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Table 2 Diagnostic performance characteristics of three different algorithms for ICD-10 code N17x using the AKIN staging system for AKI as the reference standard

From: Validation of administrative database codes for acute kidney injury in kidney transplant recipients

Diagnostic coding algorithm AKIN stage Diagnostic performance characteristics (95 % CI)
All diagnoses AKIN stage 1 or greater Sn = 28.0 (22.6, 34.0)a
Sp = 97.2 (94.6, 98.6)
PPV = 89.2 (80.1, 94.4)
NPV = 62.2 (57.7, 66.6)
LR+ = 10.0
AKIN stage 2 or greater Sn = 42.1 (31.7, 53.3)
Sp = 90.6 (87.6, 93.0)
PPV = 43.2 (32.6, 54.6)
NPV = 90.2 (87.1, 92.6)
LR+ = 4.5
AKIN stage 3 Sn = 40.0 (28.1, 53.2)
Sp = 88.9 (85.8, 91.4)
PPV = 29.7 (20.5, 40.9)
NPV = 92.7 (89.9, 94.7)
LR+ = 3.6
Admission diagnosis AKIN stage 1 or greater Sn = 20.3 (15.7, 25.9)
Sp = 97.9 (95.5, 99.0)
PPV = 88.9 (77.8, 94.8)
NPV = 60.0 (55.5, 64.3)
LR+ = 9.7
AKIN stage 2 or greater Sn = 34.2 (24.5, 45.4)
Sp = 93.8 (91.1, 95.6)
PPV = 48.2 (35.4, 61.2)
NPV = 89.4 (86.3, 91.8)
LR+ = 5.5
AKIN stage 3 Sn = 32.7 (21.8, 45.9)
Sp = 92.3 (89.6, 94.4)
PPV = 33.3 (22.2, 46.6)
NPV = 92.1 (89.3, 94.2)
LR+ = 4.2
Main diagnosis/most responsible diagnosis AKIN stage 1 or greaterb  
AKIN stage 2 or greater Sn = 17.1 (10.3, 27.1)
Sp = 97.3 (95.4, 98.5)
PPV = 52.0 (33.5, 70.0)
NPV = 87.4 (84.2, 90.0)
LR+ = 6.3
AKIN stage 3 Sn = 18.2 (10.2, 30.3)
Sp = 96.8 (94.8, 98.1)
PPV = 40.0 (23.4, 59.3)
NPV = 91.0 (88.2, 93.2)
LR+ = 5.7
  1. aUsed the Wilson 95 % confidence interval
  2. bResults suppressed as per ICES privacy regulations due to the presence of small cells
  3. Sn sensitivity, Sp specificity, PPV positive predictive value, NPV negative predictive value, LR+ positive likelihood ratio