Anchoring bias in face-to-face Time-Trade-Off valuations of health states / Sesgo de anclaje en valoraciones de estados de salud por Time Trade-Off

ABSTRACT Objective To test whether anchoring (a cognitive bias) occurs during face-to-face interviews to value health states by Time-Trade-Off. Methods 147 Colombian subjects (111 males, 36 females) valued five EQ-5D health states better than death during a face-to-face interview. Subjects were randomly assigned to two different starting points. Results Shapiro-Wilk test discarded normality, while non-parametric tests, including Kolmogorov-Smirnov and Wilcoxon-Mann-Whitney, showed that anchoring was significant in four out of five health states. A higher starting point increased the elicited value by 15 %-188 %. The size of the anchoring effect was not uniform among health states. Conclusion Anchoring effects may bias face-to-face Time Trade-Off valuations. The size of the anchoring effect is relevant enough for health policy.(AU)

RESUMEN Objetivos Comprobar si se presenta anclaje (un sesgo cognitivo) en las valoraciones de estados de salud por Time-Trade-Off realizadas en entrevistas en persona. Métodos 147 sujetos colombianos (111 hombres, 36 mujeres) valoraron five estados de salud EQ-5D mejores que la muerte en una entrevista personal. Los sujetos se asignaron aleatoriamente a dos puntos de partida distintos. Resultados El test de Shapiro-Wilk descartó normalidad de las distribuciones. Las pruebas no paramétricas de Kolmogorov-Smirnov y Wilconson-Mann-Whitney mostraron que el anclaje era significativo en cuatro de los cinco estados de salud. Un punto de partida más alto aumentaba el valor obtenido en un 15 %-188 %. El tamaño del anclaje no era uniforme en los distintos estados de salud. Conclusiones El anclaje puede sesgar las valoraciones por Time Trade-Off realizadas en entrevistas. El efecto es lo suficientemente alto como para hacerlo relevante en términos de política.(AU)

Costo efectividad de las pruebas para estratificar riesgo en el tratamiento de la leucemia mieloide aguda (LMA) en población pediátrica / Cost-effectiveness of risk stratification tests for the treatment of acute myeloid leukemia in pediatric patients

RESUMEN Objetivo Estimar la razón de costo-efectividad de las pruebas para estratificación del riesgo en pacientes pediátricos con Leucemia Mieloide Aguda (LMA). Métodos Se construyó un árbol de decisión con años de vida ganados como medida de efectividad. Los costos fueron estimados desde la perspectiva del sistema de salud colombiano. En los costos de la estratificación se incluyeron los costos del tratamiento consecuente con ella. Los precios de medicamentos fueron tomados del SISMED 2008 y el valor monetario de los procedimientos se extrajo del manual tarifario del ISS 2001 adicionando el 30 %. Todos los costos se expresaron en pesos colombianos del 2010 y el producto interno per-cápita de ese año fue empleado como umbral de costo efectividad. Se condujeron análisis de sensibilidad univariados y probabilísticos. Resultados La razón de costo-efectividad incremental de las pruebas de estratificación a todos los pacientes, fue de $8 559 944. Los resultados son sensibles a las probabilidades de recaída, supervivencia al trasplante y efectos secundarios. Conclusión Las pruebas para estratificación del riesgo en LMA son costo-efectivas dentro del sistema de salud colombiano.(AU)

ABSTRACT Objective To estimate the cost-effectiveness of risk-stratification tests for the treatment of acute myeloid leukemia (AML) in pediatric patients. Methods A decision-tree model was built using Life Years Gained as a measure of effectiveness. Costs were estimated considering the perspective of the Colombian health system. Stratification costs included treatment costs based on said stratification. Drug prices were taken from SISMED (Drug Price Information System) 2008 and the monetary value of the procedures was extracted from the ISS 2001 rate manual, plus 30%. All costs were expressed in Colombian pesos for 2010 and the gross domestic product per capita of the same year was used as a cost-effective threshold. Univariate and probabilistic sensitivity analyzes were performed. Results Risk stratification tests have an incremental cost-effectiveness ratio of COP 8,559,944. These results are sensitive to changes in probabilities of relapse, transplant survival and side effects. Conclusion Risk stratification tests for AML treatment in pediatric patients are cost-effective in the context of the Colombian health care system.(AU)

[Cost-effectiveness of risk stratification tests for the treatment of acute myeloid leukemia in pediatric patients]. / Costo efectividad de las pruebas para estratificar riesgo en el tratamiento de la leucemia mieloide aguda (LMA) en población pediátrica.

