Table 3

Performance of ICD-10 code algorithms for LN

Number of codesPPV (%)Sensitivity (%)Specificity (%)F1 score (%)LR
LN codes without separation19979998879
21005810074
31004910066
41003710054
LN codes separated by 30 days1997910088
21004910073
31003710066
4100010054
SLE and proteinuria/nephritis codes19316992712
2No patients had two codes.
31000100
SLE and proteinuria/nephritis codes separated by 30 days115992711
2100910025
3100410016
410001009
  • ∞, Infinity; F1 score, harmonic mean of precision and recall scores; ICD-10, International Classification of Diseases, 10th Revision; LN, lupus nephritis; LR, likelihood ratio; PPV, positive predictive value.