Newcastle-Ottawa scale | P.M Cawthon 2017 [17] | S.Gariballa 2013 [16] | L.Bianch 2016 [14] | T.Henwood 2017 [18] | M.Yang 2017 [15] | |
---|---|---|---|---|---|---|
Selection(4) | Representativeness of the exposed cohort | 1 | 1 | 1 | 0 | 1 |
 | Selection of the non-exposed cohort | 1 | 1 | 1 | 1 | 1 |
 | Ascertainment of exposure | 1 | 1 | 1 | 1 | 1 |
 | Demonstration that outcome of interest was not present at start of study | 1 | 1 | 1 | 1 | 1 |
Comparability(2) | Comparability of cohorts on the basis of the design or analysis | 1 | 0 | 0 | 1 | 2 |
Outcome(3) | Assessment of outcome | 1 | 1 | 1 | 1 | 1 |
 | Was follow-up long enough for outcome to occur | 1 | 0 | 1 | 0 | 0 |
 | Adequacy of follow up of cohorts | 1 | 1 | 1 | 1 | 1 |
Quality(9) | Total | 8 | 6 | 7 | 6 | 8 |