Remission and low disease activity are associated with lower healthcare costs: results from the Systemic Lupus International Collaborating Clinics (SLICC) inception cohort.

OBJECTIVES: This study aims to determine the independent impact of definitions of remission/low disease activity (LDA) on direct/indirect costs (DCs, ICs) in a multicentre inception cohort. METHODS: Patients from 31 centres in 10 countries were enrolled within 15 months of diagnosis and assessed annually. Five mutually exclusive disease activity states (DAS) were defined as (1) remission off-treatment: clinical (c) SLEDAI-2K=0, without prednisone/immunosuppressants; (2) remission on-treatment: cSLEDAI-2K=0, prednisone ≤5 mg/day and/or maintenance immunosuppressants; (3) LDA-Toronto Cohort (TC): cSLEDAI-2K≤2, without prednisone/immunosuppressants; (4) modified lupus LDA state (mLLDAS): SLEDAI-2K≤4, no activity in major organs/systems, no new activity, prednisone ≤7.5 mg/day and/or maintenance immunosuppressants and (5) active: all remaining assessments.At each assessment, patients were stratified into the most stringent DAS fulfilled and the proportion of time in a DAS since cohort entry was determined. Annual DCs/ICs (2021 Canadian dollars) were based on healthcare use and lost workforce/non-workforce productivity over the preceding year.The association between the proportion of time in a DAS and annual DC/IC was examined through multivariable random-effects linear regressions. RESULTS: 1692 patients were followed a mean of 9.7 years; 49.0% of assessments were active. Remission/LDA (per 25% increase in time in a remission/LDA state vs active) were associated with lower annual DC/IC: remission off-treatment (DC -$C1372; IC -$C2507), remission on-treatment (DC -$C973; IC -$C2604,) LDA-TC (DC -$C1158) and mLLDAS (DC -$C1040). There were no cost differences between remission/LDA states. CONCLUSIONS: Our data suggest that systemic lupus erythematosus patients who achieve remission, both off and on-therapy, and reductions in disease activity incur lower costs than those experiencing persistent disease activity.

Assessing the Costs of Neuropsychiatric Disease in the Systemic Lupus International Collaborating Clinics Cohort Using Multistate Modeling.

OBJECTIVE: To estimate direct and indirect costs associated with neuropsychiatric (NP) events in the Systemic Lupus International Collaborating Clinics inception cohort. METHODS: NP events were documented annually using American College of Rheumatology definitions for NP events and attributed to systemic lupus erythematosus (SLE) or non-SLE causes. Patients were stratified into 1 of 3 NP states (no, resolved, or new/ongoing NP event). Change in NP status was characterized by interstate transition rates using multistate modeling. Annual direct costs and indirect costs were based on health care use and impaired productivity over the preceding year. Annual costs associated with NP states and NP events were calculated by averaging all observations in each state and adjusted through random-effects regressions. Five- and 10-year costs for NP states were predicted by multiplying adjusted annual costs per state by expected state duration, forecasted using multistate modeling. RESULTS: A total of 1,697 patients (49% White race/ethnicity) were followed for a mean of 9.6 years. NP events (n = 1,971) occurred in 956 patients, 32% attributed to SLE. For SLE and non-SLE NP events, predicted annual, 5-, and 10-year direct costs and indirect costs were higher in new/ongoing versus no events. Direct costs were 1.5-fold higher and indirect costs 1.3-fold higher in new/ongoing versus no events. Indirect costs exceeded direct costs 3.0 to 5.2 fold. Among frequent SLE NP events, new/ongoing seizure disorder and cerebrovascular disease accounted for the largest increases in annual direct costs. For non-SLE NP events, new/ongoing polyneuropathy accounted for the largest increase in annual direct costs, and new/ongoing headache and mood disorder for the largest increases in indirect costs. CONCLUSION: Patients with new/ongoing SLE or non-SLE NP events incurred higher direct and indirect costs.

Economic Evaluation of Damage Accrual in an International Systemic Lupus Erythematosus Inception Cohort Using a Multistate Model Approach.

