ABSTRACT
OBJECTIVE: The SLEDAI 2000 (SLEDAI-2K) Responder Index 50 (SRI-50) is a novel index that measures ≥ 50% in each of the 24 descriptors of SLEDAI-2K and generates a total score reflecting disease activity overall. The SLE Responder Index (SRI) has been successfully used to identify responders in recent trials. This is the first study to evaluate the ability of SRI-50 to identify responders, defined as patients who had a clinically important improvement over their baseline value over 12 months. We compared the performance of SRI-50 with that of SLEDAI-2K and SRI at 6 and 12 months in identifying responders. METHODS: Patients with active disease were followed for 6-12 months and assessed using SLEDAI-2K, British Isles Lupus Assessment Group and Physician Global Assessment. We identified SLEDAI-2K responders, SRI-50 responders and SLE responders at 6 and 12 months. We determined whether patients who are defined as SRI-50 responders are true responders when SRI is considered the gold standard. RESULTS: Among the 103 patients studied, the percentage of responders at 6 and 12 months was 44 and 51% when determined by SLEDAI-2K and 43 and 51% by SRI, respectively. The percentage of SRI-50 responders at 6 and 12 months was 51 and 58%, respectively. CONCLUSION: SRI-50 identified more responders compared with SLEDAI-2K and SRI at 6 and 12 months. SRI-50 is a valid responder index that can be used independently to identify patients with true clinically important improvement.
Subject(s)
Lupus Erythematosus, Systemic/diagnosis , Adult , Female , Follow-Up Studies , Glucocorticoids/therapeutic use , Humans , Lupus Erythematosus, Systemic/drug therapy , Lupus Erythematosus, Systemic/physiopathology , Male , Middle Aged , Prednisone/therapeutic use , Severity of Illness Index , Treatment OutcomeABSTRACT
OBJECTIVE: To evaluate the performance of the Systemic Lupus Erythematosus (SLE) Responder Index (SRI) when the SLE Disease Activity Index 2000 (SLEDAI-2K) is substituted with SLEDAI-2K Responder Index-50 (SRI-50), a valid and reliable index of disease activity improvement. Also, to determine whether the SRI-50 will enhance the ability of SRI in detecting responders. METHODS: Our study was conducted on patients who attended the Lupus Clinic from September 2009 to September 2010. SLEDAI-2K, SRI-50, the British Isles Lupus Assessment Group measure, and the Physician's Global Assessment were determined initially and at followup. SRI was determined at the followup visit according to its original definition using the SLEDAI-2K score and by substituting SLEDAI-2K with SRI-50. RESULTS: A total of 117 patients with SLEDAI-2K ≥ 4 at baseline were studied. Patients had 1 followup visit over a 3-month period. Twenty-nine percent of patients met the original definition of SRI and 35% of patients met the definition of SRI when SLEDAI-2K was substituted with SRI-50. The use of SRI-50 allowed determination of significant improvement in 7 additional patients. This improvement could not be discerned with the use of SLEDAI-2K as a component of SRI. At followup visits that showed improvement, SRI-50 scores decreased to a greater extent than SLEDAI-2K scores (p < 0.0001). CONCLUSION: SRI-50 enhances the ability of SRI to identify patients with clinically important improvement in disease activity. SRI-50 was superior to SLEDAI-2K in detecting partial clinical improvement, ≥ 50%, between visits. These properties of the SRI-50 enable it to be used as an independent outcome measure of improvement or as a component of SRI in clinical trials.
Subject(s)
Disability Evaluation , Immunosuppressive Agents/therapeutic use , Lupus Erythematosus, Systemic/drug therapy , Outcome Assessment, Health Care/methods , Severity of Illness Index , Adult , Antibodies, Monoclonal/therapeutic use , Antibodies, Monoclonal, Humanized , Female , Follow-Up Studies , Humans , Longitudinal Studies , Lupus Erythematosus, Systemic/diagnosis , Male , Middle Aged , Prospective Studies , Reproducibility of Results , Retrospective Studies , Treatment Outcome , United KingdomABSTRACT
OBJECTIVE: To test the interrater and intrarater reliability of the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) Responder Index (SRI-50), an index designed to measure ≥ 50% improvement in disease activity between visits in patients with systemic lupus erythematosus. METHODS: This was a multicenter, cross-sectional study with raters from Canada, the United Kingdom, and Argentina. Patient profile scenarios were derived from real adult patients. Ten rheumatologists from university and community hospitals and postdoctoral rheumatology fellows participated. An SRI-50 data retrieval form was used. Each rheumatologist scored SLEDAI-2K at the baseline visit and SRI-50 on followup visit, for the same patients, on 2 occasions 2 weeks apart. Physician global assessment (PGA) was determined on a numerical scale at baseline visit and a Likert scale on followup visit. Interrater and intrarater reliability was assessed using intraclass correlation coefficient (ICC) and kappa statistics whenever applicable. RESULTS: Forty patient profiles were created. The ICC performed on 80 patient profiles for interrater ranged from 1.00 for SLEDAI-2K and SRI-50 to 0.96 for PGA. The intrarater ICC for SLEDAI-2K, SRI-50, and PGA scores ranged from 1.00 to 0.86. Substantial agreement was determined for the interrater Likert scale, with a kappa statistic of 0.57. CONCLUSION: The SRI-50 is reliable to assess ≥ 50% improvement in lupus disease activity. Use of the SRI-50 data retrieval form is essential to ensure optimal performance of the SRI-50. SRI-50 can be used by both rheumatologists and trainees and performs equally well in trained as well as untrained rheumatologists.
