Table 2.

Identification of Chronic Kidney Disease. First, second and fourth rows: Percent of study population at each institution identified with CKD based on laboratory results alone, laboratory results plus documented ICD-10 or HCC diagnosis code, and documented ICD-10 or HCC diagnosis code and no laboratory results, respectively. Absolute numbers of patients in each category are shown in the parentheses as the numerator; total number of patients with CKD by either-or-both laboratory and/or diagnosis code are given as the denominator. Third row: Percent of the subset patients at each institution who had in-system laboratory evidence of CKD and had a diagnosis code for CKD; absolute numbers are shown in the parentheses as numerator (from second row), total number of patients with evidence of CKD on the basis of in-system laboratory data are shown as the denominator (sum of first and second rows).

	Institution A	Institution B	Institution C
In-system Lab Results Only	78% (12,478/16,063)	32% (487/1511)	66% (19,433/29,277)
In-system Lab plus Diagnosis Code	4% (645/16,063)	19% (282/1511)	22% (6,582/29,277)
Diagnosis code for in-system Lab Results	5%  (645/13,123)	37% (282/769)	25% (6,582/26,015)
Diagnosis Code Only	18% (2,940/16,063)	49% (742/1511)	11% (3,262/29,277)