Population study identifies length of stay, gestational weight as risk factors for ROP

Am J Ophthalmol. 2009;148(3):451-458.

Low birth weight combined with a prolonged hospital stay is a risk factor for the development of retinopathy of prematurity, according to a large, population-based study.

In a population of 34 million live births recorded in the National Inpatient Sample between 1997 and 2005, 58,722 newborns were identified with ROP through ICD-9 codes for a total incidence of 0.17%. In a group of premature infants with a length of stay longer than 28 days, 15.58% were diagnosed with ROP.

For any given birth weight, patients with ROP had a longer length of stay in the hospital than patients without ROP. As well, patients with lower birth weight had an increased risk of an ROP diagnosis, and the odds ratio for an ROP diagnosis decreased in patients closer to 2,500 g, which was used as a comparison group in the study.

The study also identified several comorbidities that either increased the risk or conferred a protective effect. Infants with ROP had a higher risk of having a respiratory condition, chronic respiratory disease, fetal hemorrhage, intraventricular hemorrhage and blood transfer. However, infants with ROP and a hospital stay longer than 28 days had a lower association with hypoxia, necrotizing enterocolitis and hemolytic disease, according to the study.