ArticleJournal of medical ethics2017
What trial participants need to be told about placebo effects to give informed consent: a survey to establish existing knowledge among patients with back pain.
Article in Journal of medical ethics, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 12 papers, 1 of them a synthesis 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
12 citing papers in PubMed, 1 synthesis or guideline pooled it.
- Measuring and evaluating participant understanding of consent processes in clinical trials: a systematic review.Trials · 2026Pooled it
- Informing Adults With Back Pain About Placebo Effects: Randomized Controlled Evaluation of a New Website With Potential to Improve Informed Consent in Clinical Research.Journal of medical Internet research · 2019Trial
- Transforming patient recruitment in clinical trials: Communication training to manage uncertainties about risks and benefits.Journal of clinical and translational science · 2026Article
- Tensions Within Incentives, Altruism, and Trust in Clinical Trial Participation: Perspectives From African American and Black Caribbean Patients and Clinical Research Coordinators Who Recruit Them.Journal of racial and ethnic health disparities · 2025Article
- Justice for Placebo: Placebo Effect in Clinical Trials and Everyday Practice.Medicines (Basel, Switzerland) · 2025Review
- Lessons learned from examination of Canadian medico-legal cases related to interventional therapies for chronic pain management.Canadian journal of anaesthesia = Journal canadien d'anesthesie · 2023Article
- Article
- Can an Open-Label Placebo Be as Effective as a Deceptive Placebo? Methodological Considerations of a Study Protocol.Medicines (Basel, Switzerland) · 2020Article
- The Knowledge of Contextual Factors as Triggers of Placebo and Nocebo Effects in Patients With Musculoskeletal Pain: Findings From a National Survey.Frontiers in psychiatry · 2019Article
- Feasibility and acceptability of a proposed trial of acupuncture as an adjunct to lifestyle interventions for weight loss in Polycystic Ovary Syndrome: a qualitative study.BMC complementary and alternative medicine · 2018Article
- Factors associated with clinical trials that fail and opportunities for improving the likelihood of success: A review.Contemporary clinical trials communications · 2018Review
- Clinical relevance of contextual factors as triggers of placebo and nocebo effects in musculoskeletal pain.BMC musculoskeletal disorders · 2018Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors.
Funding
Abstract
introductionPatients require an accurate knowledge about placebos and their possible effects to ensure consent for placebo-controlled clinical trials is adequately informed. However, few previous studies have explored patients' baseline (ie, pretrial recruitment) levels of understanding and knowledge about placebos. The present online survey aimed to assess knowledge about placebos among patients with a history of back pain.
designA 15-item questionnaire was constructed to measure knowledge about placebos. Additional questions assessed sociodemographic characteristics, duration and severity of back pain, and previous experience of receiving placebos.
settingParticipants recruited from community settings completed the study online.
results210 participants completed the questionnaire. 86.7% had back pain in the past 6 months, 44.3% currently had back pain. 4.3% had received a placebo intervention as part of a clinical trial and 68.1% had previously read or heard information about placebos. Overall knowledge of placebos was high, with participants on average answering 12.07 of 15 questions about placebos correctly (SD=2.35). However, few participants correctly answered questions about the nocebo effect (31.9% correct) and the impact of the colour of a placebo pill (55.2% correct).
conclusionsThe findings identified key gaps in knowledge about placebos. The lack of understanding of the nocebo effect in particular has implications for the informed consent of trial participants. Research ethics committees and investigators should prioritise amending informed consent procedures to incorporate the fact that participants in the placebo arm might experience adverse side effects.
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.