Cost of illness of invasive meningococcal disease caused by serogroup B Neisseria meningitidis in Spain.

Introduction: Invasive meningococcal disease (IMD) is a severe infectious disease, mainly affecting children under 5 years, associated with long-term physical, neurological and psychological sequelae. In Spain, most IMD cases are caused by meningococcal serogroup B (MenB). This study estimates its economic burden from a societal perspective in Spain.

Methods: A previously published bottom-up, model-based incidence costing approach by Scholz et al. (2019) to estimate the economic burden of MenB in Germany was adapted to the Spanish setting. Diagnosis and age-related costs for a hypothetical Spanish cohort were calculated over a lifetime horizon. Official Spanish databases, literature and expert opinion were used as data sources. The costs were updated to 2019 prices, and a 3% discount rate was applied. Direct costs related to the acute IMD phase, long-term sequelae, rehabilitation and public health response were considered. Indirect costs included productivity losses and premature mortality and were calculated using the human-capital approach (HCA) and friction-cost approach (FCA). Deterministic and probabilistic sensitivity analyses were also performed.

Result: At base-case, the total cost for a cohort of 142 patients (2017-2018 period) was €4.74 million (€33,484/case) using the FCA and €13.14 million (€92,768/case) using the HCA. Direct costs amounted to €4.65 million (€32,765/case). Sequelae costs represented 62.46% of the total cost using the FCA and 77.63% using the HCA. Deterministic sensitivity analysis showed that variation of ± 20% in the input parameter values (population, epidemiology, productivity, costs) had the greatest influence on the base-case results, and the probabilistic sensitivity analysis showed the probability of fitting base-case estimates was > 99%, both for FCA and HCA.

Discussion: MenB IMD is an uncommon but severe disease, with a high economic burden for Spanish society. The elevated costs per IMD case reflect its severity in each patient suffering this disease, especially due to the development of sequelae.