Economic evaluation of damage accrual in an international SLE inception cohort using a multi-state model approach

OBJECTIVES: There is a paucity of data regarding healthcare costs associated with damage accrual in systemic lupus erythematosus (SLE). We describe costs associated with damage states across the disease course using multi-state modeling. METHODS: Patients from 33 centres in 11 countries were enrolled in the Systemic Lupus International Collaborating Clinics (SLICC) inception cohort within 15 months of diagnosis. Annual data on demographics, disease activity, damage (SLICC/American College of Rheumatology (ACR) Damage Index [SDI]), hospitalizations, medications, dialysis, and selected procedures were collected. Ten-year cumulative costs (Canadian dollars) were estimated by multiplying annual costs associated with each SDI state by the expected state duration using a multi-state model. RESULTS: 1687 patients participated, 88.7% female, 49.0% of Caucasian race/ethnicity, mean age at diagnosis 34.6 years (SD 13.3), and mean follow up 8.9 years (range 0.6-18.5). Annual costs were higher in those with higher SDIs (SDI ≥ 5: $22 006 2019 CDN, 95$16 662, $27 350 versus SDI=0:$1833, 95% CI $1134,$2532). Similarly, 10-year cumulative costs were higher in those with higher SDIs at the beginning of the 10-year interval (SDI ≥ 5: $189 073, 95$142 318, $235 827 versus SDI=0:$21 713, 95% CI $13 639,$29 788). CONCLUSION: Patients with the highest SDIs incur 10-year cumulative costs that are almost 9-fold higher than those with the lowest SDIs. By estimating the damage trajectory and incorporating annual costs, damage can be used to estimate future costs, critical knowledge for evaluating the cost-effectiveness of novel therapies

Economic Evaluation of Lupus Nephritis in the Systemic Lupus International Collaborating Clinics Inception Cohort Using a Multistate Model Approach

OBJECTIVE: Little is known about the long-term costs of lupus nephritis (LN). These were compared between patients with and without LN based on multistate modelling. METHODS: Patients from 32 centres in 11 countries were enrolled in the Systemic Lupus International Collaborating Clinics (SLICC) inception cohort within 15 months of diagnosis and provided annual data on renal function, hospitalizations, medications, dialysis, and selected procedures. LN was diagnosed by renal biopsy or the American College of Rheumatology classification criteria. Renal function was assessed annually using estimated glomerular filtration rate (eGFR) or proteinuria (ePrU). A multistate model was used to predict 10-year cumulative costs by multiplying annual costs associated with each renal state by the expected state duration. RESULTS: 1,545 patients participated, 89.3% female, mean age at diagnosis 35.2 years (SD 13.4), 49.0% Caucasian, and mean follow up 6.3 years (SD 3.3). LN developed in 39.4% by the end of follow up. Ten-year cumulative costs were greater in those with LN and an eGFR 60 ml/min) or with LN and ePrU > 3 g/d ($84 040 versus$20 499 if no LN and ePrU < 0.25 g/d). CONCLUSION: Patients with eGFR < 30 ml/min incurred 10-year costs 15-fold higher than those with normal eGFR. By estimating the expected duration in each renal state and incorporating associated annual costs, disease severity at presentation can be used to anticipate future healthcare costs. This is critical knowledge for cost-effectiveness evaluations of novel therapies

Evaluating the construct of damage in systemic lupus erythematosus

OBJECTIVE: The Systemic Lupus International Collaborating Clinics, American College of Rheumatology and Lupus Foundation of America are developing a revised SLE Damage Index (SDI). Shifts in the concept of damage in SLE have occurred with new insights into disease manifestations, diagnostics, and therapy. We evaluated contemporary constructs in SLE damage to inform development of the revised SDI. METHODS: We conducted a 3-part qualitative study of international SLE experts. Facilitated small groups evaluated the construct underlying the concept of damage in SLE. A consensus meeting using nominal group technique was conducted to achieve agreement on aspects of the conceptual framework and scope of the revised damage index. The framework was finally reviewed and agreed upon by the entire group. RESULTS: Fifty participants from 13 countries were included. Eight thematic clusters underlying the construct of SLE damage were purpose, items, weighting, reversibility, impact, timeframe, attribution, and perspective. The revised SDI will be a discriminative index to measure morbidity in SLE, independent of activity or impact on the patient, and should be related to mortality. The SDI is primarily intended for research purposes and should take a life course approach. Damage can occur before a diagnosis of SLE but should be attributable to SLE. Damage to an organ is irreversible but the functional consequences on that organ may improve over time through physiological adaptation or treatment. CONCLUSION: We identified shifts in the paradigm of SLE damage and developed a unifying conceptual framework. These data form the groundwork for the next phases of SDI development