Table 2.
Risk of bias among matched cohort studies
| Study | Risk of biasa | ||||||
|---|---|---|---|---|---|---|---|
| Due to Confounding | In Selection | In measurement classification of interventions | Due to deviations from intended interventions | Due to missing data | In measurement of outcomes | In selection of the reported results | |
| Gårdlund [23]/1993 | Low | Low | Low | Low | Low | Low | Low |
| Stegmayr [52]/1995 | Moderate | Moderate | Low | Low | Low | Low | Low |
| Stegmayr [53]/1996 | Low | Low | Low | Low | Low | Low | Low |
| Hjorth [54]/2000 | Low | Low | Low | Low | Low | Low | Low |
| Schmidt [55]/2000 | Serious | Moderate | Low | Low | Low | Low | Low |
| Ataman [56]/2002 | Serious | Serious | Moderate | Low | Low | Low | Low |
| Stegmayr [57]/2003 | Moderate | Low | Low | Low | Low | Low | Low |
| Hadem [32]/2014 | Low | Low | Low | Low | Low | Low | Low |
| Knaup [58]/2018 | Low | Low | Low | Low | Low | Low | Low |
| Keith [59]/2020 | Low | Low | Low | Low | Low | Low | Low |
| Ahmed [60]/2020 | Low | Low | Low | Low | Low | Low | Low |
| Gucyetmez [61]/2020 | Moderate | Low | Low | Low | Low | Low | Low |
| Khamis [62]/2020 | Low | Low | Low | Low | Low | Low | Low |
| Kamran [63]/2021 | Low | Low | Low | Low | Low | Low | Low |
| Jaiswal [64]/2021 | Low | Low | Low | Low | Low | Low | Low |
aRisk of bias was assessed using the Risk of Bias in Non-Randomized Studies of interventions (ROBINS-I) for interventional studies. “Low risk,” “Moderate risk,” “Serious risk,” “Critical risk,” and “No information”