Table 3.
Individual risk of bias assessment for cohort studies: review authors’ judgements about each risk of bias factor among the selected studies.
| Quality analysis of cohort studies | Danza 2009 | Behneke 2012 | Arisan 2013 | Choi 2017 | Ravida 2018 |
|---|---|---|---|---|---|
| Were the two groups similar and recruited from the same population? | u | y | y | u | y |
| Were the exposures measured similarly to assign people to both exposed and unexposed groups? | y | y | y | u | y |
| Was the exposure measured in a valid and reliable way? | y | y | y | y | y |
| Were confounding factors identified? | n | n | n | y | y |
| Were strategies to deal with confounding factors stated? | y | n | n | n | y |
| Were the groups/participants free of the outcome at the start of the study (or at the moment of exposure)? | y | u | y | y | y |
| Were the outcomes measured in a valid and reliable way? | y | n | y | n | y |
| Was the follow up time reported and sufficient to be long enough for outcomes to occur? | y | n | n | n | y |
| Was the follow up complete, and if not, were the reasons to loss to follow up described and explored? | u | n | n | n | y |
| Were strategies to address incomplete follow up utilized? | u | n | n | n | n |
| Was appropriate statistical analysis used? | y | y | y | y | y |
| Total % | 63% | 36% | 54% | 36% | 90% |
Seven domains were analyzed for each record, and final judgments were made by discussion between authors.
y yes, n no, u unclear.