Table 1 Quality assessment according to the New Ottowa Scale (NOS)
First author (year) | Selection | Comparability | Outcome | Total | ||||
|---|---|---|---|---|---|---|---|---|
Representativeness of the samples | Sample size calculation | Non-respondents | Ascertainment of the exposure (risk factor) | Adjustment for confounders | Assessment of the outcome | Statistical test | ||
Widener (2018)a | 0 | 1 | 0 | 1 | 1 | 1 | 1 | 5 |
Wray (2021)b | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 4 |
Sadler (2016)c | 0 | 1 | 0 | 1 | 2 | 1 | 1 | 6 |
Shearer (2015)d | 0 | 1 | 0 | 1 | 2 | 1 | 0 | 5 |
Zenke | 1 | 0 | 0 | 1 | 1 | 1 | 0 | 4 |
Ellistion (2020)f | 1 | 1 | 0 | 1 | 0 | 1 | 0 | 4 |
Gustafson (2013)g | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 5 |
Ghosh Roy (2019)h | 0 | 1 | 0 | 1 | 1 | 1 | 1 | 5 |
Seto (2016)i | 1 | 1 | 0 | 1 | 2 | 1 | 1 | 7 |
Liu (2020)j | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 5 |
Christian (2012)k | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 6 |
Burgoine (2015)l | 0 | 0 | 0 | 1 | 1 | 2 | 1 | 5 |
Tamura (2018)m | 0 | 1 | 1 | 1 | 1 | 2 | 1 | 7 |
Wang (2018)n | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 5 |