AA Yekta, A Fotouhi, M Khabazkhoob, H … - Ophthalmic …, 2009 - informahealthcare.com Purpose: To determine the prevalence rates of refractive errors in elderly people in Mashhad, Iran.
Methods: In a cross-sectional study with a cluster sampling method, the sample population was
selected proportionate to the total ... Related articles - All 5 versions
SA Schellini, SR Durkin, E Hoyama, F Hirai, R … - BMC …, 2009 - biomedcentral.com A population-based cross-sectional study was conducted involving a random start point and then
systematic sampling of an urban Brazilian population in the city of Botucatu. There were
approximately 3 300 individuals ... Related articles - Cached - All 6 versions