Dairy product consumption and gastric cancer risk: A meta-analysis

Table 3 Methodological quality of cohort studies included in this meta-analysis

Ref.	Representativeness of the exposed cohort	Selection of the non exposed cohort	Ascertainment of exposure	Outcome of interest not present at start of study	Control for important factors1	Assessment of outcome	Follow-up long enough for outcomes to occur2	Adequacy of follow-up of cohorts3	Total quality scores
Nomura et al[49], 1990	*	*	*	*	*	*	*	*	8
Kneller et al[50], 1991	*	*	*	*	*	*	*	*	8
Galanis et al[51], 1998	*	*	*	*	**	*	*	*	9
Ngoan et al[52], 2002	*	*	*	*	**	*	*	*	9
Khan et al[53], 2004	*	*	*	*	**	*	*	*	9
Tokui et al[54], 2005	*	*	*	*	*	*	*	*	8
Van der Pols et al[55], 2007	*	*	-	*	*	*	*	*	7
Pham et al[56], 2010	*	*	*	*	**	*	-	*	8
Buckland et al[57], 2010	*	*	*	*	*	*	*	*	8
Ko et al[58], 2013	*	*	*	*	**	*	*	*	9

¹A maximum of two stars could be awarded for this item. Studies that controlled for age received one start, whereas studies that controlled for smoking or drinking received an additional start;

²A cohort study with a follow-up time > 8 years was awarded one start;

³A cohort study with a follow-up rate > 70% was awarded one start.