OBJECTIVE: To estimate the cost-effectiveness of risk-stratification tests for the treatment of acute myeloid leukemia (AML) in pediatric patients. METHODS: A decision-tree model was built using Life Years Gained as a measure of effectiveness. Costs were estimated considering the perspective of the Colombian health system. Stratification costs included treatment costs based on said stratification. Drug prices were taken from SISMED (Drug Price Information System) 2008 and the monetary value of the procedures was extracted from the ISS 2001 rate manual, plus 30%. All costs were expressed in Colombian pesos for 2010 and the gross domestic product per capita of the same year was used as a cost-effective threshold. Univariate and probabilistic sensitivity analyzes were performed. RESULTS: Risk stratification tests have an incremental cost-effectiveness ratio of COP 8,559,944. These results are sensitive to changes in probabilities of relapse, transplant survival and side effects. CONCLUSION: Risk stratification tests for AML treatment in pediatric patients are cost-effective in the context of the Colombian health care system.

OBJETIVO: Estimar la razón de costo-efectividad de las pruebas para estratificación del riesgo en pacientes pediátricos con Leucemia Mieloide Aguda (LMA). MÉTODOS: Se construyó un árbol de decisión con años de vida ganados como medida de efectividad. Los costos fueron estimados desde la perspectiva del sistema de salud colombiano. En los costos de la estratificación se incluyeron los costos del tratamiento consecuente con ella. Los precios de medicamentos fueron tomados del SISMED 2008 y el valor monetario de los procedimientos se extrajo del manual tarifario del ISS 2001 adicionando el 30 %. Todos los costos se expresaron en pesos colombianos del 2010 y el producto interno per-cápita de ese año fue empleado como umbral de costo efectividad. Se condujeron análisis de sensibilidad univariados y probabilísticos. RESULTADOS: La razón de costo-efectividad incremental de las pruebas de estratificación a todos los pacientes, fue de $8 559 944. Los resultados son sensibles a las probabilidades de recaída, supervivencia al trasplante y efectos secundarios. CONCLUSIÓN: Las pruebas para estratificación del riesgo en LMA son costo-efectivas dentro del sistema de salud colombiano.

Anchoring bias in face-to-face Time-Trade-Off valuations of health states.

OBJECTIVE: To test whether anchoring (a cognitive bias) occurs during face-to-face interviews to value health states by Time-Trade-Off. METHODS: 147 Colombian subjects (111 males, 36 females) valued five EQ-5D health states better than death during a face-to-face interview. Subjects were randomly assigned to two different starting points. RESULTS: Shapiro-Wilk test discarded normality, while non-parametric tests, including Kolmogorov-Smirnov and Wilcoxon-Mann-Whitney, showed that anchoring was significant in four out of five health states. A higher starting point increased the elicited value by 15 %-188 %. The size of the anchoring effect was not uniform among health states. CONCLUSION: Anchoring effects may bias face-to-face Time Trade-Off valuations. The size of the anchoring effect is relevant enough for health policy.

Costo efectividad del suplemento de calcio para reducir la mortalidad materna asociada a preeclampsia en Colombia / Cost effectiveness of calcium supplement in reducing preeclampsia-related maternal mortality in Colombia

