Table 2.

Summary of quality assessment for included studies using the Newcastle-Ottawa Scale for cohort studies, evaluating selection, comparability, and outcome domains

Newcastle Ottawa Quality Assessment Scale
Study name			Selection				Comparability		Outcome
			1	2	3	4	5	6	7	8	9
Hu et al. [20] (2009)			*	*	*	*	*	-	*	*	*
Werther et al. [21] (2011)			*	*	*	*	*	-	*	*	-
Capua et al. [22] (2012)			*	*	*	*	*	-	*	*	*
Bertelsen et al. [23] (2012)			*	*	*	*	*	*	*	*	*
Bertelsen et al. [24] (2014)			*	*	*	*	*	*	*	*	*
Shih et al. [25] (2015)			*	*	*	*	*	*	*	*	*
Hsieh et al. [26] (2016)			*	*	*	*	*	-	*	*	*
Rim et al. [27] (2016)			*	*	*	*	*	*	*	*	*
Chen et al. [28] (2017)			*	*	*	*	*	*	*	*	*
Umeya et al. [29] (2021)			*	*	*	*	*	-	*	*	*
Wai et al. [30] (2023)			*	-	*	*	*	-	*	*	*
Wai et al. [31] (2024)			*	*	*	*	*	*	*	*	*
Newcastle-Ottawa Quality Assessment Scale
Selection:	1	Representation of the intervention cohort
	2	Selection of the non-intervention cohort
	3	Has the correct intervention been utilized?
	4	Outcome of Interest present at the start of study?
Comparability:	5	Are the cohorts comparable based on the design or analysis: age, sex, and injury severity?
	6	Are the cohorts comparable based on the design or analysis? Additional factors
Outcome:	7	Was the outcome assessed?
	8	Was the follow-up long enough for measured outcomes to occur?
	9	Was the cohort follow-up long enough?