SynthesisBMJ evidence-based medicine2023
Proportion attributable to contextual effects in general medicine: a meta-epidemiological study based on Cochrane reviews.
Synthesis in BMJ evidence-based medicine, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT06361472 (A Two-Center, Investigator-Blinded, Randomized, 4-Week, Parallel-Group, Superiority Study Comparing Contextual Factors-Enriched Standard Care Versus Standard Care Only for Patients With Mechanical Neck Pain), which is not on this map. Cited by 6 papers, 2 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.
A Two-Center, Investigator-Blinded, Randomized, 4-Week, Parallel-Group, Superiority Study Comparing Contextual Factors-Enriched Standard Care Versus Standard Care Only for Patients With Mechanical Neck Pain (ContextualizAR Trial)
Who cites it
6 citing papers in PubMed, 2 syntheses or guidelines pooled it, 16 citations in OpenAlex.
- Contextual effects of mesenchymal stem cell injections for knee osteoarthritis: systematic review and meta-analysis of randomized controlled trials.Frontiers in medicine · 2025Pooled it
- The impact of contextual effects in exercise therapy for low back pain: a systematic review and meta-analysis.BMC medicine · 2024Pooled it
- Article
- "The Dark Side of Musculoskeletal Care": Why Do Ineffective Techniques Seem to Work? A Comprehensive Review of Complementary and Alternative Therapies.Biomedicines · 2025Review
- Not "that kind" of doctor: an exploratory study on Doctor of Physical Therapy-patient introductions in the United States.The Journal of manual & manipulative therapy · 2024Article
- The Biology of Placebo and Nocebo Effects on Experimental and Chronic Pain: State of the Art.Journal of clinical medicine · 2023Review
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 at 6 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectivesOur objectives were to examine the magnitude of the proportion attributable to contextual effects (PCE), which shows what proportion of the treatment arm response can be achieved by the placebo arm across various interventions, and to examine PCE variability by outcome type and condition.
designWe conducted a meta-epidemiological study.
settingWe searched the Cochrane Database of Systematic Reviews with the keyword 'placebo' in titles, abstracts and keywords on 1 January 2020.
participantsWe included reviews that showed statistically significant beneficial effects of the intervention over placebo for the first primary outcome.
main outcome measuresWe performed a random-effects meta-analysis to calculate PCEs based on the pooled result of each included review, grouped by outcome type and condition. The PCE quantifies how much of the observed treatment response can be achieved by the contextual effects. PUBLIC AND PATIENT INVOLVEMENT STATEMENT: No patient or member of the public was involved in conducting this research.
resultsWe included 328 out of 3175 Cochrane systematic reviews. The results of meta-analyses showed that PCEs varied greatly depending on outcome type (I
conclusionsThe results suggest that much of the observed benefit is not just due to the specific effect of the interventions. The specific effects of interventions may be larger for subjective outcomes than for objective or semiobjective outcomes. However, PCEs were exceptionally variable. When we evaluate the magnitude of PCEs, we should consider each PCE individually, for each condition, intervention and outcome in its context, to assess the importance of an intervention for each specific clinical setting.
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.