Objetivo Estimar el costo-efectividad de la administración de calcio (1 200 mg diarios) a partir de la semana 14 de gestación a todas las gestantes, comparada con no administrarlo, para reducir la incidencia de preeclampsia. Métodos Se construyó un árbol de decisión en TreeAge® con desenlace en años de vida ganados (AVG). Los costos se incluyeron desde la perspectiva del sistema de salud colombiano, en pesos (COP) de 2014. La tasa de descuento fue de 0%. Se realizaron análisis de sensibilidad univariados y probabilísticos para costos y efectividad. Resultados El suplemento de calcio es una alternativa dominante frente a la no intervención. Si la incidencia de preeclampsia es menor a 51,7 por 1 000 gestantes o el costo por tableta de calcio de 600 mg es mayor a COP$ 507,85, el suplemento de calcio deja de ser una alternativa costo-efectiva en Colombia para un umbral de 3 veces el PIB per cápita de 2013 (COP$ 45 026 379) por AVG. Conclusiones La administración de calcio a todas las gestantes a partir de la semana 14 de gestación es una alternativa dominante frente a la no intervención, que permite ganar 200 años de vida, al tiempo que disminuye costos del orden de COP$ 5 933 millones por 100 000 gestantes.(AU)

Objectives To estimate the cost-effectiveness of administering calcium (1200 mg per day) starting in week 14 of pregnancy to all pregnant women compared to not supplying it to reduce the incidence of preeclampsia. Methods A decision tree was built in TreeAge® with outcome measured in life years gained (LYG) associated with the reduction in maternal deaths. Costs were included from the perspective of the health system in Colombia and expressed in Colombian pesos in 2014 (COP). The discount rate was 0 %. We performed sensitivity univariate and probabilistic analyses for costs and effectiveness. Results Compared to no intervention, calcium supplement is a dominant alternative. If the incidence of preeclampsia is lower than 51.7 per 1 000 pregnant women or the cost per tablet of calcium of 600 mg is greater than COP $507.85, calcium supplement is no longer a cost-effective alternative in Colombia for a threshold of COP $ 45 026 379 (3 times the Colombian per capita GDP of 2013 per LYG). Conclusions Supplying calcium to all pregnant women from week 14 of gestation is a dominant alternative compared to no intervention, which saves 200 LYG, while it decreases costs to the order of COP$5 933 million per 100.000 pregnant women.(AU)

[Cost effectiveness of calcium supplement in reducing preeclampsia-related maternal mortality in Colombia]. / Costo efectividad del suplemento de calcio para reducir la mortalidad materna asociada a preeclampsia en Colombia.

Objectives To estimate the cost-effectiveness of administering calcium (1200 mg per day) starting in week 14 of pregnancy to all pregnant women compared to not supplying it to reduce the incidence of preeclampsia. Methods A decision tree was built in TreeAge® with outcome measured in life years gained (LYG) associated with the reduction in maternal deaths. Costs were included from the perspective of the health system in Colombia and expressed in Colombian pesos in 2014 (COP). The discount rate was 0 %. We performed sensitivity univariate and probabilistic analyses for costs and effectiveness. Results Compared to no intervention, calcium supplement is a dominant alternative. If the incidence of preeclampsia is lower than 51.7 per 1 000 pregnant women or the cost per tablet of calcium of 600 mg is greater than COP $507.85, calcium supplement is no longer a cost-effective alternative in Colombia for a threshold of COP $ 45 026 379 (3 times the Colombian per capita GDP of 2013 per LYG). Conclusions Supplying calcium to all pregnant women from week 14 of gestation is a dominant alternative compared to no intervention, which saves 200 LYG, while it decreases costs to the order of COP$5 933 million per 100.000 pregnant women.

The cost-effectiveness of open or thoracoscopic thymectomy compared to medical treatment in managing Myasthenia gravis without thymomas.

OBJECTIVE: Assessing the cost-effectiveness of open or thoracoscopic thymectomy compared to medical therapy in managing myasthenia gravis not associated with thymoma. METHODS: A Markov model was designed for evaluating three strategies' cost-effectiveness. Transition probabilities were taken from the pertinent literature; the costs were estimated from official tariff manuals. Incremental cost-effectiveness ratios were estimated and probabilistic and deterministic sensitivity analysis was used for clinical variables, costs and the model's assumptions. RESULTS: Thoracoscopic thymectomy was the most effective and least costly strategy and dominated the other two alternatives. The cost per life year gained was Col $ 1 129 531 without discount and Col $ 805 179 with discount. Univariate sensitivity analysis showed that the main variables affecting the results were the effects' discount rate, the cost of a myasthenic crisis and the probability of complete remission. Thoracoscopy thymectomy was the most cost-effective strategy for different thresholds of willingness to pay in probabilistic analysis. CONCLUSIONS: Thoracoscopic thymectomy is a cost-effective strategy in the treatment of MG without thymoma.

