Table 38: Internal Validity Characteristics.

Study	Sampling Method	Sample Size Calculation a Prior	Standardized measurements	Reliability Assessments
Blue Mountains Study Australia (56)	A total sample of a population from 2 postcode areas west of Sydney.	Not reported	Yes	Inter and Intra-rater reliability
Los Angeles Latino Eye Study (55)	A total sample of a population in 6 census tracts in and around the city of La Puente, Los Angeles County	Yes	Yes	Inter and intra rater reliability
Atherosclerosis Risk in Communities (ARIC) Study (57)	Probability Sample		Yes	Inter rater and intra rater reliability
Multi-ethnic Study of Atherosclerosis (MESA) (58)	Probability Sampling	Yes	Yes	Inter and intra-rater reliability was assessed among the 9 graders on a random subset of images of 25 eyes