Long‐term medical costs and resource utilization in systemic lupus erythematosus and lupus nephritis: A five‐year analysis of a large medicaid population

Abstract

Objective. To estimate the long-term direct medical costs and health care utilization for patients with systemic lupus erythematosus (SLE) and a subset of SLE patients with nephritis. Methods. Patients with newly active SLE were found in the MarketScan Medicaid Database (1999 -2005), which includes all inpatient, outpatient, emergency department, and pharmaceutical claims for more than 10 million Medicaid beneficiaries. The date a patient became newly active was defined as the earliest observed SLE diagnosis code, with a 6-month clean period prior to the diagnosis. This method identified 2,298 patients with a consecutive followup of 5 years. A reference group of patients without SLE was constructed using propensity score matching. Nephritis was assessed based on diagnosis and procedure codes involving the kidney. Results. Mean annual medical costs for SLE patients totaled $16,089 at year 1, which is significantly greater (by $6,831) than that for reference patients. Costs decreased slightly at year 2 but then increased yearly at an average rate of 16% through year 5, to $23,860. SLE patients without nephritis (n ‫؍‬ 1,809) had costs $967-3,756 higher than the reference patients. SLE patients with nephritis (n ‫؍‬ 489) had costs $13,228 -34,907 greater than the reference group. Inpatient visits for the nephritis subgroup were 0.6 -1.0 per capita, which are approximately twice the rate for all SLE patients and 3 to 4 times higher than the reference group. Conclusion. SLE is a costly condition to treat. Medical expenses incurred by SLE patients increase steadily over time, particularly for patients with nephritis.

A structured literature review of the direct costs of adult systemic lupus erythematosus in the US

“…Li et al reported that SLE patients with nephritis incurred annual costs $13,228 -$34,907 greater than control patients. Similar to the findings reported by Pelletier et al, inpatient visits for nephritis patients were 0.6 -1.0 per capita, approximately twice the rate for all SLE patients and nearly 4 times higher than the reference group (21,27). Patients with nephritis who did not progress to end-stage renal disease (ESRD) over the 5-year study period generated costs similar to the overall SLE population in the first 3 years; however, costs increased in years 4 and 5 to 46 -61% greater than the overall SLE group.…”

“…Four relevant populations were examined: 1) SLE patients in general (including those both with and without nephritis, as well as other disease manifestations and comorbidities), 2) SLE patients with nephritis, 3) SLE patients without nephritis, and 4) matched controls (propensity score matched on key demographic variables). Several studies examined more than 1 population subgroup, although only 2 articles reported cost information for all 4 subgroups (Li et al, 2009 [21], and Carls et al, 2009 [16]), and both studies were based on retrospective claims analyses that used propensity score matching in order to define the reference (control) group. No disease manifestations other than nephritis were explicitly studied.…”

“…Three of the 7 studies utilized a longer timeframe, with Li et al examining costs on an annual basis over 5 years and both studies by Clarke et al reporting cumulative 4-year costs from the Tri-Nation Study (18,19,21). The methodology for identifying SLE patients was consistent across studies; those using claims data generally used International Classification of Diseases, Ninth Revision (ICD-9) codes (710.0x) to identify potential patients, with patients being required to have at least 1 inpatient or 2 outpatient claims at least 30 days apart in order to exclude "rule-out" diagnoses.…”

“…Patient self-reported resource utilization resulted in lower cost estimates versus claims analyses. Medicaid claims analyses generated lower incremental cost estimates for SLE patients versus controls compared with commercial claims analyses ( Table 2) (21).…”

“…In all SLE patients, mean reported annual direct costs were $17,009 as compared with a median cost of $8,407. In patients with nephritis, mean and median costs were $29,034 and $14,672, respectively (21).…”