Article type
Abstract
"Background: The impact of blinding and different types of blinding on treatment effects in acupuncture RCTs, which mainly focus on subjective outcomes like pain, is still uncertain due to potential bias in implementation and measurement.
Objectives: To evaluate the sole impact of blinding patients and outcome assessors in acupuncture randomized controlled trials (RCTs) on treatment effects while considering the type of outcome measures..
Methods: We searched the PubMed and Embase databases for the meta-analyses on acupuncture with both blinded and non-blinded RCTs. Blinding status was retrieved from trial publications. Mixed-effects meta-regression models estimated the average ratio of odds ratios (ROR) and differences in standardized mean differences (dSMD) for non-blinded RCTs versus blinded mixed-effects meta-regression model. An ROR greater than 1 or a negative dSMD indicates an overestimation of the treatment effect in non-blinded trials. Subgroup analyses were conducted according to the type of acupuncture, language of publication, and type of control.
Results: The study included 33 meta-analyses. The average ROR for lack of patient blinding was 0.73 (95% confidence intervals 0.37 to 1.46) in meta-analyses with binary patient reported outcomes. The average ROR for lack of outcome assessor blinding was 0.50 (0.17 to 1.46) in meta-analyses with binary subjective outcomes. The average dSMD was -0.57 (-1.19 to 0.05) in meta-analyses with continuous patient-reported outcomes. The average dSMD was -0.20 (-0.88 to 0.48) in meta-analyses with continuous subjective outcomes. The results of the subgroup analysis were consistent with the primary analysis findings.
Conclusions: While our study found no significant effect of blinding on acupuncture RCT results, whether blinding patients or outcome assessors, caution should be exercised when interpreting this result due to limitations in the design or conduct of the included trials or potential confounding factors in our meta-epidemiological study. Future research should aim to investigate the impact of blinding on acupuncture RCT outcomes by comparing open-label studies with successful blinding.
"
Objectives: To evaluate the sole impact of blinding patients and outcome assessors in acupuncture randomized controlled trials (RCTs) on treatment effects while considering the type of outcome measures..
Methods: We searched the PubMed and Embase databases for the meta-analyses on acupuncture with both blinded and non-blinded RCTs. Blinding status was retrieved from trial publications. Mixed-effects meta-regression models estimated the average ratio of odds ratios (ROR) and differences in standardized mean differences (dSMD) for non-blinded RCTs versus blinded mixed-effects meta-regression model. An ROR greater than 1 or a negative dSMD indicates an overestimation of the treatment effect in non-blinded trials. Subgroup analyses were conducted according to the type of acupuncture, language of publication, and type of control.
Results: The study included 33 meta-analyses. The average ROR for lack of patient blinding was 0.73 (95% confidence intervals 0.37 to 1.46) in meta-analyses with binary patient reported outcomes. The average ROR for lack of outcome assessor blinding was 0.50 (0.17 to 1.46) in meta-analyses with binary subjective outcomes. The average dSMD was -0.57 (-1.19 to 0.05) in meta-analyses with continuous patient-reported outcomes. The average dSMD was -0.20 (-0.88 to 0.48) in meta-analyses with continuous subjective outcomes. The results of the subgroup analysis were consistent with the primary analysis findings.
Conclusions: While our study found no significant effect of blinding on acupuncture RCT results, whether blinding patients or outcome assessors, caution should be exercised when interpreting this result due to limitations in the design or conduct of the included trials or potential confounding factors in our meta-epidemiological study. Future research should aim to investigate the impact of blinding on acupuncture RCT outcomes by comparing open-label studies with successful blinding.
"