[Transversal Health Research Networks, a strategy for translational medicine]. / Redes Transversales de Investigación en Salud: estrategia para la medicina traslacional.

Translational research, in its regulatory function as a current policy for the research activities being performed at the Mexican Institute for Social Security (Instituto Mexicano del Seguro Social: IMSS), demands a collaborative work among people involved in the generation of knowledge and in those who consume such knowledge. Being an organization who has among its major objectives for almost 80 years the health care of Mexican population, the Institute has an important human capital represented by its physician leaders, researchers and directors, who, by working closely together, will be able to find a better respond to the health care needs of the Mexican population. Through collaborative groups, transversal research networks oriented to the priority health problems of Mexican people are being organized as a strategy whose purpose is making research more efficient and ensuring rapidly applicable results, in order to improve the quality of health care services offered by the Institute, whose commitment is primarily to Mexican society, although the results of this strategy could also be shown to the world, considering that the Institute is one of the largest public health service organizations, at least in Latin America, and its results could be a benchmark for the region. Collaborative work in research networks began more than 15 years ago at IMSS, but today it is being consolidated and its objectives are being reoriented, aligning them with both national policies and those of the Institute itself.

La investigación traslacional, como la política vigente de las actividades de investigación que se realizan en el Instituto Mexicano del Seguro Social (IMSS), requiere del trabajo colaborativo de los actores involucrados en la generación del conocimiento y de los que consumen el conocimiento. Al ser una organización que tiene como uno de sus principales objetivos la atención a la salud de la población mexicana desde hace casi 80 años, el Instituto cuenta en sus filas con un importante capital humano, representado por sus líderes médicos, investigadores y directivos, que, al trabajar en conjunto, podrán encontrar mejores respuestas a las necesidades de salud de la población mexicana. La organización por medio de grupos colaborativos en redes transversales de investigación orientadas a los problemas prioritarios de salud de los mexicanos es una estrategia que busca que la investigación sea más eficiente y que sus resultados sean prontamente aplicables, a fin de mejorar la calidad de la atención de los servicios de salud que oferta el Instituto, compromiso que se tiene primero con la sociedad mexicana, pero además se puede mostrar al mundo, ya que el Instituto es una de las más grandes organizaciones de servicios de salud pública, al menos en Latinoamérica, por lo que sus resultados pueden ser un referente para la región. El trabajo colaborativo en redes de investigación inició hace más de 15 años en el IMSS, pero hasta el día de hoy se fortalece y se reorientan sus objetivos, los cuales se alinean a las políticas nacionales y a las propias del Instituto.

Association Analysis Between the Functional Single Nucleotide Variants in miR-146a, miR-196a-2, miR-499a, and miR-612 With Acute Lymphoblastic Leukemia.

BACKGROUND: Acute lymphoblastic leukemia (ALL) is characterized by an abnormal proliferation of immature lymphocytes, in whose development involves both environmental and genetic factors. It is well known that single nucleotide polymorphisms (SNPs) in coding and noncoding genes contribute to the susceptibility to ALL. This study aims to determine whether SNPs in miR-146a, miR-196a-2, miR-499a, and miR-612 genes are associated with the risk to ALL in pediatric Mexican population. METHODS: A multicenter case-control study was carried out including patients with de novo diagnosis of ALL and healthy subjects as control group. The DNA samples were obtained from saliva and peripheral blood, and the genotyping of rs2910164, rs12803915, rs11614913, and rs3746444 was performed using the 5'exonuclease technique. Gene-gene interaction was evaluated by the multifactor dimensionality reduction (MDR) software. RESULTS: miR-499a rs3746444 showed significant differences among cases and controls. The rs3746444G allele was found as a risk factor to ALL (OR, 1.6 [95% CI, 1.05-2.5]; p = 0.028). The homozygous GG genotype of rs3746444 confers higher risk to ALL than the AA genotype (OR, 5.3 [95% CI, 1.23-23.4]; p = 0.01). Moreover, GG genotype highly increases the risk to ALL in male group (OR, 17.6 [95% CI, 1.04-298.9]; p = 0.00393). In addition, an association in a gender-dependent manner among SNPs located in miR-146a and miR-196a-2 genes and ALL susceptibility was found. CONCLUSION: Our findings suggest that SNP located in miR-499a, miR-146a, and miR-196a-2 genes confer risk to ALL in Mexican children. Experimental analysis to decipher the role of these SNPs in human hematopoiesis could improve our understanding of the molecular mechanism underlying the development of ALL.

Genotype-Environment Interaction Analysis of NQO1, CYP2E1, and NAT2 Polymorphisms and the Risk of Childhood Acute Lymphoblastic Leukemia: A Report From the Mexican Interinstitutional Group for the Identification of the Causes of Childhood Leukemia.

