Table 3. Assessment of study quality.

Published year	study	Quality indicators from Newcastle-Ottawa Scale*
		1	2	3	4	5A	5B	6	7	8
Case-control studies
2005a	Hageman et al. [19]	Yes	Yes	No	Yes	Yes	No	No	Yes	No
2005b	Hageman et al. [19]	Yes	Yes	No	Yes	Yes	No	No	Yes	No
2006	Chen et al. [20]	Yes	Yes	No	Yes	No	Yes	No	Yes	No
2006	Fuse et al. [21]	Yes	Yes	No	Yes	No	No	No	Yes	No
2007	Mori et al. [22]	Yes	Yes	No	Yes	Yes	Yes	No	Yes	No
2008	Kim et al. [23]	Yes	Yes	No	Yes	Yes	Yes	No	Yes	No
2008	Lee et al. [24]	Yes	Yes	No	Yes	No	No	No	Yes	No
2009	Bergeron et al. [26]	Yes	Yes	Yes	Yes	Yes	Yes	No	Yes	No
2009	Goto et al. [27]	Yes	Yes	No	Yes	Yes	No	No	Yes	No
2010	Hayashi et al. [28]	Yes	Yes	Yes	Yes	No	No	No	Yes	No
2010	Hecker et al. [29]	Yes	Yes	No	Yes	No	No	No	Yes	No
2010	Liu et al. [30]	Yes	Yes	No	Yes	Yes	No	No	Yes	No
2010	Yang et al. [31]	Yes	Yes	No	Yes	Yes	No	No	Yes	No
2011	Tanaka et al. [32]	Yes	Yes	No	Yes	Yes	No	No	Yes	No

Cohort
2008	Xing et al. [25]	Yes	Yes	Yes	Yes	No	No	No	Yes	No

*For case-control studies, 1, indicates cases independently validated; 2, cases are representative of population; 3, community controls; 4, controls have no history of AMD; 5A, study controls for age; 5B, study controls for additional factor(s); 6, ascertainment of exposure by blinded interview or record; 7, same method of ascertainment used for cases and controls; and 8, nonresponse rate the same for cases and controls. For cohort studies, 1 indicates exposed cohort truly representative; 2, nonexposed cohort drawn from the same community; 3, ascertainment of exposure; 4, outcome of interest not present at start; 5A, cohorts comparable on basis of age; 5B, cohorts comparable on other factor(s); 6, quality of outcome assessment; 7, follow-up long enough for outcomes to occur; and 8, complete accounting for cohorts. 2005^a=Hageman et al.'s study in Iowa cohort; 2005^b=Hageman et al.'s study in Columbia cohort.