. 2017 Jul 3;10:3261–3276. doi: 10.2147/OTT.S135593

Table 4.

Quality assessment of included studies according to NOS

Studies		Selection				Comparability	Outcome			Total
First author	Year	A	B	C	D	E	F	G	H	score
Kjellman et al¹	2003	*	*	*			*	*	*	6
Feng and Wang⁶²	2015	*	*	*			*	*	*	6
Ito et al¹²	2010	*	*	*			*	*	*	6
Jovanovic et al³²	2015	*	*	*			*	*	*	6
Gnemmi et al¹⁴	2014	*	*	*		*	*	*	*	7
Miyauchi et al²²	2013	*	*	*			*	*		5
Chen et al²⁰	2011	*	*	*			*	*	*	6
Wang et al³³	1996	*	*	*			*	*	*	6
Tisell et al²⁶	2003	*	*	*			*	*	*	6

Notes: A: representative of the exposed cohort; B: selection of the nonexposed cohort; C: ascertainment of exposure; D: demonstration that outcome of interest was not present at the start of study; E: comparability of cohorts on the basis of the design or analysis; F: assessment of outcome; G: adequacy of follow-up for outcomes to occur (≥2 years or outcomes occurred in all patients); H: adequacy of follow-up of cohorts (follow-up rate ≥75%).

Abbreviation: NOS, Newcastle–Ottawa scale.