Constanza Vargas is a Research Fellow at CHERE. She has a background in pharmaceutical science and a Master’s degree in Health Economics, from the University of Queensland. Prior to joining CHERE, Constanza worked as a research coordinator in the Health Technology Assessment Unit of the Clinical Research Centre at the Pontificia Universidad Catolica in Santiago, Chile. She has experience in the development and adaptations of economics evaluations to support decision making, teaching post graduate courses in fundamentals of health economics and economic evaluations, critical appraisal of clinical evidence and the writing of scientific articles. Since joining CHERE she has reviewed and conducted evaluations for Pharmaceutical Benefits Advisory Committee.
Vargas, C, Balmaceda, C, Rodríguez, F, Rojas, R, Giglio, A & Espinoza, MA 2019, 'Economic evaluation of sunitinib versus pazopanib and best supportive care for the treatment of metastatic renal cell carcinoma in Chile: cost-effectiveness analysis and a mixed treatment comparison', Expert Review of Pharmacoeconomics & Outcomes Research, vol. 19, no. 5, pp. 609-617.View/Download from: Publisher's site
Vargas Parada, CL, Bilbeny, N, Balmaceda, C, Rodriguez, MF, Zitko, P, Rojas, R, Eberhard, ME, Ahumada, M & Espinoza, M 2018, 'Costs and consequences of chronic pain due to musculoskeletal disorders from a health system perspective in Chile', Pain Reports, vol. 3, no. 5, pp. e656-e656.
Espinoza, MA & Vargas, C 2017, 'Evaluación de tecnologías sanitarias para la toma de decisiones y la rendición de cuentas: una urgente reflexión para el sistema de salud chileno [Evaluation of health technologies for decision making and accountability: an urgent reflection for the Chilean health system]', Value in Health Regional Issues, vol. 14, pp. 33-34.View/Download from: Publisher's site
En los últimos años hemos observado un creciente interés de los
sistemas de salud por implementar mejores procesos de decisión
de cobertura en salud, más transparentes, éticamente valorables
y anclados en evidencia científica. La Evaluación de Tecnologías
en Salud (ETESA) ha servido como un marco conceptual de
referencia para avanzar en este esfuerzo. Su perspectiva multidisciplinaria,
que incluye consideraciones médicas, económicas,
sociales, éticas y legales , ha hecho eco en los diversos actores
de un sistema de salud pues obliga a la inclusión de todas las
perspectivas dentro del proceso.
A partir de las experiencias desarrolladas en el mundo, es
posible identificar dos propósitos fundamentales en la implementación
de ETESA como política pública . El primero, y
probablemente el más reconocido, es dar soporte a la toma de
decisiones, la cual estaría fundamentado en los hallazgos de la
evidencia científica, y el valor que dicha sociedad le otorga a esa
evidencia. El segundo propósito, que a nuestro juicio es tan
importante como el primero, es la rendición de cuentas a la
sociedad. Esto quiere decir que toda la evidencia revisada, las
consideraciones puestas a discusión, las disputas y sus resoluciones,
y los argumentos finales que sustentan la decisión, se
revelan a la sociedad para su público escrutinio.
Vargas, C, Espinoza, MA, Giglio, A & Soza, A 2017, 'Estudio de impacto presupuestal de Daclatasvir asociado a Asunaprevir desde la perspectiva del sistema de salud público chileno', Value in Health Regional Issues, vol. 14, pp. 28-32.View/Download from: Publisher's site
© 2017 Objectives To assess the impact on the 2015 national health budget of incorporating Daclatasvir/Asunaprevir (DCV / ASV) for the treatment of Hepatitis C genotype 1b (HC1b) in Chile. Methods A Chilean HC1b patients cohort was modelled using local prevalence and incidence data. Two scenarios were built and compared, one were all patients receive Peginterferon/Ribavirin (PR) and another were all patients are treated with DCV/ASV. The analysis was conducted from the perspective of public health system of Chile assuming 100% reimbursement and a time horizon of 5 years. Costs associated with drug treatment, adverse events, other relevant resources and costs associated with disease complications were used. Results At a total DCV/ASV treatment price of USD $55,039, an additional of USD $65,6MM are required during the first year (prevalent cases) equivalent to 0.71% of the 2015 national health budget. From year 2 (incident cases), an additional of USD $12,3MM are needed (0.13% of the 2015 health budget). A price reduction of 33% (USD $36,693), requires an additional of USD $38,2MM the first year and USD $7,16MM from the second year (0.11% and 0.6% of the health budget). If the treatment price is reduced further (USD $18,347), an additional USD $10,9MM are required for the first year and USD $2,03MM from the second year (0.3% and 0.057% of the 2015 heath budget). Conclusion The impact on the health budget ranges between 0.3% and 0.71% the first year and decreases to less than 0.15% from the second year considering the price assessed price range.
