Table 5 Summary of precision and risk of bias (ROB) assessment for the hepatitis C virus (HCV) incidence and prevalence measures extracted from eligible reports.

From: The epidemiology of hepatitis C virus in Iran: Systematic review and meta-analyses

Quality assessment HCV incidence HCV prevalence
n % n %
Precision of estimates
High precision 3 60.0 312 77.4
Low precision 2 40.0 79 19.6
Uncleara    12 3.0
Risk of bias quality domains
 HCV ascertainment
Low risk of bias 5 100 402 100
High risk of bias 0 0 0 0
Sampling methodology
Low risk of bias 0 0 48 11.9
High risk of bias 5 100 350 87.1
Unclear 0 0 4 1.0
Response rate
Low risk of bias 3 60.0 370 92.0
High risk of bias 2 40.0 10 2.5
Uncleara 0 0 22 5.5
Total studies where risk of bias assessment was possible 5 100 402 99.8
Unknown b 0 0   0.2
Total studies 5 100 403 100
Summary of risk of bias assessment for HCV prevalence measures n %   
Low risk of bias
In at least one quality domain 402 100   
In at least two quality domains 371 92.3   
In all three quality domains 47 11.7   
High risk of bias
In at least one quality domain 350 87.1   
In at least two quality domains 10 2.5   
In all three quality domains 0 0   
Total studies where risk of bias assessment was possible 402 99.8   
Total studies 403 100   
  1. aStudies with missing information for any of the domains were classified as having unclear risk of bias for that specific domain.
  2. bStudies extracted through country-level routine reporting with limited description of the sample (not permitting the conduct of risk of bias assessment) were classified as being of unknown quality.