The economic burden of CIDP in the United States: A case-control study

BACKGROUND: Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare neurological disorder of the peripheral nervous system. The economic burden of CIDP is not well understood. OBJECTIVES: To assess the economic and clinical burden of CIDP and to compare the incremental burden relative to a matched control group without CIDP. METHODS: This retrospective case-control analysis was conducted using data from the IQVIA Real-World Data Adjudicated Claims. Adults newly diagnosed with CIDP between 7/1/2010 and 6/30/2014 were identified and direct matched to controls without CIDP. Baseline characteristics were assessed and compared over a 6-month pre-index period. Healthcare resource use, costs and clinical characteristics were assessed and compared over a 2-year follow-up. Total cost differences over the 2-year follow-up were compared between matched cohorts using a generalized estimating equation model. RESULTS: The final sample comprised a total of 790 cases matched to 790 controls. Over the 2-year follow-up, cases more frequently experienced neuropathic pain, back pain and osteoarthritis and more commonly utilized opioids, anti-convulsants and anti-depressants. Compared to controls, more cases had ≥1 hospitalization (26.2% vs. 9.0%), and cases had a higher mean number of outpatient prescription fills (62.8 vs. 32.0) and physician office visits (34.7 vs. 13.0) (all p<0.0001). Cases had 7.5x higher mean total costs ($116,330 vs. $15,586, p<0.0001). Important cost drivers were costs for outpatient ancillary, radiology and HCPCS drugs (mean $76,366 vs. $4,292) and costs for inpatient care (mean $16,357 vs. $2,862) (both p<0.0001). Among cases, CIDP therapy (inclusive of both outpatient pharmacy and medical claims) accounted for 51.2% of mean total costs. After further adjusting for baseline clinical characteristics, cases were associated with a 6.1x increase in total costs compared to controls (p<0.0001). CONCLUSIONS: Our findings suggest a substantial clinical and economic burden among patients with CIDP relative to matched controls over a 2-year follow-up.