Table 2 New-castle Ottawa methodological quality of included non-randomized studies
Cohort Studies | Selection | Comparability | Outcome | Score | |||||
Representative-ness of exposed cohort | Selection of the non-exposed cohort | Ascertainment of exposure | Outcome of interest was not present at start of study | Comparability based on design or analysis | Assessment of outcome | Adequacy of follow up of cohorts | Loss to follow up < 20% | ||
Ding 2014 [14] | 1 | 1 | 1 | 0 | 2 | 0 | 1 | 1 | 7 |
Eckerdal 2019 [15] | 1 | 1 | 1 | 0 | 2 | 0 | 1 | 1 | 7 |
Gaillard 2014 [16] | 1 | 1 | 1 | 0 | 2 | 1 | 1 | 1 | 8 |
Nahirney 2017 [17] | 1 | 1 | 1 | 1 | 2 | 0 | 1 | 1 | 8 |
Orbach-Zinger 2018 [18] | 1 | 1 | 1 | 1 | 2 | 1 | 1 | 1 | 9 |
Riazanova 2018 [19] | 1 | 1 | 1 | 0 | 0 | 1 | 0 | 0 | 4 |
Tobin 2016 [21] | 1 | 1 | 1 | 0 | 0 | 0 | 1 | 0 | 4 |
Zhang 2018 [22] | 1 | 1 | 1 | 1 | 2 | 1 | 0 | 1 | 8 |
Case-Control Study | Selection | Comparability | Outcome | Score | |||||
Adequate definition of cases | Representativeness of cases | Selection of controls | Definition of controls | Comparability based on design or analysis | Ascertainment of exposure | Same method of ascertainment for cases and controls | Same response rate for both groups | ||
Suhitharan 2016 [20] | 1 | 1 | 1 | 1 | 2 | 1 | 1 | 1 | 9 |