Study (year) | Conflict of Interests | Ethical Approval | Downs and Black checklist | GRADE |
|---|
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Total | Score# |
|---|
Chen at al. 2020 | No | Yes | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 14 | 80% | 
|
He at al. 2016 | No | Yes | 1 | 1 | 1 | 0 | 1 | 1 | _ | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | _ | 12 | 80% | 
|
Li at al. 2019 | No | Yes | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 14 | 80% | 
|
Luo at al. 2018 | No | * | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 13 | 76% | 
|
Hevia at al. 2014 | * | Yes | 1 | 1 | 1 | 0 | 1 | 1 | _ | 1 | 1 | 1 | _ | 1 | 1 | _ | 0 | _ | 10 | 76% | 
|
- Downs and Black checklist: A) objective clearly stated; B) main outcomes clearly described; C) sample characteristics clearly defined; D) distribution of principal confounders clearly described; E) main findings clearly defined; F) random variability in estimates provided; G) lost to follow-up described; H) probability values reported; I) sample target representative of population; J) sample recruitment representative of population; K) analyses adjusted for different follow-up duration; L) statistical tests appropriately used; M) primary outcomes valid/reliable; N) sample recruited from the same population; O) adequate adjustment for confounding; and P) losses of sample to follow-up taken into account (corresponding to questions 1–3, 5–7, 9–12, 17,18, 20, 21, 25,26). Questions G and P were applied only for longitudinal studies. Questions K and N were applied only for case-control and longitudinal studies
- # Score reaches 100% with 13, 15, and 17 points for cross-sectional, case-control, and longitudinal studies, respectively
- *, not reported, −, not applied
- GRADE, Grading of Recommendations, Assessment, Development and Evaluations; one filled circle, very low quality; two filled circles, low quality; three filled circles, moderate quality; four filled circles, high quality
