Article type
Year
Abstract
Background: There is broad consensus that there is a gap between the 'efficacy' of a drug proven in randomized controlled trials (RCTs) and the 'effectiveness' of that drug in everyday clinical practice. This consensus is mainly based on anecdotal evidence.
Objectives: This study systematically reviewed and compared evidence from RCTs and nonrandomized and uncontrolled trials examining the effectiveness of venlafaxine and duloxetine in the treatment of depression.
Methods: The systematic review used pre-post effect sizes to compare treatment effects from RCTs and non-RCTs examining the effects of duloxetine, venlafaxine and placebo in the treatment of depression. Data were aggregated in random-effects models. Meta-regressions were used to explore factors influencing the effect sizes.
Results: One-hundred and ninety relevant studies were identified, and effect sizes for 114 acute-phase studies could be calculated. All interventions, including placebo, showed a statistically significant pre-post effect of more than two standard deviations. Between-study heterogeneity was high. However, there were no significant differences of effect sizes from RCTs and non-RCTs, and metaregressions did not show a significant influence of external validity measured by the Downs and Black scale.
Conclusions: The analyses could not confirm the presence of an efficacy-effectiveness gap.It is possible that the impression of such a gap existing is a consequence of publication bias rather than being due to RCT-practice differences.
Objectives: This study systematically reviewed and compared evidence from RCTs and nonrandomized and uncontrolled trials examining the effectiveness of venlafaxine and duloxetine in the treatment of depression.
Methods: The systematic review used pre-post effect sizes to compare treatment effects from RCTs and non-RCTs examining the effects of duloxetine, venlafaxine and placebo in the treatment of depression. Data were aggregated in random-effects models. Meta-regressions were used to explore factors influencing the effect sizes.
Results: One-hundred and ninety relevant studies were identified, and effect sizes for 114 acute-phase studies could be calculated. All interventions, including placebo, showed a statistically significant pre-post effect of more than two standard deviations. Between-study heterogeneity was high. However, there were no significant differences of effect sizes from RCTs and non-RCTs, and metaregressions did not show a significant influence of external validity measured by the Downs and Black scale.
Conclusions: The analyses could not confirm the presence of an efficacy-effectiveness gap.It is possible that the impression of such a gap existing is a consequence of publication bias rather than being due to RCT-practice differences.