Role of socio-economic factors in visual impairment and progression of diabetic retinopathy

Background To investigate the longitudinal associations between person-level and area-level socioeconomic status (PLSES and ALSES, respectively) with diabetic retinopathy (DR) and visual impairment (VI) in Asians with diabetes mellitus (DM). Methods In this population-based cohort study, we included 468 (39.4%) Malays and 721 (60.6%) Indians with DM, with a mean age (SD) of 58.9 (9.1) years; 50.6% were female and the mean follow-up duration was 6.2 (0.9) years. Individual PLSES parameters (education, monthly income and housing type) were quantified using questionnaires. ALSES was assessed using the Socioeconomic Disadvantage Index derived from Singapore's 2010 areal census (higher scores indicate greater disadvantage). Incident DR and VI were defined as absent at baseline but present at follow-up, while DR and VI progression were defined as a >= 1 step increase in severity category at follow-up. Modified Poisson regression analysis was used to determine the associations of PLSES and ALSES with incidence and progression of DR and VI, adjusting for relevant confounders. Results In multivariable models, per SD increase in ALSES score was associated with greater DR incidence (risk ratio (95% CI) 1.27 (1.13 to 1.44)), DR progression (1.10 (1.00 to 1.20)) and VI incidence (1.10 (1.04 to 1.16)), while lower PLSES variables were associated with increased DR (low income: 1.68 (1.21 to 2.34)) and VI (low income: 1.44 (1.13 to 1.83); <= 4 room housing: 2.00 (1.57 to 2.54)) incidence. Conclusions We found that both PLSES and ALSES variables were independently associated with DR incidence, progression and associated vision loss in Asians. Novel intervention strategies targeted at low socioeconomic status communities to decrease rates of DR and VI are warranted.