Economic evaluation of different modalities of immunoglobulin therapy in chronic dysimmune polyradiculoneuropathies

Lifelong and expensive immunoglobulin administration is the main therapy for chronic dysimmune polyneuropathies as chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and multifocal motor neuropathy (MMN). Based on recent clinical evidence, this treatment can be administered by intravenous immunoglobulin (IVIg) or subcutaneous infusions (SCIg) and delivered at home. IVIg, in responsive and stabilized patients, is usually administered in an outpatient setting with twice a month infusion every 25–35 days (1–2 g/Kg/month). Conversely, SCIg is given at home in most cases with three to five weekly infusions (1–2 g/Kg/month). This study aims to determine whether SCIg is cost-effective compared with IVIg from a regional health service perspective. First, costs were calculated through simulation testing different hypotheses on cost drivers. Secondly, costs were estimated on the basis of field data collected from our patients. We considered only direct medical costs. The results of the simulation show that the yearly direct costs to treat a patients were € 43,456 (IVIg) and € 42,772 (SCIg). Ig acquisition costs were the main cost driver; it represented respectively 97% (SCIg) and 93% (IVIg) of the total cost. 3%only is due to the cost of medical and nursing staff (IVIg) and 3% is due to the cost of IVIg’s side effect treatment: this cost is absent for SCIg. Estimation made from the field data were found to be little different: over 6 months the total mean cost was € 21,088 (IVIg) and € 20,878 (SCIg). Our pilot study documents the existence of two treatments, SCIg and IVIg, substantially equivalent as efficacy and costs for treating chronic dysimmune neuropathies.