Table 3.

Quality assessment of included studies—cross-sectional study

Author Year	1	2	3	4	5	6	7	8	9	10	11	Total points
De 2005 [28]	Y	N	Y	N	Y	N	Y	Y	N	Y	N	6
Kitsantas 2018 [30]	Y	N	Y	N	Y	N	N	Y	Y	Y	N	6
Ponsonby 1999 [31]	Y	Y	Y	N	Y	N	N	N	Y	Y	N	6
Kemp 2009 [29]	Y	N	Y	N	Y	Y	Y	Y	N	Y	N	7
Xu 1999 [36]	Y	N	Y	Y	Y	N	N	Y	N	Y	N	6
Strachan 1996 [27]	Y	N	Y	N	Y	N	Y	Y	N	Y	N	6

Y:Yes, N:No/Unclear; 1. Define the source of information (survey, record review); 2. List inclusion and exclusion criteria for exposed and unexposed subjects (cases and controls) or refer to previous publications; 3. Indicate time period used for identifying patients; 4. Indicate whether or not subjects were consecutive if not population-based; 5. Indicate if evaluators of subjective components of study were masked to other aspects of the status of the participants; 6. Describe any assessments undertaken for quality assurance purposes (eg, test/retest of primary outcome measurements; 7. Explain any patient exclusions from analysis; 8. Describe how confounding was assessed and/or controlled; 9. lf applicable, explain how missing data were handled in the analysis; 10. Summarize patient response rates and completeness of data collection; 11. Clarify what follow-up, if any, was expected and the percentage of patients for which incomplete data or follow-up was obtained