ROP Incidence Increased in Premature Infants

Black and Hispanic children were found to be especially vulnerable to retinopathy of prematurity (ROP), which has increased in infants from 2003 to 2019, according to a new study published in JAMA Ophthalmology. Researchers also found that infants in the areas of lowest income in the country had the highest proportional incidence of ROP.

ROP affects premature and low-birth-weight infants, which can lead to vision impairment and blindness in the child. Abnormal development of retinal blood vessels is the primary cause of ROP. Its incidence has increased due to unmonitored supplemental oxygen, neonatal care advancements, and higher survival rates for premature infants. This current study used the National Healthcare Cost and Utilization Project (HCUP) Kids’ Inpatient Databases (KIDs) to analyze the incidence of ROP in the United States from 2003 to 2019 across racial groups, income groups, and geographic regions.

Data for this study were taken from the KIDs, which contained data on pediatric patients in the United States and are meant to estimate health care trends. The KIDS database is produced every 3 years, which gave the researchers data from 2003, 2006, 2009, 2012, 2016, and 2019 to work with.

Patients who were important to this study were identified using International Classification of Diseases, Ninth Revision (ICD-9) and Tenth Revision (ICD-10) codes. Newborns who had low birth weight or were premature were considered ROP candidates in this study. Infants with ROP who were younger than 1 year were also identified using ICD codes. Racial and ethnic categories, median household income (MHI), and region were all taken from the KIDS database.

There were 125,212 discharges identified in the database, of which 48.3% were female. A total of 36.4% were White, 24.1% were Black, 16.5% were Hispanic, 3.3% were Asian/Pacific Islander, 0.5% were Native American, and 6.7% identified as other. Most of the patients with ROP were from urban hospitals, with 42.0% located in the urban South and 15.1% located in the urban North. A total of 32.6% were born in areas with the lowest MHI quartile and 18.3% were born to parents living in areas of the highest MHI quartile.

Infants with ROP were found to more likely be female (odds ratio [OR], 1.05; 95% CI, 1.03-1.07), be Black (OR, 1.72; 95% CI, 1.70-1.74) or Hispanic (OR, 1.05; 95% CI, 1.03-1.07), or live in the urban South (OR, 1.21; 95% CI, 1.20-1.23) or urban Midwest (OR, 1.18; 95% CI, 1.16-1.20). Infants from areas with lower MHIs also had higher odds of being diagnosed with ROP.

Incidence of ROP increased from 0.3% in 2003 to 0.76% in 2019 in all newborn infants. ROP candidates also had an increase in ROP incidence, from 4.4% in 2003 to 8.1% in 2019. This increase was seen across all races and ethnicities, but Black, Hispanic, and other infants had higher incidences. Incidence of ROP in Black infants increased from 5.8% in 2003 to 11.6% in 2019. Incidence of ROP in Hispanic infants increased from 4.6% in 2003 to 8.2% in 2019; White infants saw an increase from 3.8% to 6.7%.

ROP incidence also increased in all geographic regions. Incidence of ROP increased from 3.7% to 8.3% in the South, 4.9% to 8.9% in the Midwest, 5.4% to 8.2% in the North, and 4.6% to 6.8% in the West. All urban regions saw an increase in incidence rate whereas rural areas saw a decrease. The Northeastern, Midwestern, Southern, and Western urban areas had increases in ROP incidence of 50%, 91%, 123%, and 46%, respectively, whereas the corresponding rural areas had decreases of 18%, 73%, 32%, and 36%.

The lowest MHI quartile saw an increase in the rate of ROP, going from 4.9% in 2003 to 9.0% in 2019. The second-lowest quartile also had an increase from 4.6% to 8.2%.

The study is limited to the data available in KIDs, which do not include data from outside of the hospital setting. These databases track discharges rather than patients, which could lead to counting a child more than once. Databases are also subject to missing data, which could influence the results.

The researchers concluded that the overall incidence of ROP had doubled from 2003 to 2019 in premature infants, which could lead to medical and economic consequences for the health care system in the United States.

Reference

Bhatnagar A, Skrehot HC, Bhatt A, Herce H, Weng CY. Epidemiology of retinopathy of prematurity in the US from 2003 to 2009. JAMA Ophthalmol. Published online April 13, 2023. doi:10.1001/jamaophthalmol.2023.0809