Session Information
Date: Sunday, November 8, 2015
Title: Systemic Lupus Erythematosus - Clinical Aspects and Treatment I: Epidemiology and Prognosis
Session Type: ACR Concurrent Abstract Session
Session Time: 2:30PM-4:00PM
Background/Purpose:
Little is known about the long-term costs of lupus nephritis (LN). The annual and long-term healthcare costs were compared between SLE patients with and without LN.
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, dialysis, and utilization of medications and selected procedures. LN was diagnosed by renal biopsy or fulfillment of the American College of Rheumatology (ACR) SLE classification criteria renal item. Renal function was also assessed annually based on estimated glomerular filtration rate (eGFR) or proteinuria (ePrU). Annual health resource utilization was costed using 2012 Canadian prices. Annual costs associated with renal function states were obtained from multiple regressions adjusting for age, race/ethnicity, disease duration, SLICC centre location, SLEDAI-2K and SLICC/ACR Damage Index (excluding renal components), and the SF-36. 5-year cumulative costs were estimated by determining annual costs associated with each renal function state and then forecasting the expected duration in each state. Durations were estimated using a relative risk regression model.
Results:
1645 patients participated, 89.2% females, 48.8% Caucasian, mean age at diagnosis 34.8 years (SD 13.4), mean disease duration at enrollment 0.5 years (SD 0.3), and mean follow up 6.1 years (SD 3.3). LN was diagnosed in 39.4% over follow up. Health resource utilization and annual costs (after adjustment using regression) were markedly higher in those with an eGFR < 30 ml/min or with LN (Table 1).
|
Table 1. Predicted Annual Health Costs Stratified by State of Renal Function |
|||||
|
eGFR |
ePrU |
Lupus Nephritis |
|||
|
State |
Costs, Mean 95% CI 2012 CDN$ |
State |
Costs, Mean 95% CI 2012 CDN$ |
State |
Costs, Mean 95% CI 2012 CDN$ |
|
eGFR >60 ml/min
|
2234 (1503, 2965) |
ePrU< 0.25g/d
|
2247 (1406, 3088) |
No Lupus Nephritis |
1588 (726,2450) |
|
eGFR 30-60ml/min
|
3014 (1636, 4392) |
ePrU 0.25-3.0g/d
|
3424 (2287, 4561) |
Lupus Nephritis |
3876 (2949,4803) |
|
eGFR < 30 ml/min
|
12551 (10301, 14801) |
ePrU > 3.0 g/d
|
4703 (2128, 7278) |
|
|
5-year cumulative costs stratified by baseline renal function state were calculated by multiplying the annual costs associated with each state by the expected duration in that state (eGFR example in Table 2).
|
Table 2. Expected Duration in Each Renal State over 5 Years |
||||
|
|
Expected Duration in each State over 5 years |
|||
|
Baseline State |
Annual Costs 2012 CDN$ |
eGFR >60 ml/ min |
eGFR 30-60 ml/min |
eGFR < 30 ml/min |
|
eGFR >60 ml/ min |
2234 |
4.74 yrs |
0.22 yrs |
0.04 yrs |
|
eGFR 30-60 ml/min |
3014 |
2.60 yrs |
1.88 yrs |
0.52 yrs |
|
eGFR < 30 ml/min |
12551 |
1.03 yrs |
1.09 yrs |
2.88 yrs |
Five year cumulative costs were greater in those with severely impaired eGFR or with LN at baseline (Table 3).
|
Table 3. Predicted 5-Year Cumulative Health Costs Stratified by Baseline State of Renal Function |
|||||
|
eGFR |
ePrU |
Lupus Nephritis |
|||
|
Baseline State |
Costs, Mean 95% CI 2012 CDN$ |
Baseline State |
Costs, Mean 95% CI 2012 CDN$ |
Baseline State |
Costs, Mean 95% CI 2012 CDN$ |
|
eGFR >60 ml/ min
|
11763 (7904, 15622) |
ePrU< 0.25 g/d
|
12070 (7594, 16547) |
No Lupus Nephritis |
8663 (4331, 12995) |
|
eGFR 30-60 ml/min
|
18008 (12348, 23667) |
ePrU 0.25-3.0 g/d
|
13834 (8758, 18909) |
Lupus Nephritis |
19380 (14745, 24015) |
|
eGFR < 30 ml/min
|
41732 (32998, 50467) |
ePrU > 3.0 g/d
|
15627 (9192, 22061) |
|
|
|
|
|||||
Conclusion:
Patients with an eGFR <30ml/min and LN incur higher annual and 5-year cumulative costs. By estimating the expected duration in each renal function state and incorporating associated annual costs, disease severity at presentation can be used to anticipate future healthcare costs, critical knowledge for cost effectiveness evaluations of novel LN therapies.
To cite this abstract in AMA style:
Barber M, Hanly JG, O'Keeffe A, Su L, Urowitz M, St. Pierre Y, Romero-Diaz J, Gordon C, Bae SC, Bernatsky S, Wallace DJ, Merrill JT, Isenberg DA, Rahman A, Ginzler EM, Fortin PR, Gladman DD, Sanchez-Guerrero J, Petri M, Bruce IN, Dooley MA, Ramsey-Goldman R, Aranow C, Alarcon GS, Chatham WW, Steinsson K, Nived O, Sturfelt GK, Manzi S, Khamashta M, van Vollenhoven RF, Zoma A, Ramos-Casals M, Ruiz-Irastorza G, Lim SS, Stoll T, Inanc M, Kalunian KC, Kamen DL, Maddison P, Peschken CA, Jacobsen S, Askanase A, Buyon JP, Theriault C, Thompson K, Farewell V, Clarke AE. Economic Evaluation of Lupus Nephritis in an International Inception Cohort: Comparing the Hospitalization, Medication, Dialysis, and Procedure Costs of Those with and without Nephritis [abstract]. Arthritis Rheumatol. 2015; 67 (suppl 10). https://acrabstracts.org/abstract/economic-evaluation-of-lupus-nephritis-in-an-international-inception-cohort-comparing-the-hospitalization-medication-dialysis-and-procedure-costs-of-those-with-and-without-nephritis/. Accessed .« Back to 2015 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/economic-evaluation-of-lupus-nephritis-in-an-international-inception-cohort-comparing-the-hospitalization-medication-dialysis-and-procedure-costs-of-those-with-and-without-nephritis/