Costo-efectividad del uso de resonancia magnética y radiografía convencional en pacientes con pie diabético / The cost-effectiveness of using magnetic resonance plus conventional radiography in diabetic-foot patients

Objetivo Analizar, desde la perspectiva del pagador, la costo efectividad de la adición de resonancia magnética a la radiografía convencional en pacientes con pie diabético y signos de infección, en Colombia. Métodos Mediante un modelo de Markov, se identificó la relación de costo-efectividad de la adición de resonancia magnética a la radiografía convencional en pacientes con pie diabético y signos de infección en Colombia. La perspectiva es la del pagador. Los costos se valoraron en pesos colombianos de 2008, la efectividad se mide en años de vida ajustados por discapacidad, AVAD y el umbral de costo efectividad fue el PIB per cápita colombiano de 2008, $ 10 761 691. Resultados Usar resonancia magnética además de radiografía convencional en estos pacientes tiene un indicador de costo efectividad incremental por AVAD de $ 1 532 778 y de $ 1 741 311 sin y con descuento respectivamente. Los resultados son robustos a pruebas de sensibilidad. Conclusiones La resonancia magnética unida a la radiografía convencional en la evaluación del pie diabético con signos de infección es costo-efectiva para Colombia.

Objective Performing a cost-effectiveness analysis of adding magnetic resonance to conventional radiography in patients suffering from diabetic foot and signs of infection from the payer's point of view. Material and methods The cost effectiveness (from the payer's point of view) of conventional radiography plus magnetic resonance was calculated for patients having diabetic foot and signs of infection by means of a Markov model. Costs were measured in 2008 Colombian pesos and effectiveness in terms of disability adjusted life years (DALY). The cost-effectiveness threshold was the Colombian 2008 per capita GDP, $ 10,761,691. Results Using magnetic resonance in addition to conventional radiography in this population had a $ 1,532,778 and $ 1,741,311 incremental cost-effectiveness ratio, without and with discount, respectively; the results were robust to sensitivity analysis. Conclusions Using magnetic resonance in addition to conventional radiography in patients suffering from diabetic foot and signs of infection was cost-effective for Colombia.

[The cost-effectiveness of using magnetic resonance plus conventional radiography in diabetic-foot patients]. / Costo-efectividad del uso de resonancia magnética y radiografía convencional en pacientes con pie diabético.

OBJECTIVE: Performing a cost-effectiveness analysis of adding magnetic resonance to conventional radiography in patients suffering from diabetic foot and signs of infection from the payer's point of view. MATERIAL AND METHODS: The cost effectiveness (from the payer's point of view) of conventional radiography plus magnetic resonance was calculated for patients having diabetic foot and signs of infection by means of a Markov model. Costs were measured in 2008 Colombian pesos and effectiveness in terms of disability adjusted life years (DALY). The cost-effectiveness threshold was the Colombian 2008 per capita GDP, $ 10,761,691. RESULTS: Using magnetic resonance in addition to conventional radiography in this population had a $ 1,532,778 and $ 1,741,311 incremental cost-effectiveness ratio, without and with discount, respectively; the results were robust to sensitivity analysis. CONCLUSIONS: Using magnetic resonance in addition to conventional radiography in patients suffering from diabetic foot and signs of infection was cost-effective for Colombia.

