Table 3 Risk of bias assessment of the included studies according to the Newcastle-Ottawa Quality Assessment Scale
Study ID | Alharbi et al. 2020 [19] | Mentias et al. 2023 [18] | Oettinger et al. 2023 [31] | Rali et al. 2022 [32] | Stachon et al. 2020 [20] | Zhou et al. 2023 [21] |
|---|---|---|---|---|---|---|
Sample selection criteria (****) | **** | **** | **** | **** | **** | **** |
1) Representativeness of the exposed cohort (a) Truly representative (one star) (b) Somewhat representative (one star) (c) Selected group (d) No description of the derivation of the cohort | a | a | a | a | a | a |
2) Selection of the non-exposed cohort (a) Drawn from the same community as the exposed cohort (one star) (b) Drawn from a different source (c) No description of the derivation of the non-exposed cohort | a | a | a | a | a | a |
3) Ascertainment of exposure (a) Secure record (e.g., surgical record) (one star) (b) Structured interview (one star) (c) Written self-report (d) No description (e) Other | a | a | a | a | a | a |
4) Demonstration that outcome of interest was not present at the start of the study (a) Yes (one star) (b) No | a | a | a | a | a | a |
Comparability (**) | * | ** | Â | Â | Â | ** |
1) Comparability of cohorts on the basis of the design or analysis controlled for confounders (a) The study controls for age (one star) (b) Cohorts are not comparable on the basis of the design or analysis controlled for age (c) No available separate baseline data for the included population in the current meta-analysis | b | a | b | b | b | a |
(a)Study controls for other comorbidities$ (one star) (b) Cohorts are not comparable on the basis of the design or analysis controlled for comorbidities (c) No available separate baseline data for the included population in the current meta-analysis | a | a | b | b | b | a |
Exposure (***) | *** | *** | *** | *** | *** | *** |
1) Assessment of outcome (a) Independent blind assessment (one star) (b) Record linkage (one star) (c) Self-report (d) No description (e) Other | a | a | a | a | a | a |
2) Was follow-up long enough for outcomes to occur (a) Yes (one star) (b) No | a | a | a | a | a | a |
3) Adequacy of follow-up of cohorts (a) Complete follow up- all subjects accounted for (one star) (b) Subjects lost to follow-up unlikely to introduce bias- number lost less than or equal to 20% or description of those lost suggested no different from those followed. (one star) (c) Follow up rate less than 80% and no description of those lost (d) No statement | a | a | a | a | a | a |
Summary risk of bias score | Low | Low | Low | Low | Low | Low |