Objective: To evaluate the comparability of prospective and retrospective evaluations of the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SLICC/ACR DI).
Methods: Consecutive patients meeting ACR criteria for SLE were enrolled prospectively in our cohort. Prospective SLICC/ACR DI scores were collected on the 134 cohort members who were observed in the cohort between 1993-1999. The last available prospective SLICC/ACR DI scores were compared to scores that were retrospectively assigned (for the corresponding time point) from chart review by a research nurse blinded to the prospective values. Intra- and inter-observer agreement was assessed. Kappa coefficients with 95% confidence intervals (CI) were determined.
Results: The kappa correlation coefficient for agreement between prospective versus retrospective total damage scores was 0.68 (95% CI 0.54-0.81). Moderate to very good agreement was also observed with respect to the 12 individual organ systems itemized in this damage index. Substantial agreement was found between assessments done by different research nurses and for repeat assessments done by the same research nurse.
Conclusion: These data suggest good agreement between prospective and retrospective evaluations of the SLICC/ACR DI scores.