Rationale, design, methodology, and baseline data of a population-based study in rural China: the Handan Eye Study

To describe the rationale, design, methodology and baseline characteristics of the Handan Eye Study (HES), a population-based study to determine the prevalence and impact of visual impairment and major ocular diseases in Chinese adults living in a rural region north China.

Population-based, cross-sectional study. 6830 Han people aged 30 years and older from 13 villages of Yongnian County, Handan city, Hebei province, China were recruited. The interviews covered demographic, behavioral, and ocular risk factors as well as health-related and vision-related quality of life. Ocular examination included measurement of visual acuity (VA), intraocular pressure, anterior and posterior segment examinations, visual field testing, and anterior segment, fundus and optic disc photography/imaging. Physical examination included measurement of height and weight, blood pressure, electrocardiogram, fasting blood glucose, lipid levels, urea nitrogen and creatinine as well as tests of physical function including walking speed.

Of the 7557 individuals eligible for the Handan Eye Study (HES), 6830 (90.4%) subjects participated the study. The majority of participants were female (53.6%), the average (+/- standard deviation) age was 52.3 (+/- 12.3) years, and 100% were self-identified Han people. In contrast to the non-participants, those who participated were more likely to be female, elderly, married, and had more years of education (P < 0.05).

The HES successfully examined over 90% of eligible Han Chinese adults aged 30 and older from a rural region of north China. Results from the HES will provide key information about the prevalence, risk factors, impact, and trends of ocular disease in rural regions of China.