Evidence map›Paper›PMID 28701195›Full record

SynthesisTrials2017

A meta-analysis of temporal changes of response in the placebo arm of surgical randomized controlled trials: an update.

Karolina A Wartolowska, Stephen Gerry, Benjamin G Feakins, Gary S Collins, Jonathan Cook, Andrew Judge, Andrew J Carr

Registry-linked trialAbstract readMeta-AnalysisSystematic Review
PubMed Full text at PMC Publisher
In one paragraph

Synthesis in Trials, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT06666621 (Antagonism of Endogenous Opioids), which is not on this map. Cited by 16 papers, 4 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
16citing papers in PubMed, 4 pooled it
–field-weighted citation impact
1 · What the graph read from 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.

2 · The registry

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.

NCT06666621 phase4recruitingnot on this mapstarted 2024, after this paper: background citation

Antagonism of Endogenous Opioids: Use in Interpretation of Injections

TypeinterventionalSponsorMiddle Tennessee Research InstituteRan2024 to 2026Enrolled33ConditionsLow Back Pain, Zygapophyseal Joint ArthritisArmsNormal saline infusion, Naloxone infusion
3 · Its place in the literature

Who cites it

16 citing papers in PubMed, 4 syntheses or guidelines pooled it.

  1. Pooled it
  2. Pooled it
  3. Pooled it
  4. Pooled it
  5. Trial
  6. Trial
  7. Contextual effects: how to, and how not to, quantify them.BMC medical research methodology · 2024
    Review
  8. Article
  9. Article
  10. Article
  11. Review
  12. Article
  13. Review
  14. Review
  15. Article
  16. Bronchial thermoplasty-an update.Annals of thoracic medicine
    Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors.

Karolina A WartolowskaNIHR Oxford Musculoskeletal Biomedical Research Unit, Old Road, OX3 7LD, Oxford, UK. karolina.wartolowska@ndorms.ox.ac.uk.
Stephen GerryBotnar Institute of Musculoskeletal Sciences, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Old Road, OX3 7LD, Oxford, UK.
Benjamin G FeakinsNuffield Department of Primary Care Health Sciences, University of Oxford, Woodstock Road, OX2 6GG, Oxford, UK.
Gary S CollinsBotnar Institute of Musculoskeletal Sciences, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Old Road, OX3 7LD, Oxford, UK.
Jonathan CookNIHR Oxford Musculoskeletal Biomedical Research Unit, Old Road, OX3 7LD, Oxford, UK.
Andrew JudgeNIHR Oxford Musculoskeletal Biomedical Research Unit, Old Road, OX3 7LD, Oxford, UK.
Andrew J CarrNIHR Oxford Musculoskeletal Biomedical Research Unit, Old Road, OX3 7LD, Oxford, UK.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundTemporal changes in the placebo arm of randomized controlled trials (RCTs) have not been thoroughly investigated, despite the fact that results of RCTs depend on the comparison between arms.

methodsIn this update of our earlier systematic review and meta-analysis, we set out to investigate the effect of assessment time and number of visits on the magnitude of change from baseline in the placebo arm of these trials. We used linear mixed-effects models to account for within-trial correlations.

resultsAcross all 47 trials the magnitude of response in the placebo arm did not change with time (β = -0.0070, 95% CI -0.024, 0.010) or visit (β = -0.033, 95% CI -0.082, 0.017) and remained significantly different from baseline for at least 12 months or seven follow-up visits. Change in the placebo arm in trials with subjective outcomes was large (β

conclusionsThese results are consistent with our previous findings. In trials with subjective outcomes response in the placebo arm remains large and relatively constant for at least a year, which is interesting considering that this is an effect of a single application of an invasive procedure. The lack of effect of time and visit number on subjective outcomes raises further questions regarding whether the observed response is the result of placebo effect or the result of bias.

Indexed as

Placebo EffectHumansRandomized Controlled Trials as TopicResearch DesignTime FactorsTreatment OutcomeMeta-analysisPlacebosRandomized controlled trialsSurgerySystematic review

Identifiers

PMID28701195
PMCPMC5508709

What OpenQuestion holds

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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.