Table 2 Quality assessment of included studies

Define source of information (survey or review)

List inclusion and exclusion criteria for exposed and unexposed subjects (cases and controls) or refer to previous publications

Indicate

time period used to identify patients

Indicate whether subjects were consecutive if not population-

based

Indicate if evaluators of subjective components of study were masked to, Other aspects of the status of the participants

Describe any assessments undertaken for quality assurance purposes

Explain any patient exclusions from analysis

Describe how confounding variables were assessed or controlled for

If applicable, explain how missing data were handled in the analysis

Summarise patient response rate and completeness of data collection

Clarify what follow-up, if any, was expected and the percentage of patients for whom incomplete data or follow-up was obtained

Yi-Liang (2015) [20]

Y

Y

Y

U

U

Y

N

Y

N

Y

N

6

Ito (2018) [21]

Y

Y

Y

U

N

Y

N

N

U

Y

N

5

Brumagne (2004) [22]

Y

N

N

N

U

Y

N

Y

U

Y

N

4

Ito (2017) [23]

Y

Y

Y

U

N

Y

N

Y

U

Y

N

6

Lee (2016) [24]

Y

Y

Y

U

N

Y

N

Y

N

Y

N

6

Iversen (2009) [25]

Y

Y

Y

U

U

Y

N

Y

N

Y

N

6

Kendall (2018) [26]

Y

Y

Y

U

N

Y

N

Y

N

Y

N

6

Sung (2017) [27]

Y

Y

Y

Y

N

Y

N

Y

N

Y

N

7

Lihavainen

(2010) [28]

Y

Y

N

Y

N

N

Y

N

Y

Y

N

6

Champagne

(2012) [29]

Y

Y

N

Y

N

Y

N

N

Y

Y

N

6

Hicks (2018) [30]

Y

Y

Y

U

N

Y

N

N

N

Y

N

5

Silva (2016) [31]

Y

Y

Y

Y

N

Y

N

N

N

Y

N

6

Kato (2019) [32]

Y

Y

N

Y

N

Y

N

U

N

Y

N

5