Table 5.

Subgroup analyses of sensitivity and specificity of RW-ROP^* from Trained Readers Grading – Single Session Per Eye Analysis^**

	# of eyes RW-ROP present from diagnostic examination	# of eyes RW-ROP positive from image grading	Sensitivity (95% CI)	# of eyes RW-ROP absent from diagnostic examination	# of eyes RW-ROP negative from image grading	Specificity (95% CI)
Birth weight
≤750 g (n=655)	317	264	83.3% (77.9–87.6%)	338	274	81.1% (75.7–85.5%)
>750, ≤900 g (n=353)	74	62	83.8% (73.3–90.7%)	279	243	87.1% (81.7–91.1%)
>900 g (n=697)	56	40	71.4% (55.5–83.4%)	641	616	96.1% (94.0–97.5%)
Gestation age
≤ 24 weeks (n=186)	128	106	82.8% (73.0–89.6%)	58	47	81.0% (67.9–89.6%)
>24, ≤ 26 weeks (n=528)	214	183	85.5% (79.9–89.8%)	314	253	80.6% (74.9–85.2%)
>26 weeks (n=991)	105	77	73.3% (62.1, 82.2%)	886	833	94.0% (91.9–95.6%)
Good/adequate quality in all 5 retinal images
No (n=400)	75	51	68.0% (56.0–78.0%)	325	288	88.6% (84.2–91.9%)
Yes (n=1305)	372	315	84.7% (80.0–88.4%)	933	845	90.6% (88.2–92.5%)

95% CI = 95% confidence interval

^*RW-ROP = referral warranted retinopathy of prematurity defined as the presence of zone I ROP, stage 3 ROP or plus disease.

^**For infants with RW-ROP, the images from the session when diagnostic examination first identified findings consistent with RW-ROP were used. For infants without RW-ROP, a random image session was selected.