Table 1.
Study quality assessment.
| Reference | Q1a | Q2b | Q3c | Q4d | Q5e | Q6f | Q7g | Q8h | Q9i | Q10j | Q11k | Q12l | Q13m | Q14n | Total Score | Rank |
| Wang et al [21], 2013 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 12 | high |
| Burdisso et al [14], 2019 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 12 | high |
| Nguyen et al [22], 2014 | 1 | 0 | 0 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 10 | medium |
| Fatima et al [23], 2018 | 1 | 0 | 0 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 10 | medium |
| Tung & Lu [15], 2016 | 0 | 0 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 9 | medium |
| Husseini Orabi et al [24], 2018 | 1 | 0 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 10 | medium |
| Islam et al [19], 2018 | 1 | 1 | 0 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 11 | high |
| Shen et al [6], 2017 | 0 | 1 | 0 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 9 | medium |
| De Choudhury, Gamon [25], et al, 2013 | 0 | 0 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 10 | medium |
| Mariñelarena-dondena et al [26], 2017 | 0 | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 10 | medium |
| Tsugawa et al [27], 2015 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 13 | high |
| Chen et al [28], 2018 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 6 | low |
| De Choudhury, Counts [29], et al, 2013 | 0 | 0 | 0 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 9 | medium |
| Dinkel et al [30], 2019 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 6 | low |
| Sadeque et al [7], 2017 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 12 | high |
| Shatte et al [31], 2020 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 0 | 1 | 1 | 12 | high |
| Li et al [32], 2020 | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 0 | 1 | 1 | 1 | 0 | 1 | 0 | 10 | medium |
aQ1: Was the research question or objective in this paper clearly stated?
bQ2: Was the study population clearly specified and defined?
cQ3: Was the participation rate of eligible persons at least 50%?
dQ4: Were all the subjects selected or recruited from the same or similar populations? Were inclusion and exclusion criteria for being in the study prespecified and applied uniformly to all participants?
eQ5: Was a sample size justification, power description, or variance and effect estimates provided?
fQ6: Were the exposure(s) of interest measured before the outcome(s) were measured?
gQ7: Was the timeframe sufficient so that one could reasonably expect to see an association between exposure and outcome if it existed?
hQ8: For exposures that can vary in amount or level, did the study examine different levels of the exposure in relation to the outcome?
iQ9: Were the exposure measures clearly defined, valid, reliable, and implemented consistently across all study participants?
jQ10: Were the exposure(s) assessed more than once over time?
kQ11: Were the outcome measures clearly defined, valid, reliable, and implemented consistently across all study participants?
lQ12: Were the outcome assessors blinded to the exposure status of participants?
mQ13: Was loss to follow-up after baseline 20% or less?
nQ14: Were key potential confounding variables measured and their impact on the relationship between exposure(s) and outcome(s) statistically adjusted for?