Cost-effective analysis of hepatitis A prevention in Ireland

OBJECTIVE: The purpose of this study was to determine the most cost-effecti ve prevention strategy against hepatitis A virus (HAV) infection for health care workers and the general population at risk in Ireland. METHODS: Four prevention strategies were compared: active immunization with Havrix Monodose (1440E.U); screening for anti-HAV antibody and then vaccin ating; pas sive immunization; screening for anti-HAV antibody and then pass ive immunization. The cost-effective ratio was calculated for each preventi on strategy. Threshold analysis, sensitivity analysis, and model extension to include indirect cost from work days lost and secondary attack rates thr ough horizontal transmission were also derived. RESULTS: The medical costs were lowest and the infection rate highest when no preventive action was taken. Vaccination was most cost effective when th e prevalence of immunity was 45% or less, reducing the infection rate by 98 % when compared to nonprevention. Screening before vaccination was most cos t effective when the prevalence of immunity was seater than 45%. Passive im munization and screening before passive immunization were not comparable to the other strategies in cost effectiveness. Sensitivity analysis showed th at the cost-effective ratio for vaccination was dependent on vaccine price, incidence of HAV, and prevalence of immunity in the target group. Extendin g the model to include indirect costs further increased the cost effectiven ess of vaccination. CONCLUSION: The best cost-effective strategy relates to target group immuni ty. Where HAV immunity is 45% or less, vaccination is the strategy of choic e and when immunity is greater than 45%, then screening followed by vaccina tion should be used. This study can be used to provide a framework within w hich choices can be made to achieve better health for less cost. (Am J Gast roenterol 2000,95:223-226. (C) 2000 by Am. Cell, of Gastroenterology)