OBJECTIVE: There is a paucity of data regarding health care costs associated with damage accrual in systemic lupus erythematosus. The present study was undertaken to describe costs associated with damage states across the disease course using multistate modeling. METHODS: Patients from 33 centers 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 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 multistate model. RESULTS: A total of 1,687 patients participated; 88.7% were female, 49.0% were white, mean ± SD age at diagnosis was 34.6 ± 13.3 years, and mean time to follow-up was 8.9 years (range 0.6-18.5 years). Mean annual costs were higher for those with higher SDI scores as follows: $22,006 (Canadian) (95% confidence interval [95% CI] $16,662, $27,350) for SDI scores ≥5 versus $1,833 (95% CI $1,134, $2,532) for SDI scores of 0. Similarly, 10-year cumulative costs were higher for those with higher SDI scores at the beginning of the 10-year interval as follows: $189,073 (Canadian) (95% CI $142,318, $235,827) for SDI scores ≥5 versus $21,713 (95% CI $13,639, $29,788) for SDI scores of 0. CONCLUSION: Patients with the highest SDI scores incur 10-year cumulative costs that are ~9-fold higher than those with the lowest SDI scores. By estimating the damage trajectory and incorporating annual costs, data on damage can be used to estimate future costs, which is 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). The costs were compared between patients with and without LN using multistate modeling. METHODS: Patients from 32 centers in 11 countries were enrolled in the Systemic Lupus International Collaborating Clinics 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 the estimated glomerular filtration rate (GFR) or estimated proteinuria. 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: A total of 1,545 patients participated; 89.3% were women, the mean ± age at diagnosis was 35.2 ± 13.4 years, 49% were white, and the mean followup duration was 6.3 ± 3.3 years. LN developed in 39.4% of these patients by the end of followup. Ten-year cumulative costs were greater in those with LN and an estimated glomerular filtration rate (GFR) <30 ml/minute ($310,579 2015 Canadian dollars versus $19,987 if no LN and estimated GFR >60 ml/minute) or with LN and estimated proteinuria >3 gm/day ($84,040 versus $20,499 if no LN and estimated proteinuria <0.25 gm/day). CONCLUSION: Patients with estimated GFR <30 ml/minute incurred 10-year costs 15-fold higher than those with normal estimated GFR. By estimating the expected duration in each renal state and incorporating associated annual costs, disease severity at presentation can be used to anticipate future health care costs. This is critical knowledge for cost-effectiveness evaluations of novel therapies.

American College of Rheumatology criteria at inception, and accrual over 5 years in the SLICC inception cohort.

OBJECTIVE: To determine the frequency of each American College of Rheumatology (ACR) criterion met at time of enrollment, and the increase in each of the criteria over 5 years. METHODS: In 2000 the Systemic Lupus International Collaborating Clinics (SLICC) recruited an international inception cohort of patients with systemic lupus erythematosus (SLE; ≥ 4 ACR criteria) who were followed at yearly intervals according to a standard protocol. Descriptive statistics were used to assess the total and cumulative number of ACR criteria met at each visit. Regression models were done to compare the increase of individual and cumulative criteria as a function of race/ethnicity group, and sex. RESULTS: In all, 768 patients have been followed for a minimum of 5 years. Overall, 59.1% of the patients had an increase in the number of ACR criteria they met over the 5-year period. The mean number of ACR criteria met at enrollment was 5.04 ± 1.13 and at year 5 was 6.03 ± 1.42. At enrollment, nonwhite patients had a higher number of ACR criteria (5.19 ± 1.23) than white patients. The total number of criteria increased in both white and nonwhite ethnicities, but increased more among whites. Males had a slightly lower number of criteria at enrollment compared to females and males accrued fewer criteria at 5 years. CONCLUSION: In this international inception cohort of SLE patients with at least 4 ACR criteria at entry, there was an accumulation of ACR criteria over the following 5 years. The distribution of criteria both at inception and over 5 years is affected by sex and ethnicity.

Efficacy and safety of rituximab in patients with active proliferative lupus nephritis: the Lupus Nephritis Assessment with Rituximab study.

OBJECTIVE: To evaluate the efficacy and safety of rituximab in a randomized, double-blind, placebo-controlled phase III trial in patients with lupus nephritis treated concomitantly with mycophenolate mofetil (MMF) and corticosteroids. METHODS: Patients (n = 144) with class III or class IV lupus nephritis were randomized 1:1 to receive rituximab (1,000 mg) or placebo on days 1, 15, 168, and 182. The primary end point was renal response status at week 52. RESULTS: Rituximab depleted peripheral CD19+ B cells in 71 of 72 patients. The overall (complete and partial) renal response rates were 45.8% among the 72 patients receiving placebo and 56.9% among the 72 patients receiving rituximab (P = 0.18); partial responses accounted for most of the difference. The primary end point (superior response rate with rituximab) was not achieved. Eight placebo-treated patients and no rituximab-treated patients required cyclophosphamide rescue therapy through week 52. Statistically significant improvements in serum complement C3, C4, and anti-double-stranded DNA (anti-dsDNA) levels were observed among patients treated with rituximab. In both treatment groups, a reduction in anti-dsDNA levels greater than the median reduction was associated with reduced proteinuria. The rates of serious adverse events, including infections, were similar in both groups. Neutropenia, leukopenia, and hypotension occurred more frequently in the rituximab group. CONCLUSION: Although rituximab therapy led to more responders and greater reductions in anti-dsDNA and C3/C4 levels, it did not improve clinical outcomes after 1 year of treatment. The combination of rituximab with MMF and corticosteroids did not result in any new or unexpected safety signals.