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Research article
The Risk of Bias in Iranian Randomized Controlled Trials Included in Cochrane Reviews
Bita Mesgarpour
Cochrane Iran
Corresponding Author
ORCiD: https://orcid.org/0000-0002-4004-8493
License:
This work is licensed under a CC BY 4.0 License. Read Full License
Background: Among interventional studies, randomized controlled trials (RCTs) provide the most conclusive evidence. However, RCTs can be susceptible to the risk of bias (RoB). Systematic reviews can be performed to appraise the RoB in the included articles using evaluative tools. This study aimed to describe the main characteristics and focus on the ROB of RCTs conducted in Iran and included in Cochrane Reviews (CRs).
Methods: We searched "Iran" by selecting the "Search All Text" and "Review" fields in the Cochrane Database of Systematic Reviews within Ovid. CRs that included the RCTs conducted in Iran were retrieved. A trial was selected only if it was included in CRs, described as a controlled clinical trial, involved human subjects and its RoB was assessed by CR authors. The trials were characterized by investigating the relevant articles and the table "Characteristics of included studies" in each CR. The RoB was investigated by collecting the judgments of the review authors made based on tables of RoB assessment in the CRs.
Results: Out of 1166 Iranian RCTs included by 571 CRs, a low RoB was found in 44.9% for random sequence generation, 20.8% for allocation concealment, 32.3% for blinding of participants/personnel, 36.5% for blinding of outcome assessors, 56.3% for incomplete outcome data, 41.3% for selective outcome reporting and 53.8% for other sources of bias.
Conclusion: The RoB in Iranian RCTs was found to be mostly high or unclear. It is therefore recommended that the methodological quality of RCTs be seriously addressed in Iran.
Keywords
Systematic review, evidence-based medicine, randomized controlled trial, Iran, Cochrane
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This is a preprint. It has not completed peer review.
Research article
The Risk of Bias in Iranian Randomized Controlled Trials Included in Cochrane Reviews
Bita Mesgarpour
Cochrane Iran
Corresponding Author
ORCiD: https://orcid.org/0000-0002-4004-8493
Badges
Prescreen
This manuscript passed our Prescreen assessment
Complete author information
Appropriate declaration statements
Potential risks to human health
Prescreen
History
CURRENT STATUS: Posted
Version 1
Posted 22 Sep, 2020
No community comments so far
Metrics
Comments: 0
PDF Downloads: ...
HTML Views: ...
Subject Areas
Health Economics & Outcomes Research
License:
This work is licensed under a CC BY 4.0 License. Read Full License
Background: Among interventional studies, randomized controlled trials (RCTs) provide the most conclusive evidence. However, RCTs can be susceptible to the risk of bias (RoB). Systematic reviews can be performed to appraise the RoB in the included articles using evaluative tools. This study aimed to describe the main characteristics and focus on the ROB of RCTs conducted in Iran and included in Cochrane Reviews (CRs).
Methods: We searched "Iran" by selecting the "Search All Text" and "Review" fields in the Cochrane Database of Systematic Reviews within Ovid. CRs that included the RCTs conducted in Iran were retrieved. A trial was selected only if it was included in CRs, described as a controlled clinical trial, involved human subjects and its RoB was assessed by CR authors. The trials were characterized by investigating the relevant articles and the table "Characteristics of included studies" in each CR. The RoB was investigated by collecting the judgments of the review authors made based on tables of RoB assessment in the CRs.
Results: Out of 1166 Iranian RCTs included by 571 CRs, a low RoB was found in 44.9% for random sequence generation, 20.8% for allocation concealment, 32.3% for blinding of participants/personnel, 36.5% for blinding of outcome assessors, 56.3% for incomplete outcome data, 41.3% for selective outcome reporting and 53.8% for other sources of bias.
Conclusion: The RoB in Iranian RCTs was found to be mostly high or unclear. It is therefore recommended that the methodological quality of RCTs be seriously addressed in Iran.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5