Health insurance enrollment and vision health in rural China: an epidemiological survey.

BACKGROUND: Vision health is an important aspect of health worldwide. Visual impairment (VI) is associated with poor quality of life and is usually more prevalent in rural areas. To help rural populations obtain vision care, health insurance policies have emerged throughout the world. However, some existing literatures show that health insurance enrollment's impact on the overall physical health of rural population has been minimal. Focusing on vision health among adults in rural China, our study aims to investigates the impact of health insurance on vision health, heterogeneity of the effect, and the moderating effect of health insurance enrollment on the impact of chronic physical diseases and basic eye diseases on vision health. METHODS: Primary data were collected through a nation-wide epidemiological survey of vision health conducted in rural China in 2018, with a sample size of 28,787 used in our statistical analysis. Instrumental variables regression and Heckman selection models were conducted to examine the impact of health insurance enrollment and reimbursement ratio adults' vision health outcomes. Subsample regressions by sex, age, education level, and whether with eye diseases were further conducted to explore the heterogeneity in our results. We then examined whether health insurance enrollment moderates the impact of chronic physical diseases and basic eye diseases on vision health through the method of introducing interaction terms. RESULTS: Participating in health insurance reduced the probability of VI by 2.15 %. The reimbursement rate increasing by 1 % point may reduce the probability of worsening VI by 6.12 %. Men (-0.0235, P = 0.0002) benefit more from insurance enrollment than women (-0.0201, P = 0.0082) with respect to vision health. From the young adult group to the oldest group, the marginal effect of health insurance increased from - 0.0068 (P = 0.0394) to -0.0753 (P < 0.0001). The marginal effect on VI was most significant in people with lower education levels and weakened with increased education levels. People with basic eye diseases (-0.0496, P = 0.0033) benefit more from participating insurance than the people without basic eye diseases (-0.0196, P = 0.0001) with respect to vision health. The moderating effects of health insurance enrollment on the impacts of cerebral infarction (-0.1225, P < 0.0001), diabetes (-0.0398, P = 0.0245), hyperlipidemia (-0.1364, P = 0.0271), mental illness (-0.1873, P = 0.0010), glaucoma (-0.1369, P = 0.0073), diabetic retinopathy (-0.1560, P = 0.0043), and retinal vein obstruction (-0.2018, P = 0.0155) on vision health were significantly negative. CONCLUSIONS: The results suggest that participation in health insurance and higher health insurance reimbursement ratios reduced the risk of VI in the sampled adults. Health insurance has the most significant effect in in vulnerable groups. Heath insurance enrollment moderates the impacts of several chronic physical and basic eye conditions on vision health. Our findings have potential implications for reforming health insurance policies to improve vision health conditions in rural areas of developing countries.

Impacts of heatwaves and cold spells on glaucoma in rural China: a national cross-sectional study.

China faces increasing health risks from climate change. The structure and function of the eye and vision were affected by extreme heat and cold. The study aimed to evaluate the impacts of heatwaves and cold spells on glaucoma. A national cross-sectional study of the Rural Epidemiology for Glaucoma (REG-China) was conducted in ten provinces of China, and 36,081 adults aged 40 years or more were included. Glaucoma signs were assessed via a standard examination. A total of 15 heatwave definitions, based on intensity (95th to 99th percentiles of temperature distribution) and duration (≥2 days, 3 days, and 4 days), were used to quantify heatwave effects, and 6 cold spell definitions were defined based on threshold temperature percentile (5th and 10th) and duration (3 days, 5 days, and 9 days). Multivariable-adjusted logistic regression models paired with interaction analysis were performed to investigate the impacts of heatwaves and cold spells on glaucoma, and the dose-response relationships were assessed using a restricted cubic spline (RCS) model. Subgroup analysis was conducted stratified by gender, age, smoking status, occupation, and family history of glaucoma. The overall prevalence of glaucoma was 2.1% (95% CI 1.94-2.25%). Higher heatwaves were significantly correlated with higher OR of glaucoma, with the OR (95% CI) ranging from 1.014 (1.009, 1.018) to 1.090 (1.065, 1.115) by different definitions. Glaucoma was affected by heatwaves more strongly than by cold spells. The effects of both heatwaves and cold spells were higher in males than females and in smokers than nonsmokers. These results of the present study evoked the attention of prospective research to elucidate the relationship between extreme temperatures and eye diseases.

Glaucoma in rural China (the Rural Epidemiology for Glaucoma in China (REG-China)): a national cross-sectional study.

