Table 4.

Quality evaluation of cross-sectional study.

Author	1	2	3	4	5	6	7	8	9	Total score
Villarreal 2003[14]	√	√	√	√	√	√	?	√	√	89%
Obihara 2005[24]	√	√	√	√	√	√	?	√	√	89%
Horak 2007[20]	√	√	√	√	√	√	?	√	×	78%
Hugg 2007[31]	?	?	?	√	√	√	?	√	×	44%
Lee 2012[16]	√	√	√	√	?	√	?	√	√	78%
Chen 2012[15]	√	√	√	√	√	×	√	√	×	78%
Azalim 2014[25]	√	√	√	√	√	√	?	√	×	78%
Li 2019[26]	√	√	√	√	?	×	√	√	?	67%
Huang 2019[11]	√	√	√	√	?	×	?	√	×	56%

√: yes; ×: no; ?:unclear; ^∗: not applicable.

1 Was the sample frame appropriate to address the target population?

2 Were study participants sampled in an appropriate way?

3 Was the sample size adequate?

4 Were the study subjects and the setting described in detail?

5 Was the data analysis conducted with sufficient coverage of the identified sample?

6 Were valid methods used for the identification of the condition?

7 Was the condition measured in a standard, reliable way for all participants?

8 Was there appropriate statistical analysis?

9 Was the response rate adequate, and if not, was the low response rate managed appropriately?