Economic Evaluation of Intravenous Immunoglobulin plus Corticosteroids for the Treatment of Steroid-Resistant Chronic Inflammatory Demyelinating Polyradiculoneuropathy in Thailand

Background and Objective: Intravenous immunoglobulin (IVIG) has been recommended for steroid-resistant chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). The treatment, however, is very costly to healthcare system, and there remains no evidence of its economic justifiability. This study aimed to conduct an economic evaluation (EE) of IVIG plus corticosteroids in steroid-resistant CIDP in Thailand. Methods: A Markov model was constructed to estimate the lifetime costs and outcomes for IVIG plus corticosteroids in comparison with immunosuppressants plus corticosteroids in steroid-resistant CIDP patients from a societal perspective. Efficacy and utility data were obtained from clinical literature, meta-analyses, medical record reviews, and patient interviews. Cost data were obtained from list prices, an electronic hospital database, published source, and patient interviews. All costs [in 2015 US dollars (US$)] and outcomes were discounted at 3 % annually. One-way and probabilistic sensitivity analyses were conducted. Results: In the base-case, the incremental costs and quality-adjusted life years (QALYs) of IVIG plus corticosteroids versus immunosuppressants plus corticosteroids were US$2112.02 and 1.263 QALYs, respectively, resulting in an incremental cost-effectiveness ratio (ICER) of US$1672.71 per QALY gained. Sensitivity analyses revealed that the utility value of disabled patients was the greatest influence on ICER. At a societal willingness-to-pay threshold in Thailand of US$4672 per QALY gained, IVIG plus corticosteroids had a 92.1 % probability of being cost effective. Conclusions: At a threshold of US$4672 per QALY gained, IVIG plus corticosteroids is considered a cost-effective treatment for steroid-resistant CIDP patients in Thailand.