Table 2.

Quality assessment.

	Yes	No
Describe all statistical methods, including those used to control for confounding	11 (52.38%)	10 (47.62%)
Describe any methods used to examine subgroups and interactions	20 (95.24%)	1 (4.76%)
Explain how missing data were addressed	11 (52.38%)	10 (47.62%)
Consider use of a flow diagram (for missing variables)	14 (66.67%)	7 (33.33%)
Indicate number of participants with missing data for each variable of interest	4 (19.05%)	17 (80.95%)
Give unadjusted estimates and, if applicable, confounder-adjusted estimates and their precision (e.g., 95% confidence interval). Make clear which confounders were adjusted for and why they were included	7 (33.33%)	14 (66.67%)
Discuss limitations of the study, taking into account sources of potential bias or imprecision. Discuss both direction and magnitude of any potential bias	19 (95.24%)	2 (9.52%)
Give the source of funding and the role of the funders for the present study and, if applicable, for the original study on which the present article is based	20 (95.24%)	1 (4.76%)