TABLE 2.

Positive predictive values comparing algorithms of ICD-9 and ICD-10 claims-based diagnoses of CKD Stages 3–5 to eGFR based on laboratory values

Algorithm	ICD-9 period 2012–2014	ICD-10 period 2016–2018
1 CKD diagnosis, lab ± 90 days	N = 146 739	N = 380 117
PPV (%), 95% CI
Comparison to eGFR (CKD-EPI)	81.24 (81.04, 81.44)	82.00 (81.87, 82.12)
Comparison to eGFR (MDRD)	81.89 (81.70, 82.09)	82.03 (81.91, 82.15)
2 CKD diagnoses, lab ± 90 days	N = 104 774	N = 285 520
PPV (%), 95% CI
Comparison to eGFR (CKD-EPI)	86.36 (86.15, 86.57)	86.07 (85.94, 86.20)
Comparison to eGFR (MDRD)	86.67 (86.47, 86.88)	85.93 (85.80, 86.06)
1 CKD diagnosis, lab ± 180 days	N = 155 730	N = 386 331
PPV (%), 95% CI
Comparison to eGFR (CKD-EPI)	80.32 (80.12, 80.52)	81.56 (81.43, 81.68)
Comparison to eGFR (MDRD)	80.91 (80.71, 81.10)	81.46 (81.34, 81.59)
2 CKD diagnoses, lab ± 180 days	N = 110 540	N = 286 745
PPV (%), 95% CI
Comparison to eGFR (CKD-EPI)	85.30 (85.09, 85.51)	85.56 (85.43, 85.69)
Comparison to eGFR (MDRD)	85.60 (85.40, 85.81)	85.30 (85.17, 85.43)
1 CKD diagnosis, lab ± 365 days	N = 161 305	N = 373 220
PPV (%), 95% CI
Comparison to eGFR (CKD-EPI)	78.80 (78.61, 79.00)	80.63 (80.50, 80.76)
Comparison to eGFR (MDRD)	79.21 (79.01, 79.41)	80.40 (80.27, 80.52)
2 CKD diagnoses, lab ± 365 days	N = 111 329	N = 270 553
PPV (%), 95% CI
Comparison to eGFR (CKD-EPI)	84.06 (83.84, 84.27)	84.81 (84.67, 84.94)
Comparison to eGFR (MDRD)	84.12 (83.91, 84.34)	84.41 (84.27, 84.54)

Note: Lab assessment window is described by the X-days lab label. For example, the 90-days lab label describes an analysis in which patients had a creatinine laboratory value 90 days before or after their claims-based CKD diagnosis.

Abbreviations: CKD-EPI, chronic kidney disease epidemiology collaboration; MDRD, the modification of diet in renal disease.