Reduction of Direct Health Costs Associated with Pertussis Vaccination with Acellular Vaccines in Children Aged 0–9 Years with Pertussis in Catalonia (Spain)

OBJECTIVES: The aim of this study was to assess direct health costs in children with pertussis aged 0–9 years who were vaccinated, partially vaccinated, and unvaccinated during childhood, and to assess the association between pertussis costs and pertussis vaccination in Catalonia (Spain) in 2012–2013. METHODS: Direct healthcare costs included pertussis treatment, pertussis detection, and preventive chemotherapy of contacts. Pertussis patients were considered vaccinated when they had received 4–5 doses, and unvaccinated or partially vaccinated when they had received 0–3 doses of vaccine. The Chi square test and the odds ratios were used to compare percentages and the t test was used to compare mean pertussis costs in different groups, considering a p < 0.05 as statistically significant. The correlation between pertussis costs and study variables was assessed using the Spearman’s ρ, with a p < 0.05 as statistically significant. Multiple linear regression analysis (IBM-SPSS program) was used to quantify the association of pertussis vaccination and other study variables with pertussis costs. RESULTS: Vaccinated children with pertussis aged 0–9 years had significantly lower odds ratios of hospitalizations (OR 0.02, p < 0.001), laboratory confirmation (OR 0.21, p < 0.001), and severe disease (OR 0.02, p < 0.001) than unvaccinated or partially vaccinated children with pertussis of the same age. Mean direct healthcare costs were significantly lower (p < 0.001) in vaccinated patients (€190.6) than in unvaccinated patients (€3550.8), partially vaccinated patients (€1116.9), and unvaccinated/partially vaccinated patients (€2330). Multivariable linear regression analysis showed that pertussis vaccination with 4–5 doses was associated with a non-significant reduction of pertussis costs of €107.9 per case after taking into account the effect of other study variables, and €200 per case after taking into account pertussis severity. CONCLUSIONS: Direct healthcare costs were lower in children with pertussis aged 0–9 years vaccinated with 4–5 doses of acellular vaccines than in unvaccinated or partially vaccinated children with pertussis of the same age.