Estudio coste-beneficio de la vacunación contra varicela en Aragón / A cost-benefit analysis of varicella vaccination in Aragón

Fundamento. La varicela, enfermedad infecto-contagiosa que afecta a la infancia de forma benigna, puede complicarse en adultos y niños vulnerables y ser mortal. Existen vacunas eficaces. Se estudiaron retrospectivamente los costes que supuso esta enfermedad en la población aragonesa en el período 2004-2014 y las hospitalizaciones generadas. Se compararon con los gastos que supondría haber vacunado a esas personas y también los gastos de vacunar a la población de 1 año de edad durante todo ese período. Mediante un análisis coste-beneficio, se evaluó el impacto económico de la vacunación. Método. Se utilizaron datos de la Autonomía de Aragón (España) de estos 11 años (incidencia anual de varicela, altas hospitalarias por este motivo, precio de la consulta de atención primaria y de hospitalización de cada año, así como el coste de días de trabajo según el salario mínimo anual y medicaciones utilizadas). Se calcularon los costes capitalizados, se compararon con los gastos capitalizados de vacunación y se realizó un análisis de sensibilidad. Resultados. Se obtuvo un índice beneficio-coste de 1,6 vacunando y revacunando a todos los niños que se enfermaron. Resultó un índice beneficio-coste de 1,24 al vacunar a toda la población de 12 meses con vacuna de 28,59€. En estos 11 años, el 53% de las hospitalizaciones fueron niños menores de 5 años. Conclusiones. Las campañas públicas de vacunación con 2 dosis a población menor de 4 años suponen ahorro y rentabilidad porque el precio de la vacuna permite un índice beneficio-coste superior a 1. Es esperable una gran disminución de hospitalizaciones en la población de 3-4 años.

Background. Varicella, a contagious and infectious disease that is usually benign in children, may become complicated among adults and vulnerable children and may even be life-threatening. There are effective vaccines. A retrospective study was conducted about costs and resulting hospitalizations related to this disease in the population of Aragón in the 2004-2014 period. Costs were compared to the expenses that would have been incurred if those people had received the vaccine and also to the expenses of vaccinating the 1-year-old population over the entire period. A cost-benefit analysis was done to assess the economic impact of varicella vaccination. Method. Data for the 11-year period were provided by the Autonomous Community of Aragón (Spain) and included annual varicella incidence, hospital discharges of varicella cases, costs of primary health care visits and hospitalizations for each year, costs of each workday as per the minimum annual salary and of drugs used). Capitalized costs were estimated and compared to capitalized expenses of vaccination, and a sensitivity analysis was performed. Results. A benefit-cost ratio of 1.6 was obtained considering that all children who had varicella had been vaccinated and had received a booster dose. A benefit-cost ratio of 1.24 was obtained considering that the vaccine had been administered to every 1-year-old individual at a price of EUR 28.59 per vaccine. Over the 11-year period, 53% of hospitalizations corresponded to children younger than 5 years old. Conclusions. Public campaigns for the immunization of children younger than 4 years old with 2 doses lead to cost savings and are cost-effective because the vaccine price results in a benefit-cost ratio greater than 1. A major reduction is expected in the number of hospitalizations among children aged 3-4 years.

Impact of methodology on the results of economic evaluations of varicella vaccination programs: is it important for decision-making? / Impacto da metodologia nos resultados de avaliações econômicas de programas de vacinação da varicela: é importante para o processo de tomada de decisão?

This study aims to review the literature on economic evaluation of childhood varicella vaccination programs and to discuss how heterogeneity in methodological aspects and estimation of parameters can affect the studies' results. After applying the inclusion criteria, 27 studies published from 1980 to 2008 were analyzed in relation to methodological differences. There was great heterogeneity in the perspective adopted, evaluation of indirect costs, type of model used, modeling of the effect on herpes zoster, and estimation of vaccine price and efficacy parameters. The factor with the greatest impact on results was the inclusion of indirect costs, followed by the perspective adopted and vaccine price. The choice of a particular methodological aspect or parameter affected the studies' results and conclusions. It is essential that authors present these choices transparently so that users of economic evaluations understand the implications of such choices and the direction in which the results of the analysis were conducted.

O presente trabalho tem por objetivo rever a literatura sobre avaliação econômica de programas de vacinação infantil contra varicela, e discutir como a heterogeneidade em aspectos metodológicos e na estimativa dos parâmetros pode afetar os resultados dos estudos. Após aplicação dos critérios de inclusão, 27 estudos do período de 1980 a 2008 foram analisados com relação às diferenças metodológicas. Observou-se grande heterogeneidade na perspectiva adotada, valoração dos custos indiretos, tipo de modelo empregado, modelagem do efeito no herpes zoster, e na estimativa dos parâmetros de preço e eficácia da vacina. O fator que mais impactou os resultados foi a inclusão dos custos indiretos seguido da perspectiva e preço de vacina adotados. A escolha de um determinado aspecto metodológico ou parâmetro afetou os resultados e conclusões dos estudos. É de fundamental importância que os autores apresentem essas escolhas com transparência para que os usuários das avaliações econômicas compreendam as repercussões dessas escolhas, e em qual direção os resultados das análises foram conduzidos.

Varicella epidemiology and cost-effectiveness analysis of universal varicella vaccination program in Taiwan.

Varicella zoster virus is highly contagious and affects people worldwide. In this study, we collected local epidemiological data and evaluated the cost-effectiveness of varicella vaccination program in Taiwan. To examine the economical consequences of universal vaccination, a model of the incidence and the associated costs in a hypothetical cohort was created each year for 30 years. The incidence increased sharply after the infancy and peaked in children aged 5 years. The hospitalization rate among cases was the highest in infants, followed by adults 30 to 44 years old. The benefit-cost analysis showed that one dollar invested in the program would cost extra 46 cents in direct medical expense, but would save extra 45 cents considering the societal expenses. Substantial economical benefits can occur due to the averted unproductive days for parents. Sensitive surveillance of both varicella and zoster is essential in countries that have implemented or are about to implement varicella vaccination.

Costs and benefits of varicella screening and vaccination for healthcare workers at a general hospital

To demonstrate the costs and benefits of screening and vaccinating varicella-susceptible healthcare personnel at a general hospital with live attenuated varicella-zoster virus vaccine. Screening of healthcare workers at Almana General Hospital, Al-Khobar, Dammam for varicella-zoster antibody by indirect fluorescent antibody. Out of 757 healthcare workers, 511 [62.5%] had a definite history of varicella-zoster virus infection in the past. Of 161 healthcare workers with no history of varicella-zoster virus infection, 129 [80%] were positive for varicella-zoster antibody when tested by indirect fluorescent antibody. There were 28 cases of chickenpox among hospital staff in one year, and they were excluded from contact with patients for 5-7 days each. Adopting varicella screening and vaccination of susceptible healthcare workers in a general hospital would be cost-effective and will result in improved patient care