A longitudinal analysis of costs associated with change in disease activity in systemic lupus erythematosus

J Med Econ. 2013;16(6):793-800. doi: 10.3111/13696998.2013.802241. Epub 2013 May 15.


Objectives: To estimate the economic consequences of changes in disease activity on healthcare resource utilization (HRU) and costs.

Methods: A retrospective longitudinal study of systemic lupus erythematosus (SLE) patients receiving care in a regional integrated health delivery system in the US from 01/2004 through 03/2011 was conducted using electronic health records, medical chart reviews, and claims. Eligible patients were ≥18 years old, with ≥1 rheumatologist-confirmed SLE diagnosis and ≥1 eligible rheumatology encounter. Patients were continuously enrolled ≥90 days before and ≥30 days after the encounters. Charts were manually reviewed to estimate SLEDAI scores. Average unit costs of each medical procedure, facility use, and prescription were estimated from a payer perspective (2011 USD) using a managed care claims database. HRU and costs were calculated for the 30-day period surrounding every SLEDAI score date (10 days before and 19 after). Relationships between HRU/costs and SLEDAI scores were estimated using mixed-effect models.

Results: Overall, 178 SLE patients were included; mean age was 50.6 years, 91% were female, and 95.5% Caucasian. Patients had a total of 1343 encounters with SLEDAI scores over an average period of 1035 days. Reductions of SLEDAI scores were associated with reductions in HRU and costs. SLEDAI score reductions of 4-points were associated with reductions of 10% HRU and 14% costs over a 30-day period; reductions of 8-points had associated reductions of 19% HRU and 26% costs; and reductions of 10-points had associated reductions of 23% HRU and 31% costs. Annualized, changes in SLEDAI scores are associated with changes of $2485 (SLEDAI score change: 10-6), $4624 (10-2), and $5579 (10-0), respectively.

Conclusion: Reductions in disease activity were associated with substantial reductions of HRU and costs.

Limitations: Only short-term effects of disease activity change were investigated, disregarding other potential benefits of low disease activity on long-term organ damage prevention or comorbidities.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Costs and Cost Analysis
  • Female
  • Health Services / economics*
  • Health Services / statistics & numerical data*
  • Humans
  • Insurance Claim Review
  • Longitudinal Studies
  • Lupus Erythematosus, Systemic / economics
  • Lupus Erythematosus, Systemic / pathology*
  • Male
  • Medical Audit
  • Middle Aged
  • Quebec
  • Retrospective Studies
  • Severity of Illness Index*
  • Young Adult