Table 2. Methodological quality of included studies.

Study	11-item check list recommended by AHRQ checklist
	i	ii	iii	iv	v	vi	vii	viii	ix	x	xi	Score	Quality
Shin 2021[17]	★	★	★			★	★	★				6	M
Hondur 2021[18]		★			★	★		★				4	M
Fard 2020[19]	★	★	★			★	★	★		★		7	M
Robolleda 2019[20]	★	★				★	★	★				5	M
Resch 2018[22]	★	★				★	★	★				5	M
Fard 2018[24]	★	★	★				★	★		★		6	M
Liu 2017[25]	★	★	★				★					4	M
Lee 2017[26]	★	★	★					★		★		5	M
Fard 2016[29]	★	★	★	★		★	★	★				7	M
Fard 2016[28]	★	★	★				★	★		★		6	M

AHRQ: Agency for Healthcare Research and Quality; H: High quality; M: Moderate quality; L: Low quality; high quality (score: 8-11); moderate quality (score: 4-7); low quality (score: 0-3). i: Define the source of information; ii: List inclusion and exclusion criteria for exposed and unexposed subjects (cases and controls) or refer to previous publications; iii: Indicate time period used for identifying patients; iv: Indicate whether or not subjects were consecutive if not population-based; v: Indicate if evaluators of subjective components of study were masked to other aspects of the status of the participants; vi: Describe any assessments undertaken for quality assurance purposes; vii: Explain any patient exclusions from analysis; viii: Describe how confounding was assessed and/or controlled; ix: If applicable, explain how missing data were handled in the analysis; x: Summarize patient response rates and completeness of data collection; xi: Clarify what follow-up, if any, was expected and the percentage of patients for which incomplete data or follow-up was obtained.