Accuracy of medical record scoring of the SLICC/ACR Damage Index for systemic lupus erythematosus

Abstract

Objective: To study the accuracy of medical record scoring of the SLICC/ACR Damage Index (DI) for SLE.

Methods: Medical record DI (MDI) scoring of 60 SLE patients by one physician was compared with prospective direct DI (DDI) scoring a median of 2 y earlier. Agreement between DDI and MDI total and organ system scores was compared using Cohen's kappa, the degree of misclassification by MDI and the significance of differences between DDI and MDI scores.

Results: The mean duration of SLE at DDI scoring was 5.2 y. The median/mean (SD) DDI and MDI total scores were 0=0.78 (1.38) and 0=0.85 (1.44). Damage was present on DDI and MDI scoring in 36.7% (22=60) and 38.3% (23=60) of patients. Qualitative MDI and DDI total scores (damage present/absent) showed good agreement (kappa ‘ 0.61, 95% CI ‘ 0.40–0.82, 18.3% misclassification). Quantitative MDI and DDI total scores (degree of damage) showed moderate agreement (kappa ‘ 0.47, 95% CI ‘ 0.28–0.66, 36.7% misclassification). 9 of 12 MDI organ system scores misclassified < 10% of subjects. There was no statistically significant difference between DDI and MDI total or organ system scores.

Conclusion: MDI total scoring is a good qualitative and moderate quantitative reflection of SLE related damage. MDI organ system scores are more accurate than MDI total scores.