Vargas Parada, C & Lennert Veerman, J 2016, 'Cost-Effectiveness Study of HPV Vaccination as a Primary Prevention Strategy for Anal Cancer in HIV-Positive Men in Chile', Value in Health Regional Issues, vol. 11, pp. 17-23.View/Download from: Publisher's site
© 2016 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Background: Most anal cancers are caused by the human papilloma virus (HPV) infection. The incidence is increasing, especially in high-risk individuals such as HIV-positive men. Evidence shows that the new quadrivalent HPV vaccine reduces the rates of anal intraepithelial neoplasia among men who have sex with men. Objective: To determine whether vaccinating against HPV-related anal cancer is cost-effective in HIV-positive men in Chile. Methods: A cost-effectiveness analysis was conducted by constructing a cohort multistate life-table-based Markov model in MS Excel in which the prevention of HPV infection was expected to influence the incidence of anal cancer in HIV-positive men. The comparator was the current practice of no systematic HPV prevention. Estimates of the efficacy of the vaccine were obtained from a substudy of a larger randomized controlled trial, incidence rates from the Chilean Population Cancer Registries, mortality rates from the National Institute of Statistics, and disease costs from a cost-effectiveness report. A public health care sector perspective was applied. The outcome was measured in averted disability-adjusted life-years. The incremental cost-effectiveness ratio was calculated considering a lifetime horizon for costs and health outcomes. Results: The estimated incremental cost-effectiveness ratio was US $138,269/ disability-adjusted life-year (95% confidence interval $95,936-$221,862). Assuming a threshold of 3 times the gross domestic product per capita, the intervention was not cost-effective. The outcome was sensitive to the vaccine price and vaccine efficacy. Conclusions: HPV vaccination in HIV-positive men from a Chilean public health care sector perspective is not cost-effective.
Vargas, C, Giglio, A, Soza, A & Espinoza, MA 2015, 'Estudio De Impacto Presupuestal De Daclatasvir Asociado A Asunaprevir Desde La Perspectiva Del Sistema De Salud Publico Chileno.', Value in health : the journal of the International Society for Pharmacoeconomics and Outcomes Research, vol. 18, no. 7, p. A866.View/Download from: Publisher's site
Vargas, CL, Espinoza, MA, Giglio, A & Soza, A 2015, 'Cost effectiveness of daclatasvir/asunaprevir versus peginterferon/ribavirin and protease inhibitors for the treatment of hepatitis c genotype 1b Naïve patients in Chile', PLoS ONE, vol. 10, no. 11.View/Download from: Publisher's site
© 2015 Vargas et al. Introduction: Daclatasvir and Asunaprevir (DCV/ASV) have recently been approved for the treatment of chronic hepatitis C virus infection. In association, they are more effective and safer than previous available treatments, but more expensive. It is unclear if paying for the additional costs is an efficient strategy considering limited resources. Methods: A Markov model was built to estimate the expected costs in Chilean pesos (CL$) and converted to US dollars (US$) and benefits in quality adjusted life years (QALYs) in a hypothetic cohort of naive patients receiving DCV/ASV compared to protease inhibitors (PIs) and Peginterferon plus Ribavirin (PR). Efficacy was obtained from a mixed-treatment comparison study and costs were estimated from local sources. Utilities were obtained applying the EQ-5D survey to local patients and then valued with the Chilean tariff. A time horizon of 46 years and a discount rate of 3% for costs and outcomes was considered. The ICERs were estimated for a range of DCV/ASV prices. Deterministic and probabilistic sensitivity analyses were performed. Results: PIs were extendedly dominated by DCV/ASV. The ICER of DCV/ASV compared to PR was US$ 16,635/QALY at a total treatment price of US$ 77,419; US$11,581 /QALY at a price of US$ 58,065; US$ 6,375/QALY at a price of US$ 38,710; and US$ 1,364 /QALY at a price of US$ 19,355. The probability of cost-effectiveness at a price of US$ 38,710 was 91.6%while there is a 21.43% probability that DCV/ASV dominates PR if the total treatment price was US$ 19,355. Although the results are sensitive to certain parameters, the ICER did not increase above the suggested threshold of 1 GDP per capita. Conclusions: DCV/ASV can be considered cost-effective at any price of the range studied. These results provide decision makers useful information about the value of incorporating these drugs into the public Chilean healthcare system.