Table 2.

NOS evaluation criteria for queue study.

Column	Entry#	Evaluation Criterion
Study population selection	How representative is the exposure group (1 point)	① It truly represents the characteristics of the exposure group in the population*; ② To some extent, it represents the characteristics of the exposure group in the population*; ③ Select a certain group of people, such as medical students; ④ Source of exposure group is not described
	Selection method of the non-exposure group (1 point)	① From the same population*; ② From different populations; ③ The source of the non-exposure group is not described
	Determination method of exposure factors (1 point)	① Fixed file records*; ② Structured interview*; ③ Reports written by the research subjects themselves; ④ Not described
	Determine the outcome indicators that do not need to be observed at the beginning of the study (1 point)	① Yes*; ② No
Comparability between groups	Consider the comparability of exposed group and non-exposed group when involving and statistical analysis (2 points)	① The study controlled the most important confounding factor*; ② The study controlled for any other confounding factors*
Result measurement	Whether the evaluation of research results is sufficient (1 point)	① Blind independent evaluation*; ② Archives*; ③ Self-reporting; ④ Not described
	Whether the follow-up time is enough after the occurrence of results (1 point)	① Yes (specify appropriate follow-up time before evaluation)*; ② No
	Whether the follow-up of exposure group and non-exposure group is sufficient (1 point)	① Follow up was complete*; ② A small number of subjects lost interviews without bias*; ③ Loss of follow-up but not described; ④ Follow-up is not described

^#score entry.

^*score points.