Table 2.
Risk of bias assessment according to the NOS and the AHRQ standards
| Study | Selection |
Comparability | Outcome |
Overall quality |
||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Representativeness of the exposed cohort a | Selection of the nonexposed cohort | Ascertainment of exposure | Demonstration that outcome of interest was not present at start of study | Comparability of cohorts on the basis of the design or analysis controlled for confounders b | Assessment of outcome | Follow-up long enough for outcomes c | Adequacy of follow-up of cohort | NOS | AHRQ | |
| De Giorgi et al, 2019 [25] | ★ | ★ | ★ | ★ | ★★ | ★ | ★ | ★ | 9 | Good quality |
| Labadie et al, 2020 [26] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 | Good quality | |
| Sanchez et al, 2020 [27] | ★ | ★ | ★ | ★★ | ★ | ★ | 7 | Good quality | ||
| Colomba et al, 2020 [28] | ★ | ★ | ★ | ★ | ★★ | ★ | ★ | 8 | Good quality | |
| Martini et al, 2020 [29] | ★ | ★ | ★ | ★★ | ★ | ★ | 7 | Good quality | ||
| Takemura et al, 2020 [30] | ★ | ★ | ★ | ★ | ★★ | ★ | ★ | 8 | Good quality | |
| Boi et al, 2020 [31] | ★ | ★ | ★ | ★ | ★★ | ★ | ★ | ★ | 9 | Good quality |
| Lalani et al, 2021 [32] | ★ | ★ | ★ | ★ | ★★ | ★ | ★ | 8 | Good quality | |
AHRQ = Agency for Healthcare Research and Quality; NOS = Newcastle-Ottawa Scale.
a
One NOS star was awarded for a multicentre cohort of patients.
b
Two NOS stars were awarded for multiple confounders, while one NOS star was awarded for a single confounder.
c
One NOS star was awarded for median follow-up of at least 12 mo.