Table 2.
Risk of bias assessment.
| First author/year | Study design | Bias due to confounding | Bias in selection of participants | Bias in classification of interventions | Bias due to deviations from intended interventions | Bias due to missing data | Bias in measurement of outcomes | Bias in selection of reported results | Overall risk of bias |
|---|---|---|---|---|---|---|---|---|---|
| Mayet 2011 | Cross-sectional | Moderate | Low | Low | Low | Low | Moderate | Low | Moderate |
| Chang 2012 | Cross-sectional | Moderate | Low | Low | Low | Low | Moderate | Low | Moderate |
| Cruciani 2005 | Cross-sectional | Serious (confounding, small n) | Low | Low | Low | Low | Moderate | Low | Serious |
| Demarie 2011 | Cross-sectional | Moderate | Low | Low | Low | Low | Moderate | Low | Moderate |
| Krantz 2008 | Retrospective cohort | Serious | Low | Low | Low | Moderate | Moderate | Low | Serious |
| Esfahani 2012 | Retrospective cohort | Moderate | Low | Low | Low | Moderate | Moderate | Low | Moderate |
| Fanoe 2007 | Cross-sectional | Moderate | Low | Low | Low | Low | Moderate | Low | Moderate |
| Anchersen 2009 | Cross-sectional | Moderate | Low | Low | Low | Low | Moderate | Low | Moderate |
| Katz 2015 | Cross-sectional | Moderate | Low | Low | Low | Low | Low | Low | Moderate |
| Hassamal 2015 | Retrospective cohort | Serious (veterans only) | Moderate | Low | Low | Low | Moderate | Low | Serious |
| Maremmani 2005 | Retrospective cohort | Serious (heterogeneous doses) | Low | Low | Low | Low | Moderate | Low | Serious |
| Fareed 2013 | Retrospective cohort | Serious (long-term follow-up) | Low | Low | Low | Moderate | Moderate | Low | Serious |
| Peles 2007 | Cross-sectional | Moderate | Low | Low | Low | Low | Low | Low | Moderate |
| Pearson 2005 | Retrospective cohort | Serious (FDA reports) | High (selected cases) | Low | Low | Low | Serious | Low | Serious |
| Perrin-Terrin 2011 | Cross-sectional | Moderate | Low | Low | Low | Low | Moderate | Low | Moderate |
| Soroosh 2019 | Cross-sectional | Moderate | Low | Low | Low | Low | Moderate | Low | Moderate |
| Zerdazi 2019 | Retrospective cohort | Serious (gene-dose interaction, limited generalizability) | Low | Low | Low | Low | Moderate | Low | Serious |
| Farsi 2014 | Cross-sectional | Moderate | Low | Low | Low | Low | Moderate | Low | Moderate |
| Stallvik 2013 | Cross-sectional | Moderate | Low | Low | Low | Low | Moderate | Low | Moderate |
| Ehret 2006 | Retrospective cohort | Serious | Low | Low | Low | Low | Moderate | Low | Serious |
| Santin 2023 | Retrospective cohort | Serious | Low | Low | Low | Low | Moderate | Low | Serious |
| Titus-Lay 2021 | Prospective | Low | Low | Low | Low | Low | Low | Low | Low |
| Chang 2022 | Retrospective cohort | Moderate | Low | Low | Low | Low | Moderate | Low | Moderate |
| Gheshlaghi 2013 | Comparative observational | Moderate | Low | Low | Low | Low | Moderate | Low | Moderate |
| Deuss 2024 | Retrospective cohort | Serious (real-world, EHR-based) | Low | Low | Low | Low | Moderate | Low | Serious |
EHR = electronic health record, FDA = Food and Drug Administration.