Association between social vulnerability index and cataract surgery care in medicare beneficiaries: a retrospective cohort study
TL;DR
Higher SVI is associated with disparities in receipt of cataract surgery among Medicare beneficiaries, which may be mediated by delays in cataract diagnosis, and reducing SDOH-related barriers to timely diagnosis in under-resourced areas could shorten the overall time to cataract surgery in this population.
Abstract
Social vulnerability index (SVI) has been used as a surrogate measure to assess social determinants of health (SDOH) when conducting health disparities research, but the impact of SVI on the timing, receipt, and outcomes of cataract care in a nationally representative population of patients is unknown. A retrospective observational cohort study of Medicare fee-for-service beneficiaries aged 66 + in 2014 without a prior diagnosis of cataract disease was conducted to determine who went on to develop cataract disease and undergo cataract surgery between 2014 and 2021. A Fine and Gray sub-distribution hazard model was used to determine the association between SVI quartile, time to diagnosis and time to cataract surgery. Logistic regression was used to assess the association between SVI quartile and the incidence of ophthalmic complications. Among 170,778 Medicare beneficiaries aged 66 + years of age at the start of the study period, 50.2% identified as female, 7.0% Black, 4.4% Hispanic, and 80.9% White. Fewer beneficiaries residing in high SVI (higher vulnerability) regions were diagnosed with cataracts (Quartile 4 55.9% vs. Q1 67.1%, p < 0.001) and underwent cataract surgery (Q4 19.4% vs. Q1 21.1%, p < 0.001) compared to beneficiaries in low SVI regions. After adjusting for patient demographics, overall health and frailty status, and health systemic characteristics including region, urban/rural location and number of ophthalmologists per capita, patients residing in higher SVI areas had lower rates of diagnosis (Q2 HR: 0.92 95% CI (0.91, 0.94); Q3 0.86 (0.84, 0.87); Q4: 0.78 (0.77, 0.80), reference=Q1) and cataract surgery (Q3 HR: 0.95, 95% CI (0.92, 0.98) and Q4: 0.90 (0.87, 0.93), respectively, reference=Q1). However, once a diagnosis was made, patients residing in higher SVI regions had higher rates of cataract surgery (Q2 HR: 1.04 (1.01, 1.07); Q3: 1.06 (1.03, 1.09); and Q4: 1.08 (1.05, 1.12), respectively, reference=Q1). There was no association between SVI and ophthalmic complications. Higher SVI is associated with disparities in receipt of cataract surgery among Medicare beneficiaries, which may be mediated by delays in cataract diagnosis. Reducing SDOH-related barriers to timely diagnosis in under-resourced areas could shorten the overall time to cataract surgery in this population.