Purpose
To develop a risk score for predicting treatment-requiring ROP (TR-ROP) as determined by study-certified ophthalmologists in the e-ROP study.
Design
Second Analyses of an observational cohort study.
Participants
Infants with birth weight <1251g who had at least one imaging session by 34 weeks of postmenstrual age (PMA) and at least one subsequent ROP examination for determining TR-ROP by study-certified ophthalmologists.
Methods
Non-physician trained readers evaluated wide-field retinal image sets for characteristics of ROP, pre-plus/plus disease and retinal hemorrhage. Risk score points for predicting TR-ROP were derived from the regression coefficients of significant predictors in a multivariate logistic regression model.
Results
Among 771 infants, 85 (11.0%) developed TR-ROP. In a multivariate model, significant predictors [odds ratio (95% confidence interval)] for TR-ROP were: gestational age (GA) [5.7 (1.7 – 18.9) for ≤25 vs. ≥28 weeks], need for respiratory support [7.0 (1.3 – 37.1) for high frequency oscillatory ventilation vs. no respiratory support], slow weight gain [2.4 (1.2 – 4.6) for weight gain ≤12g/day vs. >15g/day], and image findings at the first image session including: number of quadrants with pre-plus [3.8 (1.5 – 9.7) for 4 pre-plus quadrants vs. no pre-plus], stage and zone of ROP [4.7 (2.1 – 11.8) for stage 1–2 zone I, 5.9 (2.1 – 16.6) for stage 3 zone I vs. no ROP], and presence of blot hemorrhage [3.1 (1.4 – 6.7)]. Image findings predicted TR-ROP better than GA (area under ROC curve [AUC] =0.82 vs. 0.75, p=0.03). The 22-point risk score derived from 6 significant predictors had a median of 4 points (range: 0 to 18). The risk of TR-ROP steadily increased with higher risk score (0% for 0 point, 1–8% for 1–5 points, 12–27% for 6–10 points, 43% for 11–13 points and 94% for 14 points or above), and predicted TR-ROP well (AUC=0.88, 95% CI: 0.85–0.92). Risk score ≥3 points for predicting TR-ROP had sensitivity 98.8%, specificity 40.1%, positive and negative predictive values of 17.0% and 99.6% respectively.
Conclusions
Image characteristics at 34 PMA weeks or earlier independently predict TR-ROP. If externally validated in other infants, risk score, calculated from image findings, GA, weight gain and respiratory support, enables early identification of infants in need of increased surveillance for TR-ROP.