Table 2

Diagnostic performance of lupus nephritis (LN) International Classification of Diseases (ICD) codes

Test setDiagnostic criteriaLN definitionSensitivity, %Specificity, %PPV,
%
NPV,
%
Accuracy, %
UCSF≥1 ICD codeStrict5694838181
Inclusive5197917478
≥2 ICD codes, ≥30 days apartStrict5096857980
Inclusive4395857174
ZSFG
(external set)
≥1 ICD codeStrict7392858384
Inclusive6593887680
≥2 ICD codes, ≥30 days apartStrict5595887679
Inclusive5096926975
  • Performance of LN diagnosis codes for identifying prevalent cases of LN.

  • Inclusive, definite LN, potential LN or diagnostic uncertainty; NPV, negative predictive value; PPV, positive predictive value; Strict, definite LN only; UCSF, University of California San Francisco; ZSFG, Zuckerberg San Francisco General.