Quantitative analysis of apparent diffusion coefficients to predict neurological prognosis in cardiac arrest survivors: an observational derivation and internal–external validation study

Table 4 Comparison of prognostic performance of ADC - R(650) cutoff of > 10% and > 20.5% in derivation, internal validation, and external validation cohorts

Cohorts	Cut-off value, ADC - R(650)^a	FP	FN	TP	TN	Sensitivity (95% CI)	Specificity (95% CI)	PPV (95% CI)	NPV (95% CI)
Derivation	> 10%	53	11	127	33	92.0 (86.2─96.0)	39.5 (29.2─50.7)	70.9 (67.2─74.5)	75.6 (62.3─85.2)
Derivation	> 20.5%	0	33	107	85	76.8 (68.9─83.6)	100 (95.8─100.0)	100	72.9 (66.5─78.5)
Internal validation	> 10%	16	5	63	12	92.7 (83.7─97.6)	46.4 (27.5─66.1)	80.8 (74.7─85.6)	72.2 (50.6─86.9)
Internal validation	> 20.5%	0	19	49	28	66.2 (53.4─77.4)	100 (88.8─100.0)	100	58.5 (50.1─66.4)
External validation	> 10%	44	4	59	21	93.7 (84.5─98.2)	33.9 (22.6─46.6)	57.8 (53.5─62.3)	84.6 (66.8─93.8)
External validation	> 20.5%	1	12	51	64	79.4 (67.3─88.5)	98.5 (91.7─100.0)	98.0 (97.7─99.7)	83.1 (75.2─88.9)

^aThe definition of ADC - R(650) is the ratio of voxels with ADC values ranging from 200 × 10⁻⁶ mm²/s to the 650 × 10⁻⁶ mm²/s
FP number of patients with a false-positive test result, FN Number of patients with a false-negative test result, TP Number of patients with a true positive test result, TN number of patients with a true negative test result, CI Confidence interval, PPV Positive predictive value, NPV Negative predictive value

ISSN: 1364-8535