Since MetAnalysis and WEasyMA can only analyze data from two-by-two tables, the comparability assessments were limited to one data set [ 8].
For example, enhanced translation and verification methodologies are needed to ensure the comparability of assessment instruments across the range of languages and cultures participating in international surveys.
The methodological issues related to the accuracy and comparability of assessment based on attributable fraction include the following questions: Is the estimate of exposure used for assessing the effect valid?
The following items were assessed in each study: exposed cohort, ascertainment of exposure, outcome of interest, comparability of cohorts, assessment of outcome, and adequacy of follow-up.
In limited situations, where supported by a risk assessment, comparability protocols may be specified in filed documentation.
The scale evaluates selection of the cohort, exposure assessment, comparability of exposed and non-exposed cohorts, assessment of outcome, and adequacy of follow-up.
40 Using the Newcastle-Ottawa Scale, we will award each study a maximum of nine points for items related to selection, comparability and outcome assessment bias.
The NOS uses different tools for case-control and cohort studies and consists of 3 parameters of quality: selection, comparability, and exposure/outcome assessment.
The seven non-randomised controlled trials had a low to medium risk of bias for selection, and a low risk of bias for comparability and outcome assessment on the Newcastle Ottawa scale (table 2).
When methodological quality was assessed on the Newcastle-Ottawa Scale there was a medium risk of selection bias and a medium to high risk of bias in comparability and outcome assessment for most studies.
