SynthesisBMJ open2015
Placebo effects in trials evaluating 12 selected minimally invasive interventions: a systematic review and meta-analysis.
Synthesis in BMJ open, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 20 papers, 3 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
20 citing papers in PubMed, 3 syntheses or guidelines pooled it.
- Use of Placebo and Nonoperative Control Groups in Surgical Trials: A Systematic Review and Meta-analysis.JAMA network open · 2022Pooled it
- Pooled it
- Feasibility of surgical randomised controlled trials with a placebo arm: a systematic review.BMJ open · 2016Pooled it
- Trial
- Safety and efficacy of occipital nerve stimulation as treatment of chronic cluster headache: an investigator-initiated, double-blind, randomized, placebo-controlled study.The journal of headache and pain · 2026Trial
- Watermelon and dietary advice compared to dietary advice alone following hospitalization for hyperemesis gravidarum: a randomized controlled trial.BMC pregnancy and childbirth · 2023Trial
- KALK study: ultrasound guided needling and lavage (barbotage) with steroid injection versus sham barbotage with and without steroid injection - protocol for a randomized, double-blinded, controlled, multicenter study.BMC musculoskeletal disorders · 2017Trial
- Magnitude of the placebo response across non-surgical treatment modalities used for knee osteoarthritis: A meta-analysis with meta-regression.Osteoarthritis and cartilage open · 2026Review
- Neurobehavioral symptom changes following bilateral two-level stellate ganglion blocks in patients with traumatic brain injury: a retrospective analysis of 102 patients.Frontiers in neuroscience · 2026Article
- Three-Month Durability of Bilateral Two-Level Stellate Ganglion Blocks for Traumatic Brain Injury: A Retrospective Analysis.Biomedicines · 2025Article
- International web-based survey of patients with non-hydrocephalic symptomatic pineal cysts.Acta neurochirurgica · 2024Article
- "A second birthday"? Experiences of persons with multiple sclerosis treated with autologous hematopoietic stem cell transplantation-a qualitative interview study.Frontiers in neurology · 2024Article
- Ethics of Early Clinical Trials of Bio-Artificial Organs.Transplant international : official journal of the European Society for Organ Transplantation · 2022Article
- The American Society of Pain and Neuroscience (ASPN) Practical Guidelines to Study Design and Scientific Manuscript Preparation in Neuromodulation.Journal of pain research · 2021Review
- Impact of percutaneous patent foramen ovale closure on migraine headaches in patients with history of ischemic neurological events.Postepy w kardiologii interwencyjnej = Advances in interventional cardiology · 2020Article
- Pain, placebo, and test of treatment efficacy: a narrative review.British journal of anaesthesia · 2019Review
- Cell therapy for intervertebral disc herniation and degenerative disc disease: clinical trials.International orthopaedics · 2019Review
- Evidence-Based Evaluation of the Ethics of Sham Surgery for Parkinson's Disease.Journal of Parkinson's disease · 2019Article
- Miscommunication in Doctor-Patient Communication.Topics in cognitive science · 2018Article
- Randomised placebo-controlled trials of surgery: ethical analysis and guidelines.Journal of medical ethics · 2016Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
3 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectivesTo analyse the impact of placebo effects on outcome in trials of selected minimally invasive procedures and to assess reported adverse events in both trial arms.
designA systematic review and meta-analysis. DATA SOURCES AND STUDY SELECTION: We searched MEDLINE and Cochrane library to identify systematic reviews of musculoskeletal, neurological and cardiac conditions published between January 2009 and January 2014 comparing selected minimally invasive with placebo (sham) procedures. We searched MEDLINE for additional randomised controlled trials published between January 2000 and January 2014. DATA SYNTHESIS: Effect sizes (ES) in the active and placebo arms in the trials' primary and pooled secondary end points were calculated. Linear regression was used to analyse the association between end points in the active and sham groups. Reported adverse events in both trial arms were registered.
resultsWe included 21 trials involving 2519 adult participants. For primary end points, there was a large clinical effect (ES≥0.8) after active treatment in 12 trials and after sham procedures in 11 trials. For secondary end points, 7 and 5 trials showed a large clinical effect. Three trials showed a moderate difference in ES between active treatment and sham on primary end points (ES ≥0.5) but no trials reported a large difference. No trials showed large or moderate differences in ES on pooled secondary end points. Regression analysis of end points in active treatment and sham arms estimated an R(2) of 0.78 for primary and 0.84 for secondary end points. Adverse events after sham were in most cases minor and of short duration.
conclusionsThe generally small differences in ES between active treatment and sham suggest that non-specific mechanisms, including placebo, are major predictors of the observed effects. Adverse events related to sham procedures were mainly minor and short-lived. Ethical arguments frequently raised against sham-controlled trials were generally not substantiated.
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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.