Article type
Year
Abstract
Background: Design and reporting standards for control interventions in randomised clinical trials with mental health populations are lacking, and methodological guidelines are needed in this area to improve evidence-based practice.
Objectives: To assess the beneficial and harmful effects and adverse events of different placebos (psychological, pharmacological, and physical), usual care, and wait-list control interventions in randomised trials with mental health disorders.
Methods: In March 2018 we searched MEDLINE, PsycInfo, Embase, CENTRAL, and seven other databases, and six trials registers. Randomised clinical trials comparing placebos, usual care or wait-list intervention versus either wait-list or no-treatment were eligible. Participants at any age and setting were required to have a mental health disorder. We included outcomes on beneficial effects of all included mental health disorders combined and specific disorders as well as outcomes on non-serious and serious adverse events. Three review authors independently selected trials, extracted data, assessed risk of bias using Cochrane's 'Risk of bias' tool and graded the certainty of the evidence with GRADE. We performed data analysis using Review Manager 5 and quantified the statistical reliability of the data using Trial Sequential Analysis.
Results: We included 94 parallel-arm, one cluster-randomised, and one cross-over trial with a total of 4,198 (individual trial range 8 to 393) participants, ranged from eight to 393 participants in each trial. Only 70 trials provided usable data for our analyses. 46 trials used a psychological placebo, 23 trials used a pharmacological placebo, and 17 trials used a physical placebo as a control intervention. Nine trials included a usual care control intervention, while only one trial included both a wait-list and a no-treatment control intervention. Participants ages ranged from 2.85 to 86.5 mean years. More than 15 different mental health diagnoses were included.
All 96 trials were assessed to be at high risk of bias. The certainty of evidence was rated low to very low.
All three placebo types combined versus wait list or no intervention showed a significant low to moderate beneficial effect across all included mental health disorders (give SMD and 95% CI). Similar results were found for psychological and physical placebos separately, but we found no significant effects on pharmacological placebos and neither for usual care. No differences in serious adverse events were found. Subgroup analyses revealed a significant group difference between trials compared with wait-list in relation to trials compared with no-treatment for placebo interventions combined.
Conclusions: We found some indications that placebo treatment might be beneficial for mental health disorders, with low to very low quality of evidence. Methodological guidelines are needed on reporting standards and research design of control interventions in randomised trials with mental health populations.
Patient or healthcare consumer involvement: None
Objectives: To assess the beneficial and harmful effects and adverse events of different placebos (psychological, pharmacological, and physical), usual care, and wait-list control interventions in randomised trials with mental health disorders.
Methods: In March 2018 we searched MEDLINE, PsycInfo, Embase, CENTRAL, and seven other databases, and six trials registers. Randomised clinical trials comparing placebos, usual care or wait-list intervention versus either wait-list or no-treatment were eligible. Participants at any age and setting were required to have a mental health disorder. We included outcomes on beneficial effects of all included mental health disorders combined and specific disorders as well as outcomes on non-serious and serious adverse events. Three review authors independently selected trials, extracted data, assessed risk of bias using Cochrane's 'Risk of bias' tool and graded the certainty of the evidence with GRADE. We performed data analysis using Review Manager 5 and quantified the statistical reliability of the data using Trial Sequential Analysis.
Results: We included 94 parallel-arm, one cluster-randomised, and one cross-over trial with a total of 4,198 (individual trial range 8 to 393) participants, ranged from eight to 393 participants in each trial. Only 70 trials provided usable data for our analyses. 46 trials used a psychological placebo, 23 trials used a pharmacological placebo, and 17 trials used a physical placebo as a control intervention. Nine trials included a usual care control intervention, while only one trial included both a wait-list and a no-treatment control intervention. Participants ages ranged from 2.85 to 86.5 mean years. More than 15 different mental health diagnoses were included.
All 96 trials were assessed to be at high risk of bias. The certainty of evidence was rated low to very low.
All three placebo types combined versus wait list or no intervention showed a significant low to moderate beneficial effect across all included mental health disorders (give SMD and 95% CI). Similar results were found for psychological and physical placebos separately, but we found no significant effects on pharmacological placebos and neither for usual care. No differences in serious adverse events were found. Subgroup analyses revealed a significant group difference between trials compared with wait-list in relation to trials compared with no-treatment for placebo interventions combined.
Conclusions: We found some indications that placebo treatment might be beneficial for mental health disorders, with low to very low quality of evidence. Methodological guidelines are needed on reporting standards and research design of control interventions in randomised trials with mental health populations.
Patient or healthcare consumer involvement: None