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Original Investigation
April 2018

Validation of the Colorado Retinopathy of Prematurity Screening Model

Author Affiliations
  • 1Department of Ophthalmology, University of Colorado School of Medicine, Aurora
  • 2Scheie Eye Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia
  • 3Division of Ophthalmology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
JAMA Ophthalmol. 2018;136(4):409-416. doi:10.1001/jamaophthalmol.2018.0376
Key Points

Question  What is the sensitivity and specificity of the Colorado Retinopathy of Prematurity (CO-ROP) model for predicting severe ROP in a large, diverse cohort of premature infants?

Findings  In this validation study, the CO-ROP model demonstrated high but not 100% sensitivity for severe ROP and missed infants who might require treatment. Most of the infants not predicted by the CO-ROP model had obvious deviation in expected weight trajectories or nonphysiologic weight gain.

Meaning  These findings suggest that the CO-ROP model needs to be revised before considering implementation into clinical practice.

Abstract

Importance  The Colorado Retinopathy of Prematurity (CO-ROP) model uses birth weight, gestational age, and weight gain at the first month of life (WG-28) to predict risk of severe retinopathy of prematurity (ROP). In previous validation studies, the model performed very well, predicting virtually all cases of severe ROP and potentially reducing the number of infants who need ROP examinations, warranting validation in a larger, more diverse population.

Objective  To validate the performance of the CO-ROP model in a large multicenter cohort.

Design, Setting, Participants  This study is a secondary analysis of data from the Postnatal Growth and Retinopathy of Prematurity (G-ROP) Study, a retrospective multicenter cohort study conducted in 29 hospitals in the United States and Canada between January 2006 and June 2012 of 6351 premature infants who received ROP examinations.

Main Outcomes and Measures  Sensitivity and specificity for severe (early treatment of ROP [ETROP] type 1 or 2) ROP, and reduction in infants receiving examinations. The CO-ROP model was applied to the infants in the G-ROP data set with all 3 data points (infants would have received examinations if they met all 3 criteria: birth weight, <1501 g; gestational age, <30 weeks; and WG-28, <650 g). Infants missing WG-28 information were included in a secondary analysis in which WG-28 was considered fewer than 650 g.

Results  Of 7438 infants in the G-ROP study, 3575 (48.1%) were girls, and maternal race/ethnicity was 2310 (31.1%) African American, 3615 (48.6%) white, 233 (3.1%) Asian, 40 (0.52%) American Indian/Alaskan Native, and 93 (1.3%) Pacific Islander. In the study cohort, 747 infants (11.8%) had type 1 or 2 ROP, 2068 (32.6%) had lower-grade ROP, and 3536 (55.6%) had no ROP. The CO-ROP model had a sensitivity of 96.9% (95% CI, 95.4%-97.9%) and a specificity of 40.9% (95% CI, 39.3%-42.5%). It missed 23 (3.1%) infants who developed severe ROP. The CO-ROP model would have reduced the number of infants who received examinations by 26.1% (95% CI, 25.0%-27.2%).

Conclusions and Relevance  The CO-ROP model demonstrated high but not 100% sensitivity for severe ROP and missed infants who might require treatment in this large validation cohort. The model requires all 3 criteria to be met to signal a need for examinations, but some infants with a birth weight or gestational age above the thresholds developed severe ROP. Most of these infants who were not detected by the CO-ROP model had obvious deviation in expected weight trajectories or nonphysiologic weight gain. These findings suggest that the CO-ROP model needs to be revised before considering implementation into clinical practice.

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