rvallee
Senior Member (Voting Rights)
A Systematic Review and Meta-analysis
Key Points
Question What is the placebo effect magnitude in different treatment modalities used for management of patients with treatment-resistant depression?
Findings In this systematic review and meta-analysis of 3228 patients with treatment-resistant depression in 50 randomized clinical trials, the placebo effect size was large and consistent across treatment modalities. Response and remission rates associated with placebo effect were comparable across modalities.
Meaning The findings of this study suggest a placebo effect size benchmark may be used to interpret the findings of past and future clinical trials.
Results Fifty RCTs were included involving various types of placebo or sham interventions with a total of 3228 participants (mean [SD] age, 45.8 [6.0] years; 1769 [54.8%] female). The pooled placebo effect size for all modalities was large (g = 1.05; 95% CI, 0.91-1.1); the placebo effect size in RCTs of specific treatment modalities did not significantly differ. Similarly, response and remission rates associated with placebo were comparable across modalities. Heterogeneity was large. Three variables were associated with a larger placebo effect size: open-label prospective treatment before double-blind placebo randomization (β = 0.35; 95% CI, 0.11 to 0.59; P = .004), later year of publication (β = 0.03; 95% CI, 0.003 to 0.05; P = .03), and industry-sponsored trials (β = 0.34; 95% CI, 0.09 to 0.58; P = .007). The number of failed interventions was associated with the probability a smaller placebo effect size (β = −0.12; 95% CI, −0.23 to −0.01, P = .03). The Egger test result was not significant for small studies’ effects.
Conclusions and Relevance This analysis may provide a benchmark for past and future clinical RCTs that recruit patients with TRD standardizing an expected placebo effect size.
https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2784479
Key Points
Question What is the placebo effect magnitude in different treatment modalities used for management of patients with treatment-resistant depression?
Findings In this systematic review and meta-analysis of 3228 patients with treatment-resistant depression in 50 randomized clinical trials, the placebo effect size was large and consistent across treatment modalities. Response and remission rates associated with placebo effect were comparable across modalities.
Meaning The findings of this study suggest a placebo effect size benchmark may be used to interpret the findings of past and future clinical trials.
Results Fifty RCTs were included involving various types of placebo or sham interventions with a total of 3228 participants (mean [SD] age, 45.8 [6.0] years; 1769 [54.8%] female). The pooled placebo effect size for all modalities was large (g = 1.05; 95% CI, 0.91-1.1); the placebo effect size in RCTs of specific treatment modalities did not significantly differ. Similarly, response and remission rates associated with placebo were comparable across modalities. Heterogeneity was large. Three variables were associated with a larger placebo effect size: open-label prospective treatment before double-blind placebo randomization (β = 0.35; 95% CI, 0.11 to 0.59; P = .004), later year of publication (β = 0.03; 95% CI, 0.003 to 0.05; P = .03), and industry-sponsored trials (β = 0.34; 95% CI, 0.09 to 0.58; P = .007). The number of failed interventions was associated with the probability a smaller placebo effect size (β = −0.12; 95% CI, −0.23 to −0.01, P = .03). The Egger test result was not significant for small studies’ effects.
Conclusions and Relevance This analysis may provide a benchmark for past and future clinical RCTs that recruit patients with TRD standardizing an expected placebo effect size.
https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2784479