Direct Medical Cost of Renal Flare in Lupus Nephritis

Kenneth Kalunian; David Ward; Thomas Bramley; Marta Juhasz; Andrew Wiseman; Niv Caviar; Jim Beitel; Peter Potgieter; Ellen M. Ginzler

Background / Purpose: The occurrence of flares in patients with lupus nephritis (LN) may result in additional medication use, diagnostic procedures, visits to healthcare providers, and hospitalization. This study retrospectively analyzes the direct healthcare costs associated with renal flares in patients with lupus nephritis using a US health insurance claims database.

Methods: Data was obtained from the PharMetrics Integrated Medical and Pharmaceutical Database, an integrated database of pharmacy and medical claims from approximately 85 US commercial health plans. We analyzed patients who were continuously enrolled for a minimum of 18 months during the time period 1/1/01 to 1/1/06. Patients with LN were identified using ICD-9 diagnosis code for lupus (710.0) AND one of the following codes for renal involvement or acute renal failure (581.81, 582.81, 583.81, 584.x, 586.x, or 593.9). As no code for renal flare exists, renal flares were identified based on both of the following activities occurring within 14 days: 1) renal procedure common for LN flare such as 24 hour urine or nephrology consult, AND 2) prescription activity including prednisone > 40 mg / day or new use of MMF, AZA, or CTX. CNS flares were excluded using common CNS procedure codes and / or prescription activity.

Results: Of the 2,101 patients who were continuously enrolled for 18 months and who met the study criteria for LN, 376 experienced a renal flare based on the study criteria. The direct costs for 12 months in LN patients not experiencing a renal flare were an average of $29,153 per patient. The direct costs for 12 months following the occurrence of a renal flare were an average of $54,954 per patient, an increase of $25,801 compared to LN patients not experiencing a renal flare. This difference resulted from substantial increases in claims activity during the 12 months following an identified renal flare: 1) labs (+136%), physician visits (+66%), emergency room visits (+ 84%), hospitalization (+160%), and medication use (+87%).

Conclusion: The occurrence of renal flare in lupus nephritis results in substantial direct healthcare costs with an average direct cost per renal flare of over $25,000 in this analysis. Hospitalization is the largest cost component followed by physician visits, medication use, labs, and emergency room visits. Reducing the occurrence and / or magnitude of renal flare may result in substantial savings in direct medical costs.

Disclosure: All authors were employees or consultants of La Jolla Pharmaceutical Company.

American Society of Nephrology
Saturday, November 3, 2007 10:00 AM
Poster Session: Outcomes and Treatments in the Glomerular Diseases (10:00 AM-12:00 PM)
Poster Board Number: SA-PO1019