TY - JOUR
T1 - Development and validation of lupus nephritis case definitions using United States veterans affairs electronic health records
AU - Li, Tingting
AU - Lee, Iris
AU - Jayakumar, Divya
AU - Huang, Xinliang
AU - Xie, Yan
AU - Eisen, Seth
AU - Ranganathan, Prabha
N1 - Funding Information:
We would like to sincerely thank Margaret A. Olsen, PhD, MPH, Professor of Medicine and Director of Center for Administrative Data Research, Washington University in St. Louis, and Daniel Coyne, MD, Professor of Medicine, Washington University in St. Louis, for their expertise and guidance in study design and data analysis. The author(s) received no financial support for the research, authorship, and/or publication of this article.
Publisher Copyright:
© The Author(s) 2020.
PY - 2021/3
Y1 - 2021/3
N2 - Objective: International Classification of Diseases (ICD) codes are commonly used to identify patients with rare diseases in electronic health records (EHRs). However, misclassification is common, impacting the validity of study results. In this study, we compared the accuracies of several ICD-based case definitions of lupus nephritis (LN) in identifying United States veterans with LN. Methods: Using the Department of Veterans Affairs (VA) EHR, we identified all veterans with ≥1 ICD-9 or 10 diagnostic codes for systemic lupus erythematosus (SLE) between October 1, 1999 and September 30, 2017. A cohort was randomly selected for diagnostic validation and 9 ICD-based LN case definitions were applied to this cohort. The diagnostic accuracy of each definition was assessed against gold standard criterion of biopsy-proven LN. Results: 18,420 veterans had ≥1 ICD-9 or 10 diagnostic codes for SLE; 981 were randomly selected for diagnostic validation. 95 veterans (9.7%) had biopsy-proven LN. The case definitions had high specificity and NPV but variable sensitivity and PPV. The definition containing ≥2 ICD -9 codes for SLE and ≥2 nephritis indicators had the highest combination of sensitivity and specificity (87.4% and 94.6% respectively). ICD-10 code for LN had high specificity (99.8%) and PPV (93.9%). Conclusion: ICD-based case definitions of LN in the VA population have high specificity and NPV but variable sensitivity and PPV. Our results may help guide the design of future LN studies in VA cohorts. The choice of specific case definitions depends on the relative importance of different accuracy measures to individual studies.
AB - Objective: International Classification of Diseases (ICD) codes are commonly used to identify patients with rare diseases in electronic health records (EHRs). However, misclassification is common, impacting the validity of study results. In this study, we compared the accuracies of several ICD-based case definitions of lupus nephritis (LN) in identifying United States veterans with LN. Methods: Using the Department of Veterans Affairs (VA) EHR, we identified all veterans with ≥1 ICD-9 or 10 diagnostic codes for systemic lupus erythematosus (SLE) between October 1, 1999 and September 30, 2017. A cohort was randomly selected for diagnostic validation and 9 ICD-based LN case definitions were applied to this cohort. The diagnostic accuracy of each definition was assessed against gold standard criterion of biopsy-proven LN. Results: 18,420 veterans had ≥1 ICD-9 or 10 diagnostic codes for SLE; 981 were randomly selected for diagnostic validation. 95 veterans (9.7%) had biopsy-proven LN. The case definitions had high specificity and NPV but variable sensitivity and PPV. The definition containing ≥2 ICD -9 codes for SLE and ≥2 nephritis indicators had the highest combination of sensitivity and specificity (87.4% and 94.6% respectively). ICD-10 code for LN had high specificity (99.8%) and PPV (93.9%). Conclusion: ICD-based case definitions of LN in the VA population have high specificity and NPV but variable sensitivity and PPV. Our results may help guide the design of future LN studies in VA cohorts. The choice of specific case definitions depends on the relative importance of different accuracy measures to individual studies.
KW - International Classification of Diseases
KW - Lupus nephritis
KW - Veterans Affairs
KW - case definition
KW - electronic health records
KW - validation
UR - http://www.scopus.com/inward/record.url?scp=85095944483&partnerID=8YFLogxK
U2 - 10.1177/0961203320973267
DO - 10.1177/0961203320973267
M3 - Article
C2 - 33176569
AN - SCOPUS:85095944483
SN - 0961-2033
VL - 30
SP - 518
EP - 526
JO - Lupus
JF - Lupus
IS - 3
ER -