DIRECT AND INDIRECT COSTS ASSOCIATED WITH DAMAGE ACCRUAL: RESULTS FROM THE SYSTEMIC LUPUS INTERNATIONAL COLLABORATING CLINICS (SLICC) INCEPTION COHORT

O030 / #400

Topic: AS23 - SLE-Diagnosis, Manifestations, & Outcomes

ABSTRACT CONCURRENT SESSION 05: EMERGING INSIGHTS ON THE MANAGEMENT OF LUPUS MANIFESTATIONS AND COMORBIDITIES

23-05-2025 1:40 PM - 2:40 PM

Background/Purpose We described the direct healthcare costs associated with damage accrual in patients in the Systemic Lupus International Collaborating Clinics (SLICC) Inception Cohort.[1] However, our estimates only included partial direct costs and indirect costs from lost productivity were not included. We supplemented our primary data by querying a cohort subset on all healthcare use and lost time in paid/unpaid labor and provide estimates of complete direct and indirect costs for the full cohort, stratified by damage.

Methods Between 1999 and 2011, SLE patients from 31 centers in 10 countries were enrolled into the SLICC Inception Cohort within 15 months of diagnosis and data on disease damage (SLICC/ACR Damage Index [SDI]) and limited healthcare use (ie, hospitalizations, medications, and dialysis) were collected annually through to July 2022. Starting in 2015, 18 sites collected supplemental economic data annually (ie, visits to physicians, nonphysician healthcare professionals, and the emergency room, laboratory tests, radiological/other diagnostic procedures, outpatient surgeries, help obtaining medical care, and lost time in paid/unpaid labor). Direct costs were calculated by multiplying each health resource by its corresponding 2023 Canadian unit cost. Total indirect costs included: 1) absenteeism (time lost from paid labor because of illness), 2) presenteeism (degree of patient self-reported productivity impairment in paid/unpaid labor, based on a visual analog scale), and 3) opportunity costs (additional time patients would be working in paid/unpaid labor if not ill). Opportunity costs were calculated as the difference between the time patients reported working vs that worked by an age, sex, and geographic-matched general population in paid/unpaid labor. Indirect costs from paid/unpaid labor were valued using age-and-sex-specific wages from Statistics Canada. Multiple imputation was used to predict missing cost values for the patients in the full cohort who provided only utilization data for hospitalizations, medications, and dialysis for all observations. At each assessment, patients were assigned to one of 6 damage states (ie, SDI = 0, 1, 2, 3, 4, ≥ 5) and annual costs, both unimputed and including imputations, were stratified by SDI score. Means and 95% confidence intervals were computed and compared.

Results 1694 patients (88.8% female, 48.9% White, mean age at diagnosis 34.6 years, mean disease duration at cohort enrollment 0.5 years), were followed for a mean of 10.5 (SD 5.3) years. Of these 1694 patients, 766 (89.7% female, 41.4% White, mean age at diagnosis 33.0 years, mean disease duration at cohort enrollment 0.4 years) completed the supplemental economic questionnaire. Their mean disease duration at the time of introduction of the supplemental questionnaire was 10.9 (range 3.9-19.5) years and this cohort subset provided this additional economic data for a mean of 3.5 (SD 1.9) years. Among the cohort subset completing the supplemental economic questionnaire, on average, indirect costs, primarily from unpaid labor, accounted for 81.1% of total costs (Table 1). For the full cohort, annual direct and indirect costs increased with increasing SDI (SDI=0: total costs $33,812 [95% CI $31,088, $36,537]; SDI ≥ 5: total costs $90,839 [95% CI $82,275, $99,403]) (Table 2).

Conclusions Patients with the highest vs the lowest SDIs incurred complete direct costs that were 5.9-fold higher and indirect costs 2.1-fold higher. However, patients with no or minimal damage still experienced considerably reduced productivity. Indirect costs exceeded direct, on average, by 4.5-fold, underscoring the importance of incorporating lost productivity in estimating the economic burden of SLE. References: [1.] Barber MRW. Arthritis Care Res 2020;72:1800-8.