THU0287 Clinical and Economic Burden of Patients with Microscopic Polyangiitis (MPA) in the United States
Authors: K. Raimundo, A. Farr, G. Kim, G. Duna
Journal: Annals of the Rheumatic Diseases (2015)

<h3>Objectives</h3> The objectives of this analysis were to develop an algorithm to identify microscopic polyangiitis (MPA) in administrative claims data based on experts9 input, as there is no specific ICD-9-CM diagnosis code for MPA, and to describe the clinical and economic burden of patients with MPA. <h3>Methods</h3> The analysis utilized Truven Health Analytics9 MarketScan® Commercial and Medicare Supplemental administrative claims databases. Patients with ≥2 claims with a diagnosis of ICD-9-CM 447.6 arteritis, unspecified were identified between 7/1/2010 and 6/30/2012. Patients were required to be ≥18 years old at first diagnosis, have continuous enrollment for ±6 months around first diagnosis (pre/peri-period and post-period), have no claims with an arteritis (447.6) diagnosis in the pre/peri-period and have no claims with a granulomatosis with polyangiitis (GPA) diagnosis (ICD-9-CM 446.4), hepatitis B diagnosis or hepatitis C diagnosis during the pre/peri-period or post-period. Lastly, to increase the likelihood of capturing true MPA patients, patients were required to have a claim with a diagnosis for renal failure, glomerulonephritis or hemoptysis during the pre/peri-period or post-period. Clinical characteristics, specifically major relapse-associated conditions informed by the Birmingham Vasculitis Activity Score, were identified based on the presence of a relevant diagnosis on claims. All-cause healthcare resource utilization and costs were measured for the following categories: inpatient admissions, emergency room visits, outpatient office visits/outpatient services and outpatient prescription medications. Costs are presented in 2013 US$. <h3>Results</h3> There were 8390 patients with ≥2 claims with a diagnosis of arteritis, unspecified. After applying the inclusion and exclusion criteria, the final sample was 612 newly diagnosed MPA patients. The average age at diagnosis was 62 years (standard deviation [SD] 16) and 38% of patients were male). Results are presented in Table 1. Patients had evidence of major relapse-associated conditions before and after MPA diagnosis. All-cause healthcare costs nearly doubled following an MPA diagnosis, with costs related to inpatient admissions being the main driver before and after diagnosis. <h3>Conclusions</h3> Patients with MPA were identified in these databases using a new algorithm, developed via clinical input, based on the presence of a non-specific diagnosis code and diagnoses of additional conditions associated with more severe disease. Receiving a diagnosis of MPA was associated with an increase in all-cause healthcare resource utilization and costs, primarily attributable to an increase in costs of inpatient admissions. Future studies are needed to explore whether similar trends are seen in other countries. <h3>Disclosure of Interest</h3> K. Raimundo Employee of: Genentech, Inc., A. Farr Employee of: Truven Health Analytics which performs consulting work for pharmaceutical companies, including Genentech, G. Kim Employee of: Truven Health Analytics which performs consulting work for pharmaceutical companies, including Genentech, G. Duna Employee of: Genentech, Inc.