Placebo interventions for all clinical conditions

Hróbjartsson, Asbjørn; Gøtzsche, Peter C

doi:10.1002/14651858.cd003974.pub2

Cited by 300 publications

(434 citation statements)

References 298 publications

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“…This is consistent with evidence that sham therapy alone can reduce a continuous outcome by between 0.2 and 0.5 standard deviations, 55 possibly due to therapeutic effects of the relationship between the participant and the treatment provider. Figure 5 Summary of primary meta-analyses, of adverse events and loss to follow-up: estimated overall risk difference between relaxation and control groups.…”

Section: Summary Of Findingssupporting

confidence: 89%

Relaxation therapies for the management of primary hypertension in adults: a Cochrane review

et al. 2008

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The objective of this review was to evaluate the effectiveness of relaxation to lower high blood pressure. We searched electronic bibliographic databases and grey literature to identify randomized controlled trials comparing relaxation therapies with no active treatment or sham therapy, enrolling adult participants with raised systolic blood pressure (SBP) X140 mm Hg or diastolic blood pressure (DBP) X85 mm Hg and follow-up X8 weeks. Twenty-five trials with up to 5 years follow-up, assessing 1198 participants, met our inclusion criteria and were metaanalysed. Overall, relaxation resulted in small, statistically significant reductions in SBP (mean difference: À5.5 mm Hg, 95% CI: À8.2 to À2.8) and DBP (mean difference: À3.5 mm Hg, 95% CI: À5.3 to À1.6) compared to the control. Substantial heterogeneity between trials (I 2 470%) was not explained by duration of follow-up, type of control, type of relaxation therapy or baseline blood pressure. The 9 trials that reported blinding of outcome assessors found a nonsignificant net reduction in blood pressure (SBP mean difference: À3.2 mm Hg, 95% CI: À7.7 to 1.4) associated with relaxation, as did the 15 trials comparing relaxation with sham therapy (SBP mean difference: À3.5 mm Hg, 95% CI: À7.1 to 0.2). Adequate randomization was confirmed in only seven trials and concealment of allocation in only one. In view of the poor quality of the included trials and unexplained variation between trials, the evidence in favour of a causal association between relaxation and blood pressure reduction is weak. Some of the apparent benefit of relaxation was probably due to aspects of treatment unrelated to relaxation.

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Section: Summary Of Findingssupporting

confidence: 89%

Relaxation therapies for the management of primary hypertension in adults: a Cochrane review

et al. 2008

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“…The use of an appropriate control group was found to improve the reliability of acupuncture studies (26). However, selecting an ideal control group for acupuncture research is a challenging methodological issue (27).…”

Section: Problems With Study Designmentioning

confidence: 99%

Is acupuncture no more than a placebo? Extensive discussion required about possible bias

Deng

Zhao

et al. 2015

Experimental and Therapeutic Medicine

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Abstract. Numerous randomized controlled trials (RCTs) of acupuncture have been conducted in recent years. The results of several studies implied that acupuncture was only a powerful placebo; however, certain studies demonstrated that verum acupuncture had a greater effect than placebo and the mechanisms between a verum acupuncture group and a placebo/sham group were different. Researchers attempted to investigate the inherent factors that may potentially influence the results of trials. Certain problems observed in acupuncture RCTs also occurred in RCTs in other fields, including insufficient sample size, high dropout rates, inadequate follow-up and randomization. The study of acupuncture is so complex that specific methodological challenges are raised, which are frequently overlooked, including sham interventions, blinding, powerful placebo effects (even stronger than an inert pill) and variations in acupuncture administration. The aforementioned problems may contribute to bias, and researchers systematically attempt to solve these problems. The present review aimed to suggest techniques to design high-quality studies, minimize the placebo effect and optimize acupuncture administration in acupuncture studies. If these problems are addressed, then the results of acupuncture studies may be different.

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“…[53] The time has come to use similar methods to investigate ways to rationalize placebo use. The long term viability of placebo use in clinical practice depends on whether placebo benefits outweigh harms, [54] their cost, and whether patients and practitioners deem their use to be ethically acceptable. Further investigations are warranted to develop ethical and cost-effective placebos.…”

Section: Implications For Future Research and Clinical Practicementioning

confidence: 99%

Placebo use in the United Kingdom: results from a national survey of primary care practitioners

2013

Br Dent J

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Objectives: Surveys in various countries suggest 17% to 80% of doctors prescribe 'placebos' in routine practice, but prevalence of placebo use in UK primary care is unknown. Methods:We administered a web-based questionnaire to a representative sample of UK general practitioners. Following surveys conducted in other countries we divided placebos into 'pure' and 'impure'. 'Impure' placebos are interventions with clear efficacy for certain conditions but are prescribed for ailments where their efficacy is unknown, such as antibiotics for suspected viral infections. 'Pure' placebos are interventions such as sugar pills or saline injections without direct pharmacologically active ingredients for the condition being treated. We initiated the survey in April 2012. Two reminders were sent and electronic data collection closed after 4 weeks. Results:We surveyed 1715 general practitioners and 783 (46%) completed our questionnaire. Our respondents were similar to those of all registered UK doctors suggesting our results are generalizable. 12% (95% CI 10 to 15) of respondents used pure placebos while 97% (95% CI 96 to 98) used impure placebos at least once in their career. 1% of respondents used pure placebos, and 77% (95% CI 74 to 79) used impure placebos at least once per week. Most (66% for pure, 84% for impure) respondents stated placebos were ethical in some circumstances. Conclusion and implications:Placebo use is common in primary care but questions remain about their benefits, harms, costs, and whether they can be delivered ethically. Further research is required to investigate ethically acceptable and costeffective placebo interventions.

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Placebo interventions for all clinical conditions

Abstract: There was no evidence that placebo interventions in general have clinically important effects. A possible small effect on continuous patient-reported outcomes, especially pain, could not be clearly distinguished from bias.

Cited by 300 publications

References 298 publications

Relaxation therapies for the management of primary hypertension in adults: a Cochrane review

Relaxation therapies for the management of primary hypertension in adults: a Cochrane review

Is acupuncture no more than a placebo? Extensive discussion required about possible bias

Placebo use in the United Kingdom: results from a national survey of primary care practitioners

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