Incidence of Retinopathy of Prematurity Nearly Doubled in US From 2003 to 2019

Christina Y. Weng, MD, MBA

Credit: Baylor College of Medicine

The overall incidence of retinopathy of prematurity (ROP) among infants born premature almost doubled between 2003 and 2019, particularly in traditionally underserved populations, according to new research.¹

Investigators from the Baylor College of Medicine, led by Chistina Y. Weng, MD, MBA, found the incidence to be persistently higher over time, with a relatively greater increase in infants who were indicated in the database as Black, born in lower-income households, or born in the South or Midwest.

“Although causation cannot be determined from this database study, these trends emphasize that ROP is a growing problem in the US and may be disproportionately affecting certain subpopulations,” investigators wrote.

Recent evidence suggests that ROP incidence in the US continues to rise and another epidemic may be on the horizon. To better investigate the trends, Weng and colleagues used the National Healthcare Cost and Utilization Project (HCUP) Kids’ Inpatient Databases (KIDs) from 2003 to 2019 to analyze ROP incidence in the US across database-reported sex, race and ethnicity, income level, and geographic regions.

The nationwide databases are produced every 3 years and each version contains clinical and nonclinical information from an estimated 7 million pediatric hospitalizations from over 4000 hospitals in the United States. Being the largest pediatric inpatient care databases in the country, KIDs are designed to generate national estimates of healthcare trends.

Newborn infants with relevant International Classification of Diseases (ICD), Ninth Revision, or Tenth Revision codes designating low birth weight (≤1500 g) or premature birth (≤36 weeks gestational age) were considered ROP candidates. Those with ROP younger than 1 year were additionally identified directly from KIDs using relevant ICD codes.

The study created key subpopulations based on database-reported race and ethnicity, income, sex, region, and metropolitan status. For each subpopulation, investigators calculated incidences among ROP candidates and all newborn births. Weng and colleagues used x2 tests independent to determine whether incidences varied by year or across subpopulations.

Across the 16 years of study, 23,187,683 newborn infants were identified and the study included 125,212 ROP discharges (64,715 [51.7%] male infants; female infants [48.3%]). Data showed the incidence of ROP among all newborn births increased significantly from 0.3% (n = 11.720 of 3,930,094) in 2003 to 0.76% (n = 27,160 of 3,588,465) in 2019, representing a 139% relative increase in ROP incidence (P <.001).

Moreover, the analysis showed the proportion of ROP incidence among ROP candidates also increased significantly from 4.4% (n = 11,720 of 265,650) in 2003 to 8.1% (n = 27,160 of 336,117) in 2019, which represented an 86% relative increase (P <.001). Weng and colleagues noted ROP incidence increased across all races and ethnicities between 2003 and 2019.

In most years, investigators found those who were classified as Black, Hispanic, or other had higher ROP incidences than those classified as Asian/Pacific Islander, Native American, or White. Premature Black infants experienced the largest increase from 5.8% to 11.6% (P <.001), at a 2.71% greater increase (95% CI, 2.56 - 2.87; P <.001) compared to other groups. Hispanic infants experienced the second largest increase from 4.6% to 8.2% (P <.001), relative to other groups (–0.16%; 95% CI, –0.29% to –0.03%; P = .02).

Additionally, from 2003 to 2019, ROP incidence increased in all geographic regions. The analysis showed the Southern US experienced the greatest proportional growth of ROP diagnoses, with an increase from 3.7% to 8.3% (P<.001), relative to other groups (1.61%; 95% CI, 1.51 - 1.71; P <.001). Moreover, ROP incidence increased in all urban regions and decreased in rural ones between 2003 and 2019, according to the analysis.

Between 2003 and 2019, data showed ROP incidence increased in all median household income quartiles. Patients from the lowest quartile experienced an 86% relative increase in ROP incidence between 2003 to 2019, from 4.9% to 9.0% (P <.001).

Weng and colleagues indicated racial and ethnic disparities, low ROP awareness, and inadequate screening may serve as potential reasons for health inequalities in certain subpopulations. Limited access to care, due to geography or income, can further burden underserved groups.

“Access to both the expertise and resources necessary for ROP screening and treatment is not equitably distributed across the US, and populations facing greater barriers to care are also often the groups likely to be most affected by ROP,” investigators wrote.

References

1. Bhatnagar A, Skrehot HC, Bhatt A, Herce H, Weng CY. Epidemiology of Retinopathy of Prematurity in the US From 2003 to 2019. JAMA Ophthalmol. Published online April 13, 2023. doi:10.1001/jamaophthalmol.2023.0809