The cost-effectiveness of open or thoracoscopic thymectomy compared to medical treatment in managing Myasthenia gravis without thymomas / Costo efectividad de timectomía abierta y toracoscópica frente al tratamiento médico, en el manejo de Miastenia gravis sin timoma

Objective Assessing the cost-effectiveness of open or thoracoscopic thymectomy compared to medical therapy in managing myasthenia gravis not associated with thymoma. Methods A Markov model was designed for evaluating three strategies' cost-effectiveness. Transition probabilities were taken from the pertinent literature; the costs were estimated from official tariff manuals. Incremental cost-effectiveness ratios were estimated and probabilistic and deterministic sensitivity analysis was used for clinical variables, costs and the model's assumptions. Results Thoracoscopic thymectomy was the most effective and least costly strategy and dominated the other two alternatives. The cost per life year gained was Col § 1 129 531 without discount and Col § 805 179 with discount. Univariate sensitivity analysis showed that the main variables affecting the results were the effects' discount rate, the cost of a myasthenic crisis and the probability of complete remission. Thoracoscopy thymectomy was the most cost-effective strategy for different thresholds of willingness to pay in probabilistic analysis. Conclusions Thoracoscopic thymectomy is a cost-effective strategy in the treatment of MG without thymoma.

Objetivo Evaluar la costo efectividad de las timectomía abierta y toracoscópica frente a la terapia mé,dica en el manejo de miastenia gravis sin timoma. Mé,todo Se construyó un modelo de Markov para evaluar la costo efectividad de las 3 estrategias. Las probabilidades de transición se obtuvieron de la literatura. Los costos se estimaron a partir de las tarifas oficiales. Se calculó la costo-efectividad incremental. Se realizaron análisis de sensibilidad probabilísticos y determinísticos para las variables clínicas, los costos supuestos del modelo. Resultados La timectomía toracoscópica es la estrategia más efectiva y menos costosa, y domina a las otras dos alternativas. El costo por año de vida ganado fue de § 1 129 531 y § 805 179 pesos colombianos, con y sin descuento. El análisis de sensibilidad univariado mostró que las principales variables que afectan los resultados son la tasa de descuento, el costo de una crisis miasté,nica y la probabilidad de remisión completa. En el análisis de sensibilidad probabilístico, la timectomía toracoscópica es la estrategia costo-efectiva para los diferentes umbrales de disponibilidad a pagar. Conclusiones La timectomía toracoscópica es una estrategia costo-efectiva en el tratamiento de miastenia gravis sin timoma.

Evaluación económica de la vacuna contra la influenza aplicada al personal de salud que atiende pacientes oncológicos hospitalizados / Economic evaluation of influenza vaccine applied to health personnel attending hospitalised oncological patients

Objetivos Analizar, desde la perspectiva del pagador, el costo efectividad de la vacunación contra influenza al personal de salud que tiene contacto estrecho con los pacientes oncológicos hospitalizados en Colombia. Métodos Mediante un árbol de decisión, se identificó la relación de costo-efectividad de la aplicación de esta vacuna al personal de salud que tiene contacto estrecho con los pacientes oncológicos hospitalizados. La perspectiva es la del pagador. Los costos se valoraron en unidades monetarias y la efectividad se mide por la reducción en días de hospitalización de pacientes oncológicos como resultado de la disminución en las probabilidades de contraer el virus por la vacunación al personal de salud. Resultados Vacunar contra la influenza al personal de salud que tiene contacto estrecho con los pacientes oncológicos hace que, al ahorrar un día de estancia hospitalaria, simultáneamente se ahorren $ 2 978 000 (US$ 1 324). Conclusiones Vacunar contra la influenza al personal de salud que tiene contacto estrecho con los pacientes oncológicos es costo efectivo para una probabilidad de contagio del personal de salud que no ha sido vacunado mayor o igual a 0,02.

Objective Performing a cost-effectiveness evaluation of influenza vaccine for health workers coming into close contact with oncological patients from the payer's point of view. Methods As no evidence was found for influenza vaccine effectiveness in oncological patients, the cost-effectiveness of applying the vaccine to health workers coming into close contact with oncological patients was calculated by means of a decision tree; the payer's point of view was adopted. Costs were evaluated in monetary units and effectiveness was measured by the reduction in length of hospital stay for cancer patients as a result of lesser probability of catching the disease because of vaccinating the health workers. Results Vaccinating health workers coming into close contact with cancer patients led to savings of $2 978 000 (US$1 324) per day of stay saved. Conclusions Vaccinating health workers coming into close contact with cancer patients proved cost-effective, returning health worker contagion probability higher than or equal to 0.02.

