatrics · 2024Article
- Contextual effects: how to, and how not to, quantify them.BMC medical research methodology · 2024Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
4 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectivesChronic constipation (CC) is a recurrent functional bowel disorder worldwide. The purpose of this study is to examine its pooled placebo response rate and compare placebo response level in randomized controlled trials (RCTs) with different endpoint assessments.
methodsPubMed, Cochrane Library, and Embase were electronically searched for therapeutic RCTs of CC with placebo control. Data extraction and assessment of risk of bias were performed independently by 2 reviewers. All the statistical calculation and analysis were performed using R 3.6.0. Our protocol has registered in PROSPERO with registration number: CRD42019121287.
resultsThere were 46 studies included with 5,992 constipated patients allocated to the placebo arm in total. The pooled placebo response rate was 28.75% (95% confidence interval: 23.83%-33.67%) with significant heterogeneity among trials ((Equation is included in full-text article.)= 93.6%). Treatment efficacy assessed using subjective improvement had a significantly higher placebo response rate than that assessed with improvement in complete (spontaneous) bowel movements or composite improvement (41.40% vs 18.31% or 20.35%, P < 0.001). According to the results of meta-regression, active treatment and endpoint assessment were most likely to lead to the huge heterogeneity among studies. DISCUSSION: Patients with CC have significant response level to placebo. Based on findings in this study, we do not recommend subjective improvement as endpoint while designing therapeutic RCTs for chronic constipated patients.
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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.