Abstract
Purpose :
To estimate the incidence of severe retinopathy of prematurity (ROP) for infants screened at the University of Puerto Rico Pediatric Hospital (HOPU) and, using our cohort's baseline characteristics, to calculate the adjusted odds ratios (OR) for developing severe ROP.
Methods :
Cross-sectional study of all infants born in Puerto Rico (PR) and screened for severe ROP between January 1, 2006 and December 31, 2006. Infants were either born at HOPU (inborns) or were transferred to HOPU from any of 19 Neonatal Intensive Care Units (outborns). According to the American Academy of Pediatrics guidelines from 2006, we included only infants that survived to 31 weeks chronological age and had a birth weight (BW) of less than 1500 grams (g) or a gestational age (GA) of 30 weeks (wks) or less. Severe ROP was defined by the Early Treatment for ROP Study (ETROP Type 1) for which prompt laser application had to be considered. This included zone 1 any stage ROP with plus disease, zone 1 stage 3 ROP with or without plus disease, or zone 2 stage 2 or stage 3 ROP with plus disease.Chi-square analysis was used to compare categorical variables. Mann-Whitney test was used to compare numerical variables that were not normally distributed. Multivariate logistic regression was used to predict risk factors for severe ROP. For all analyses, P values of less than 0.05 were considered statistically significant.
Results :
Severe ROP was diagnosed in 29.6% of 159 examined infants, including 54.7% outborn infants and 17.0% of inborns (P <0.001). No significant difference was observed between outborn and inborn infants with severe disease according to BW (median, 880 versus 920 g; P=0.177), GA (median, 26.0 versus 27.0 wks; P=0.083) and gender (male, 51.7% versus 51.1%; P= 0.529). Multivariate regression model revealed that a short GA (≤ 28 wks) was strongly associated with the development of severe ROP (OR, 15.5; 95% CI 1.7-145.4; P=0.02). Also, infants born at outlying hospitals (OR, 1.63; 95% CI 1.46-8.73; P=0.01) and male infants (OR, 1.89; 95% CI 1.40-10.07; P=0.01) were more likely to develop severe ROP.
Conclusions :
Almost one third of screened infants had severe ROP. Particularly, outborn infants were more likely than inborns to have severe ROP despite having no significant difference according to GA, BW and gender. Future studies should investigate why outborn infants had a higher incidence of severe ROP, and if neonatal care was the critical issue.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.