[Economic evaluation of influenza vaccine applied to health personnel attending hospitalised oncological patients]. / Evaluación económica de la vacuna contra la influenza aplicada al personal de salud que atiende pacientes oncológicos hospitalizados.

OBJECTIVE: Performing a cost-effectiveness evaluation of influenza vaccine for health workers coming into close contact with oncological patients from the payer's point of view. METHODS: As no evidence was found for influenza vaccine effectiveness in oncological patients, the cost-effectiveness of applying the vaccine to health workers coming into close contact with oncological patients was calculated by means of a decision tree; the payer's point of view was adopted. Costs were evaluated in monetary units and effectiveness was measured by the reduction in length of hospital stay for cancer patients as a result of lesser probability of catching the disease because of vaccinating the health workers. RESULTS: Vaccinating health workers coming into close contact with cancer patients led to savings of $2,978,000 (US$1,324) per day of stay saved. CONCLUSIONS: Vaccinating health workers coming into close contact with cancer patients proved cost-effective, returning health worker contagion probability higher than or equal to 0.02.

[Economic impact of pneumococcal vaccine on oncological patients]. / Impacto Económico de la Vacuna contra el Neumococo en Pacientes Oncológicos.

OBJECTIVE: An economic evaluation of an anti-S pneumoniae vaccine for oncological patients in Colombia. METHODS: As there is no evidence of vaccine effectiveness for this kind of patient, the cost of a vaccination programme for oncological patients was calculated during its first six years and the opportunity cost was estimated for early cancer detection alternatives. RESULTS: An anti-S. pneumoniae vaccination programme for oncological patients would cost around $31,000,000,000 (Colombian pesos in 2006, i.e. nearly US$12,400,000) during its first years. Alternative programs could be developed with this amount, such as 170,000 colonoscopies or early HPV detection, 500,000 mammographies, or more than 3,800,000 cytologies. CONCLUSIONS: Given the scarcity of resources, it would be better (from an economic point of view) to devote this amount to programmes whose effectiveness has been proven, such as early cancer detection or vaccinating healthy children.

Impacto Económico de la Vacuna contra el Neumococo en Pacientes Oncológicos / Economic impact of neumococcal vaccine on oncological patients

Objetivos: Evaluar económicamente la vacuna contra S pneumoniae en pacientes oncológicos para Colombia. Métodos: Dado que la efectividad de la vacuna en este tipo de pacientes no está comprobada, se calculó el costo de los primeros seis años de un programa de vacunación para pacientes oncológicos y se estimó el costo de oportunidad con alternativas de detección temprana de cáncer. Resultados: Un programa de vacunación de pacientes oncológicos contra S pneumoniae costaría en sus primeros seis años cerca de treinta y un mil millones de pesos constantes de 2006. Con estos recursos se podrían realizar aproximadamente 170 000 colonoscopias o pruebas de detección temprana de VPH, 500 000 mamografías o más de 3 800 000 citologías. Conclusiones: Dada la escasez de recursos, es preferible económicamente destinar estas cifras a adelantar programas cuya efectividad esté comprobada, ya sea para detección temprana de cáncer o para vacunación de niños sanos.

Objective: An economic evaluation of an anti-S pneumoniae vaccine for oncological patients in Colombia. Methods: As there is no evidence of vaccine effectiveness for this kind of patient, the cost of a vaccination programme for oncological patients was calculated during its first six years and the opportunity cost was estimated for early cancer detection alternatives. Results: An anti-S. pneumoniae vaccination programme for oncological patients would cost around $31 000 000 000 (Colombian pesos in 2006, i.e. nearly US$12 400 000) during its first years. Alternative programs could be developed with this amount, such as 170 000 colonoscopies or early HPV detection, 500 000 mammographies, or more than 3 800 000 cytologies. Conclusions: Given the scarcity of resources, it would be better (from an economic point of view) to devote this amount to programmes whose effectiveness has been proven, such as early cancer detection or vaccinating healthy children.