Table 4.

Diagnostic accuracy of International Classification of Diseases, Tenth Revision codes for advanced chronic kidney disease (CKD) compared to estimated glomerular filtration rate (eGFR)-based defining criteria.

Accuracy metric	Index eGFRa <30 (n=1371), point estimate (95% CI)b	Index eGFR <30 and 90 days prior eGFR <60 (n=1346), point estimate (95% CI)	High-risk advanced CKD (n=928), point estimate (95% CI)	High- and intermediate-risk advanced CKD (n=1408), point estimate (95% CI)
Sensitivity	0.55 (0.52-0.57)	0.55 (0.53-0.58)	0.65 (0.62-0.68)	0.57 (0.55-0.60)
Specificity	1.00 (1.00-1.00)	1.00 (1.00-1.00)	0.99 (0.99-1.00)	1.00 (1.00-1.00)
Positive predictive value	0.68 (0.66-0.71)	0.68 (0.65-0.71)	0.55 (0.52-0.58)	0.74 (0.71-0.76)
Negative predictive value	0.99 (0.99-0.99)	0.99 (0.99-0.99)	1.00 (1.00-1.00)	0.99 (0.99-0.99)

^aIndex eGFR refers to the latest eGFR measure (ml·min^–1·m^–2) at the time of extraction of the cohort.

^b20 patients were excluded from this column because they were missing a prior eGFR value; the subsequent column criteria/definitions required two eGFR values, and thus patients without two eGFR values were excluded for consistency between column criteria/definitions.