Validity and feasibility of a self-administered home vision examination in Yueqing, China: a cross-sectional study

OBJECTIVE: To investigate the validity and feasibility of a self-administered home vision examination programme in China. DESIGN: Cross-sectional study. SETTING: Yueqing, China. PARTICIPANTS: A two-stage convenience sampling procedure was used to randomly select 600 households from 30 communities participating in the Yueqing Eye Study (YES). The aim of YES is to encourage home-based vision screening, reporting of visual acuity (VA) annually through social media and encouraging people to attend follow-up clinic appointments as a way to improve eye care access for adults with VA ≤+0.5 log of the minimum angle of resolution (logMAR). INTERVENTIONS: Household screeners (one per household) who tested other family members’ VA completed a questionnaire on family structure, demographic information and knowledge about screening procedures. Other family members then underwent confirmatory VA testing by researchers. OUTCOME MEASURES: The completion rate of home-based VA screening, its sensitivity and specificity were used to evaluate validity. Factors that determined whether families participated in the self-VA screening were used to evaluate feasibility. RESULTS: 345 (66%) of the 523 (87.2%) households with valid data form their home-based vision examinations also were retested by researchers. There was no statistically significant difference in scores on the family-administerd or researcher-administerd VA test (VA≤+0.5 logMAR, p=0.607; VA >+0.5 logMAR, p=0.612). The sensitivity and specificity of home-based vision screening were 80.5% (95% CI 70.2% to 86.9%) and 95.1% (95% CI 92.6% to 96.8%), respectively. 14.7% (77/523) of tested respondents had VA ≤+0.5 logMAR. Predictors of performing home screening for VA remaining in regression models included higher economic status (‘fair and above’ vs ‘poor’: OR 1.74; 95% CI 1.08 to 2.76; p=0.022), age (<45 years vs ≥45 years: OR 0.46; 95% CI 0.25 to 0.85; p=0.014) and living in a nuclear (OR 5.17; 95% CI 2.86 to 9.36; p<0.001) or extended family (OR 8.37; 95% CI 4.93 to 14.20; p<0.001). CONCLUSION: Self-administered home vision screening is reliable and highly accepted by Chinese adults.