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<h5 class="section-title" id="d7289247e407">Question</h5>
<p id="d7289247e409">Can the CHOP ROP model be validated in a multicenter cohort large
enough to obtain
a precise estimate of the model’s sensitivity for treatment-requiring retinopathy
of prematurity?
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<h5 class="section-title" id="d7289247e412">Findings</h5>
<p id="d7289247e414">In this secondary analysis of data from the Postnatal Growth
and Retinopathy of Prematurity
Study of 7483 premature infants at risk for retinopathy of prematurity, the original
CHOP ROP model correctly predicted 452 of 459 infants with type 1 retinopathy of prematurity,
reducing the number of infants requiring examinations by 34.3% if only high-risk infants
received examinations.
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<h5 class="section-title" id="d7289247e417">Meaning</h5>
<p id="d7289247e419">These results suggest that the CHOP ROP model has high but not
100% sensitivity and
may be better used to reduce examination frequency.
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<h5 class="section-title" id="d7289247e423">Importance</h5>
<p id="d7289247e425">The Children's Hospital of Philadelphia Retinopathy of Prematurity
(CHOP ROP) model
uses birth weight (BW), gestational age at birth (GA), and weight gain rate to predict
the risk of severe retinopathy of prematurity (ROP). In a model development study,
it predicted all infants requiring treatment, while greatly reducing the number of
examinations compared with current screening guidelines.
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<h5 class="section-title" id="d7289247e428">Objective</h5>
<p id="d7289247e430">To validate the CHOP ROP model in a multicenter cohort that is
large enough to obtain
a precise estimate of the model’s sensitivity for treatment-requiring ROP.
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<h5 class="section-title" id="d7289247e433">Design, Setting, and Participants</h5>
<p id="d7289247e435">This investigation was a secondary analysis of data from the
Postnatal Growth and
Retinopathy of Prematurity (G-ROP) Study. The setting was 30 hospitals in the United
States and Canada between January 1, 2006, and June 30, 2012. The dates of analysis
were September 28 to October 5, 2015. Participants were premature infants at risk
for ROP with a known ROP outcome.
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<h5 class="section-title" id="d7289247e438">Main Outcomes and Measures</h5>
<p id="d7289247e440">Sensitivity for Early Treatment of Retinopathy of Prematurity
type 1 ROP and potential
reduction in the number of infants requiring examinations. In the primary analysis,
the CHOP ROP model was applied weekly to predict the risk of ROP. If the risk was
above a cut-point level (high risk), examinations were indicated, while low-risk infants
received no examinations. In a secondary analysis, low-risk infants received fewer
examinations rather than no examinations.
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<h5 class="section-title" id="d7289247e443">Results</h5>
<p id="d7289247e445">Participants included 7483 premature infants at risk for ROP
with a known ROP outcome.
Their median BW was 1070 g (range, 310-3000 g), and their median GA was 28 weeks (range,
22-35 weeks). Among them, 3575 (47.8%) were female, and their race/ethnicity was 3615
white (48.3%), 2310 black (30.9%), 233 Asian (3.1%), 93 Pacific Islander (1.2%), and
40 American Indian/Alaskan native (0.5%). The original CHOP ROP model correctly predicted
452 of 459 infants who developed type 1 ROP (sensitivity, 98.5%; 95% CI, 96.9%-99.3%),
reducing the number of infants requiring examinations by 34.3% if only high-risk infants
received examinations. Lowering the cut point to capture all type 1 ROP cases (sensitivity,
100%; 95% CI, 99.2%-100%) resulted in only 6.8% of infants not requiring examinations.
However, if low-risk infants were examined at 37 weeks’ postmenstrual age and followed
up only if ROP was present at that examination, all type 1 ROP cases would be captured,
and the number of examinations performed among infants with GA exceeding 27 weeks
would be reduced by 28.4%.
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<h5 class="section-title" id="d7289247e448">Conclusion and Relevance</h5>
<p id="d7289247e450">The CHOP ROP model demonstrated high but not 100% sensitivity
and may be better used
to reduce examination frequency. The model might be used reliably to guide a modified
ROP screening schedule and decrease the number of examinations performed.
</p>
</div><p class="first" id="d7289247e453">This secondary analysis of data from the
Postnatal Growth and Retinopathy of Prematurity
Study seeks to validate the CHOP ROP model in a multicenter cohort large enough to
obtain a precise estimate of the model’s sensitivity for treatment-requiring retinopathy
of prematurity.
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