Article type
Year
Abstract
Background: Despite an impressive increase of Chinese studies the interest in these studies is still relatively low in Western countries, and Chinese randomised controlled trials (RCTs) are rarely included in Western systematic reviews.
Objectives: We systematically reviewed blinded Chinese venlafaxine RCTs, based on a search in Chinese and western databases. This study aims at enhancing insight into the quality of Chinese RCTs and to investigate if venlafaxine is an effective treatment option in Chinese populations.
Methods: Chinese databases (CNKI/VIP) and western databases were searched for blinded randomized controlled trials. Trials comparing venlafaxine to other antidepressants or placebo were included if the patients had a diagnosis of depression according to CCMD, DSM or ICD. Effect sizes were calculated as Hedges' g for rating scale scores and Mantel-Haenszel risk ratios (MH RR) for response and remission data. Effect sizes were combined in a fixed-effects model.
Results: Twenty-five studies were included. Nine trials compared venlafaxine to SSRIs; placebo-controlled trials were lacking. Quality was at best modest. All trials were underpowered. There were more responders (MH RR, 1.08; 95% confidence interval [CI], 1.02-1.15) and remitters (MH RR, 1.12; 95% CI, 1.02-1.24) in venlafaxine groups compared with those in TCA groups. HAMD end point scores in the venlafaxine groups were lower (Hedges' g = 0.16; 95% CI, 0.04-0.27), and venlafaxine was better tolerated than tricyclic antidepressant (Hedges' g = 0.56; 95% CI, 0.37-0.74). There were no significant differences between venlafaxine and selective serotonin reuptake inhibitor on any of these parameters. Analyses of publication bias were inconclusive.
Conclusions: Chinese researchers have published a number of randomized controlled trials comparing venlafaxine to active comparators, but study quality was found to be low. To make optimal use of their research potential Chinese researchers will have to improve trial reporting and the peer-review process.
Objectives: We systematically reviewed blinded Chinese venlafaxine RCTs, based on a search in Chinese and western databases. This study aims at enhancing insight into the quality of Chinese RCTs and to investigate if venlafaxine is an effective treatment option in Chinese populations.
Methods: Chinese databases (CNKI/VIP) and western databases were searched for blinded randomized controlled trials. Trials comparing venlafaxine to other antidepressants or placebo were included if the patients had a diagnosis of depression according to CCMD, DSM or ICD. Effect sizes were calculated as Hedges' g for rating scale scores and Mantel-Haenszel risk ratios (MH RR) for response and remission data. Effect sizes were combined in a fixed-effects model.
Results: Twenty-five studies were included. Nine trials compared venlafaxine to SSRIs; placebo-controlled trials were lacking. Quality was at best modest. All trials were underpowered. There were more responders (MH RR, 1.08; 95% confidence interval [CI], 1.02-1.15) and remitters (MH RR, 1.12; 95% CI, 1.02-1.24) in venlafaxine groups compared with those in TCA groups. HAMD end point scores in the venlafaxine groups were lower (Hedges' g = 0.16; 95% CI, 0.04-0.27), and venlafaxine was better tolerated than tricyclic antidepressant (Hedges' g = 0.56; 95% CI, 0.37-0.74). There were no significant differences between venlafaxine and selective serotonin reuptake inhibitor on any of these parameters. Analyses of publication bias were inconclusive.
Conclusions: Chinese researchers have published a number of randomized controlled trials comparing venlafaxine to active comparators, but study quality was found to be low. To make optimal use of their research potential Chinese researchers will have to improve trial reporting and the peer-review process.