Table 2: Quality assessment scheme using Newcastle-Ottawa Scale for cohort studies.
|
Selection |
Comparability |
Outcome |
||||||||
|
Study |
Representativeness of exposed cohort |
Selection of non- exposed cohort |
Ascertainment of exposure |
Demonstration that outcome of interest was not present at the start of the study |
Study controls for age/sex |
Study controls for additional factors |
Assessment of outcome |
Follow-up was long enough |
Adequacy of follow-up of cohorts |
Rating |
|
Maxwell, et al. [21] |
★ |
★ |
★ |
★ |
★ |
★ |
★ |
★ |
Good |
|
|
Bronco, et al. [25] |
★ |
★ |
★ |
★ |
★ |
★ |
★ |
★ |
★ |
Good |
|
Teo, et al. [26] |
★ |
★ |
★ |
★ |
★ |
★ |
★ |
Good |
||
|
Lim, et al. [27] |
★ |
★ |
★ |
★ |
★ |
★ |
★ |
Good |
||
|
Warren, et al. [28] |
|
★ |
★ |
★ |
★ |
★ |
★ |
★ |
★ |
Good |
|
Smyth, et al. [31] |
|
★ |
★ |
★ |
★ |
★ |
★ |
★ |
Good |
|
Good quality = 3-4 stars (★) in selection AND 1-2 stars in comparability AND 2-3 stars in outcome;
Fair quality = 2 stars in selection AND 1-2 stars in comparability AND 2-3 stars in outcome;
Poor quality = 0-1 star in selection OR 0 star in comparability OR 0-1 star in outcome.