Table 3 Quality assessment and risk of bias of the included non-randomized studies
Study | Coding manual for cohort studies | Newcastle–Ottawa Scale |
|---|---|---|
Turkyilmaz et al. [51] | Selection | |
(1) Representativeness of the exposed cohort | d | |
(2) Selection of the non-exposed cohort | a☆ | |
(3) Ascertainment of exposure | a☆ | |
(4) Demonstration that outcome of interest was not present at start of study | a☆ | |
Comparability | ||
(1) Comparability of cohorts on the basis of the design or analysis | a☆ | |
Outcome | ||
(1) Assessment of outcome | a☆ | |
(2) Was follow-up long enough for outcomes to occur | a☆ | |
(3) Adequacy of follow up of cohorts | a☆ | |
Total Scale | ☆☆☆☆☆☆☆ | |
De Smet et al. [50] | Selection | |
(1) Representativeness of the exposed cohort | d | |
(2) Selection of the non-exposed cohort | a☆ | |
(3) Ascertainment of exposure | a☆ | |
(4) Demonstration that outcome of interest was not present at start of study | a☆ | |
Comparability | ||
(1) Comparability of cohorts on the basis of the design or analysis | a☆ | |
Outcome | ||
(1) Assessment of outcome | a☆ | |
(2) Was follow-up long enough for outcomes to occur | a☆ | |
(3) Adequacy of follow up of cohorts | b☆ | |
Total Scale | ☆☆☆☆☆☆☆ | |