Table 1.

Performance characteristics of ultrasonographic diagnostic criteria for type 1 and 2 ADPKD in at-risk individuals between 15 and 29 yr of age^a

Diagnostic Criterion	Disease Subtype	Sensitivity	Specificity	NPV	PPV	Accuracy
≥1 renal cyst	PKD1	0.991 (0.969 to 1.000)	0.976 (0.945 to 1.000)	0.991 (0.970 to 1.000)	0.975 (0.940 to 1.000)	0.983 (0.964 to 1.000)
	PKD2	0.791 (0.674 to 0.896)	0.966 (0.911 to 1.000)	0.835 (0.743 to 0.917)	0.956 (0.880 to 1.000)	0.883 (0.817 to 0.938)
≥2 renal cystsb	PKD1	0.981 (0.951 to 1.000)	0.988 (0.963 to 1.000)	0.983 (0.951 to 1.000)	0.987 (0.961 to 1.000)	0.985 (0.967 to 1.000)
	PKD2	0.719 (0.593 to 0.830)	1.000	0.797 (0.697 to 0.880)	1.000	0.866 (0.798 to 0.922)
≥3 renal cystsb	PKD1	0.943 (0.891 to 0.981)	1.000	0.948 (0.901 to 0.983)	1.000	0.971 (0.946 to 0.991)
	PKD2	0.695 (0.567 to 0.812)	1.000	0.780 (0.681 to 0.866)	1.000	0.854 (0.784 to 0.915)

^aData are means (95% confidence interval [CI]). Accuracy of each test criterion was derived from 1000 bootstrap samples of the original data. NPV, negative predictive value; PPV, positive predictive value.

^bUnilateral or bilateral.