OBJECTIVE: This study aimed to investigate the prevalence of glaucoma with associated factors in the rural populations of 10 provinces in China. DESIGN: A population-based cross-sectional study. METHODS: All participants aged 6 years or older from 10 provinces completed visual acuity testing, slit-lamp examination, ophthalmoscopy and non-contact tonometry. Glaucoma suspects underwent fundus photography, Goldmann applanation tonometry, visual field testing and gonioscopy. Glaucoma was determined according to the International Society of Geographical and Epidemiological Ophthalmology classification scheme. Associations of demographics and medical factors with glaucoma were assessed using multiple logistic regression models. RESULTS: From June 2017 to October 2018, 48 398 of 52 041 participants were included in the final analyses. The age-standardised prevalence of glaucoma was 1.7% (95% CI 1.55% to 1.78%) among the participants older than 6 years, which was 2.1% (95% CI 1.93% to 2.23%) in participants aged over 40 years. The constituent ratios of glaucoma were: 44.4% primary angle-closure glaucoma (PACG), 34.7% primary open-angle glaucoma, 2.6% congenital glaucoma and 18.3% other types of glaucoma. Increasing age, smoking, cerebral stroke, type 2 diabetes, higher education (college or more) and higher personal income were significant risk factors for PACG. The unilateral and bilateral blindness rates in the entire study population were 4.692% and 1.068%, respectively. A family history of glaucoma was a significant risk factor for the prevalence of glaucoma and blindness in at least one eye. CONCLUSIONS: Rural populations have a high prevalence of glaucoma, which should be included in chronic disease management programmes in China for long-term care.

The association between long-term exposure to ambient fine particulate matter and glaucoma: A nation-wide epidemiological study among Chinese adults.

BACKGROUND: A growing body of evidence has confirmed the association between fine particulate matter (PM2.5) and ocular diseases, but little is known on the effect of long-term PM2.5 exposure on glaucoma. METHODS: A national cross-sectional study of the Rural Epidemiology for Glaucoma was conducted in 10 provinces of China, and 33,701 adults aged 40 years or more were included. A satellite-based model at 1-km resolution level was used to estimate PM2.5 concentrations which were assigned to each participant according to geocoded home addresses. Logistic regression model was performed to investigate associations of long-term PM2.5 exposure with glaucoma and its subtypes. RESULTS: Estimated PM2.5 concentrations ranged from 28.0 to 96.4 µg/m3. For each 10 µg/m3 increment in PM2.5, the adjusted odds ratios (ORs) were 1.07 (95% CI: 1.00-1.15) and 1.14 (95% CI: 1.02-1.26) for glaucoma and primary angle-closure glaucoma (PACG), respectively. A positive but non-significant association (OR = 1.05, 95% CI: 0.92-1.18) was detected between long-term exposure to PM2.5 and odds of primary open-angle glaucoma. The middle aged residents and non-smokers were more sensitive to the adverse effects of PM2.5. CONCLUSIONS: Long-term PM2.5 exposure was associated with glaucoma and PACG in Chinese adults, which provided new insights on adverse ophthalmic effect of PM2.5.

Association between long-term exposure to fine particulate matter and diabetic retinopathy among diabetic patients: A national cross-sectional study in China.

BACKGROUND: While the relationship between ambient air pollution and diabetes mellitus has recently been reported, data on the association between fine particulate matter (PM2.5) and diabetic complications are limited, especially in microvascular diseases such as diabetic retinopathy. OBJECTIVES: To investigate the associations between long-term exposure to PM2.5 and the prevalence of diabetic retinopathy in adult diabetic patients in rural China. METHODS: The study population was based on the Rural Epidemiology for Glaucoma in China (REG-China), a national cross-sectional survey conducted in rural China. This analysis selected diabetic patients with or without diabetic retinopathy. A satellite-based spatiotemporal model was used to estimate personal PM2.5 exposure. Logistic regression models were used to investigate the effect of long-term PM2.5 exposure on diabetic retinopathy. RESULTS: The analysis included 3111 diabetic participants, 329 of whom were diagnosed with diabetic retinopathy. The median level of exposure to PM2.5 from 2000 to2016 was 59.9 µg/m3. For each 10 µg/m3 increase in PM2.5, the adjusted odds ratio (95% confidence interval) for diabetic retinopathy was 1.41 (1.27, 1.57). In subgroup analyses, the effect of PM2.5 on diabetic retinopathy was significantly stronger in participants who self-reported alcohol consumption. CONCLUSION: These findings suggest that long-term exposure to high PM2.5 was associated with the risk of diabetic retinopathy among diabetic patients in rural China.

[A national survey on low vision and blindness of 0 - 6 years old children in China].

OBJECTIVE: To get the prevalence of visual impairment of children in China. The national survey of low vision and blindness of 0 approximately 6 years old children was conducted in China in 2001. METHOD: Stratified, random, cluster, systematic sampling was used to select 60 124 subjects from 360 clusters from 6 provinces in China. The trained doctors examined every individual. RESULT: 64 subjects were defined as visual impairment among the total 60 124 participated subjects in the survey. The total prevalence of visual impairment is 1.1 per thousand. The 20 subjects is blindness and the prevalence is 0.33 per thousand. 44 subjects is low vision and the prevalence is 0.73 per thousand. The major causes of visual impairment are amblyopia (32.8%), retinal and optic nerve diseases (15.6%), congenital cataract (14.1%) and congenital glaucoma (6.3%). CONCLUSION: The prevalence of blindness is close the level of developed country. Amblyopia is the leading cause of all visual impairment. Most causes of visual impairment, amblyopia and congenital cataract are curable.