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OBJECTIVE: To revise the available evidence on the cost-effectiveness of antiviral regimens for treatment of chronic hepatitis B. MATERIAL AND METHODS: We performed a systematic revision on MEDLINE, LILACS NICE and COCHRANE databases, searching for economic evaluations of antiviral regimens for treatment of chronic hepatitis B. We included original studies, systematic revisions and management guidelines including information on the cost-effectiveness of this treatment. We registered the characteristics and results of the retrieved documents. RESULTS: We obtained 29 original papers, 4 revision articles and 4 management guidelines. Most of these publications have been done in the last 5 years. There was conflict of interest in 73% of original articles, due to authors working for the pharmaceutical industry. 93% of articles that evaluate the cost-effectiveness of giving treatment for chronic hepatitis B against management of its complications find that it is indeed cost-effective to give antiviral treatment. 3/6 studies that evaluate lamivudine against other drugs find it as a dominant strategy, 3/5 find entecavir as the dominant strategy, 1/1 find tenofovir dominant, » find conventional interferon as dominant and none of them find adefovir or pegylated interferon as dominant strategies. CONCLUSIONS: We consider that the available evidence suggests that to give antiviral treatment for chronic hepatitis B is a cost-effective intervention for many health systems, including ours. It has varying indexes of cost-effectiveness according to the evaluated regimens. Ideally , we should perform local economic evaluations in this issue.

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There is wide controversy about the mechanism of action of the levonorgestrel used for emergency oral contraception, and many organizations, both scientific as well as from the civil society, show their discrepancy with its use, due to its possible action as an abortion- inducer. In order to evaluate the scientific evidence available on the mechanisms of action of the levonorgestrel used for emergency oral contraception (EOC), a systematic revision was performed in the Medline and Cochrane library databases. We found 444 articles. After reviewing the abstracts, we selected 22 articles, whose complete texts were evaluated. We found that the main mechanism of action of the levonorgestrel, given at the doses recommended for EOC, is the inhibition or retardation of the ovulation, it doesn't affect the spermatozoa in their migration or egg-penetration capacities. No morphological or molecular alterations in the endometrium that could interfere with the implantation of the fertilized egg have been demonstrated. There is no actual scientific evidence available supporting that the use of levonorgestrel for EOC is abortive.

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Existe amplia controversia acerca del mecanismo de acción del levonorgestrel como anticonceptivo oral de emergencia; numerosas organizaciones, tanto científicas como de la sociedad civil, muestran su disconformidad con su uso, debido a su posible acción como inductor de aborto. Con el objetivo de evaluar la evidencia científica disponible sobre los mecanismos de acción del levonorgestrel utilizado como anticonceptivo oral de emergencia (AOE), se realizó una revisión sistemática en las bases de datos Medline y Cochrane Library donde se encontró 444 artículos; después de revisar los resúmenes, se seleccionó 22 artículos, los cuales fueron evaluados a texto completo. Se encontró que el principal mecanismo de acción del levonorgestrel, a las dosis recomendadas como AOE, es la inhibición o retraso de la ovulación; no afecta a los espermatozoides en su capacidad de migración ni de penetración al óvulo. No se ha demostrado alteraciones morfológicas ni moleculares en el endometrio que puedan interferir con la implantación del huevo fecundado. No existe evidencia científica actual disponible que sustente que el uso de levonorgestrel como AOE sea abortivo.

There is wide controversy about the mechanism of action of the levonorgestrel used for emergency oral contraception, and many organizations, both scientific as well as from the civil society, show their discrepancy with its use, due to its possible action as an abortion-inducer. In order to evaluate the scientific evidence available on the mechanisms of action of the levonorgestrel used for emergency oral contraception (EOC), a systematic revision was performed in the Medline and Cochrane library databases. We found 444 articles. After reviewing the abstracts, we selected 22 articles, whose complete texts were evaluated. We found that the main mechanism of action of the levonorgestrel, given at the doses recommended for EOC, is the inhibition or retardation of the ovulation, it doesn't affect the spermatozoa in their migration or egg-penetration capacities. No morphological or molecular alterations in the endometrium that could interfere with the implantation of the fertilized egg have been demonstrated. There is no actual scientific evidence available supporting that the use of levonorgestrel for EOC is abortive.

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Objetivo. Revisar la evidencia disponible acerca de la costo-efectividad de los regímenes antivirales en el tratamiento de la hepatitis B crónica. Material y Métodos. Se realizó una revisión sistemática de las bases de datos de MEDLINE, LILACS, NICE guidelines y COCHRANE sobre evaluaciones económicas de regímenes antivirales para el tratamiento de hepatitis B crónica. Se incluyó los estudios originales, revisiones sistemáticas y guías de manejo conteniendo información acerca de la costo-efectividad de dicho tratamiento. Se registró las características y resultados de los documentos obtenidos. Resultados. Se obtuvo 29 artículos originales, cuatro artículos de revisión y cuatro guías de manejo clínico. La mayoría de las publicaciones fueron hechas en los cinco últimos años. Los autores tenían conflicto deinterés, por trabajar en la industria farmacéutica, en 73 por ciento de los artículos originales. El 93 por ciento de los artículos que evalúan costo-efectividad de brindar tratamiento para hepatitis B crónica frente a manejo de complicaciones, encuentran que es costo-efectivo el tratamiento antiviral; 3/6 estudios que evalúan lamivudina frente a otros esquemas la encuentran como estrategia dominante, 3/5 encuentran a entecavir como estrategia dominante, 1/1 a tenofovir como dominante, 1/4 a interferón convencional como dominante y ninguno encuentra a adefovir ni interferón pegilado como estrategia dominante. Conclusiones. Consideramos que la evidencia disponible sugiere que brindar tratamiento antiviral para hepatitis B crónica sea una intervención costo-efectiva para muchos sistemas de salud, incluyendo el nuestro, con índicesvariables de costo-efectividad de acuerdo con los esquemas evaluados. Idealmente, se debe realizar evaluaciones económicas locales en este aspecto.

Objective. To revise the available evidence on the cost-effectiveness of antiviral regimens for treatment of chronic hepatitis B. Material and methods. We performed a systematic revision on MEDLINE, LILACS NICE and COCHRANE databases, searching for economic evaluations of antiviral regimens for treatment of chronic hepatitis B. We included original studies, systematic revisions and management guidelines including information on the cost-effectiveness of this treatment. We registered the characteristics and results of the retrieved documents. Results. We obtained 29 originalpapers, 4 revision articles and 4 management guidelines. Most of these publications have been done in the last 5 years. There was conflict of interest in 73 per cent of original articles, due to authors working for the pharmaceutical industry. 93 per cent of articles that evaluate the cost-effectiveness of giving treatment for chronic hepatitis B against management of its complications find that it is indeed cost-effective to give antiviral treatment. 3/6 studies that evaluate lamivudine against other drugs find it as a dominant strategy, 3/5 find entecavir as the dominant strategy, 1/1 find tenofovir dominant, » find conventional interferon as dominant and none of them find adefovir or pegylated interferon as dominant strategies. Conclusions. We consider that the available evidence suggests that to give antiviral treatment for chronic hepatitis B is a cost-effective intervention for many health systems, including ours. It has varying indexes of cost-effectiveness according to the evaluated regimens. Ideally , we should perform local economic evaluations in this issue.

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