Unseen Socioeconomic Factors Important in Retinopathy of Prematurity Risk Assessment

Alison Chu, MD

New findings suggest that when placed in the context of socioeconomic factors and gestational age, race and ethnicity were not associated with the diagnosis of retinopathy of prematurity (ROP).

Data show that after adjustments for factors including household income and insurance status, the association between race and ethnicity and gestational age was no longer significant.

“Thus, when assessing ROP risk, it is important to understand unseen socioeconomic factors that may be affecting maternal health and preterm birth and subsequently neonatal health to optimize health outcomes,” wrote study author Alison Chu, MD, Division of Neonatology and Developmental Biology, Department of Pediatrics, University of California, Los Angeles.

Chu and colleagues noted the growing awareness of racial and ethnic differences in health outcomes may be due to socioeconomic determinants of health. Thus, race and ethnicity should be considered as social factors, not strictly biological.

In the current retrospective cohort study, they explored how socioeconomic factors (income, health insurance status, race and ethnicity) are associated with the risk of ROP diagnosis and severity.

Data was collected from 4 hospitals in Los Angeles, with eligible criteria consistent with American Academy of Pediatric guidelines for ROP screening:

• Infants born at a gestational age of ≥30 weeks
• Birth weight <1500 g
• Gestational age at birth >30 weeks, but with an unstable clinical course

Participants were screened for ROP between January 2010 - December 2020. They were eligible if their record contained all relevant demographic and socioeconomic data, including race and ethnicity, health insurance status, and proxy household income.

The severity of ROP was determined using the individuals’ worst ROP examination with a classification system developed by the Early Treatment for Retinopathy of Prematurity Cooperative Group. Patients were classified as having no ROP, low-grade ROP, or type 1 ROP.

Of a total of 1267 infants screened for ROP, 1234 neonates had available demographic and socioeconomic data and met inclusion criteria. The study cohort had a median gestational age of 29 weeks and median birth weight of 1150 g.

Further, the cohort had a median proxy household income of $75,714 and 761 neonates (62%) had private health insurance. Data show 340 infants (28%) identified as Hispanic, 117 as non-Hispanic Asian (9%), 219 as non-Hispanic Black (18%) and 463 as non-Hispanic White (38%).

In the unadjusted model, race and ethnicity were associated with a diagnosis of ROP, including low-grade and type 1 ROP (P = .03). Investigators observed Hispanic neonates had 1.70 times the odds to be diagnosed with ROP (odds ratio [OR], 1.70; 95% CI, 1.20 - 2.42) when compared with non-Hispanic White neonates, while Black neonates had 1.49 times the odds (OR, 1.49; 95% CI, 0.98 - 2.27).

They found the associations with Hispanic ethnicity and more severe ROP were no longer observed when adjusted for gestational age and socioeconomic factors (OR, 1.12; 95% CI, 0.68 - 1.82 for ROP diagnosis and OR, 1.67; 95% CI, 0.80 - 3.52 for ROP severity).

In a fully adjusted model, lower gestational age was the primary predictor of ROP incidence (OR, 0.52; 95% CI, 0.48 - 0.57; P <.001). After adjustments for proxy socioeconomic status, race and ethnicity were no longer a significant predictor of gestational age (P = .40). However, lower household income was associated with lower gestational age (OR, 0.26; 95% CI, 0.09 - 0.43; P = .002).

“Future studies from other geographical areas with different health insurance practices would be beneficial to grow our understanding of how structural inequalities are associated with maternal-fetal health outcomes,” Chu concluded.

The study, “Association Between Social Determinants of Health and Retinopathy of Prematurity Outcomes,” was published in JAMA Ophthalmology.