Background: Acute lymphoblastic leukemia (ALL) is the main type of cancer in children. In Mexico and other Hispanic populations, the incidence of this neoplasm is one of the highest reported worldwide. Functional polymorphisms of various enzymes involved in the metabolism of xenobiotics have been associated with an increased risk of developing ALL, and the risk is different by ethnicity. The aims of the present study were to identify whether NQO1, CYP2E1, and NAT2 polymorphisms or some genotype-environmental interactions were associated with ALL risk in Mexican children. Methods: We conducted a case-control study including 478 pediatric patients diagnosed with ALL and 284 controls (children without leukemia). Ancestry composition of a subset of cases and controls was assessed using 32 ancestry informative markers. Genetic-environmental interactions for the exposure to hydrocarbons were assessed by logistic regression analysis. Results: The polymorphisms rs1801280 (OR 1.54, 95% CI 1.21-1.93), rs1799929 (OR 1.96, 95% CI 1.55-2.49), and rs1208 (OR 1.44, 95% CI 1.14-1.81) were found to increase the risk of ALL; being the risks higher under a recessive model (OR 2.20, 95% CI 1.30-1.71, OR 3.87, 95% CI 2.20-6.80, and OR 2.26, 95% CI 1.32-3.87, respectively). Gene-environment interaction analysis showed that NAT2 rs1799929 TT genotype confers high risk to ALL under exposure to fertilizers, insecticides, hydrocarbon derivatives, and parental tobacco smoking. No associations among NQO1, CYP2E1, and ALL were observed. Conclusion: Our study provides evidence for the association between NAT2 polymorphisms/gene-environment interactions, and the risk of childhood ALL in Mexican children.

Análisis de coste-efectividad en el tratamiento farmacológico del síndrome de fibromialgia en México / Cost-effectiveness analysis of pharmacologic treatment of fibromyalgia in Mexico

Objetivo. Identificar desde la perspectiva del proveedor de servicios de salud pública en México el tratamiento más coste-efectivo para pacientes con síndrome de fibromialgia (SFM). Material y métodos. Mediante un modelo de Markov con 3 estados de salud, definidos por la intensidad del dolor (ausencia o presencia de dolor leve; moderado o severo), en ciclos de 3 meses, se estimaron los costes y las efectividades de amitriptilina (50mg/día), fluoxetina (80mg/día), duloxetina (120mg/día), gabapentina (900mg/día), pregabalina (450mg/día), tramadol/acetaminofén (150mg/1300mg/día) y amitriptilina/fluoxetina (50mg/80mg/día) en el tratamiento del SFM. El resultado clínico de interés fue el porcentaje de control del dolor al año de tratamiento. Las probabilidades asignadas al modelo se obtuvieron de la literatura publicada. Los costes médicos directos del tratamiento SFM se calcularon a través bases de datos del Instituto Mexicano del Seguro Social (IMSS) en 2006 y se expresaron en pesos mexicanos de 2010. El análisis de sensibilidad fue probabilístico. Resultados. El mejor control del dolor se obtiene con el uso de pregabalina (44,8%), seguido de gabapentina (38,1%) y duloxetina (34,2%). El tratamiento con menor coste, fue con amitriptilina ($ 9.047,01), seguido de fluoxetina ($ 10.183,89) y amitriptilina/fluoxetina ($ 10.866,01). Al comparar pregabalina vs amitriptilina, el coste anual adicional por paciente con control del dolor se encuentra entre $ 50.000 y $ 75.000 y resulta ser coste-efectivo entre el 70 y el 80% de los casos. Conclusiones. Entre las alternativas de tratamiento para el SFM, pregabalina alcanza el mejor control del dolor y es coste-efectiva hasta en el 80% de los pacientes del sistema de salud público en México (AU)

Objective. To identify, from the Mexican Public Health System perspective, which would be the most cost-effective treatment for patients with Fibromyalgia (FM). Material and methods. A Markov model including three health states, divided by pain intensity (absence or presence of mild, moderate or severe pain) and considering three-month cycles; costs and effectiveness were estimated for amitriptyline (50mg/day), fluoxetine (80mg/day), duloxetine (120mg/day), gabapentin (900mg/day), pregabalin (450mg/day), tramadol/acetaminophen (150mg/1300mg/día) and amitriptyline/fluoxetine (50mg/80mg/día) for the treatment of FM. The clinical outcome considered was the annual rate of pain control. Probabilities assigned to the model were collected from published literature. Direct medical costs for FM treatment were retrieved from the 2006 data of the Mexican Institute of Social Security (IMSS) databases and were expressed in 2010 Mexican Pesos. Probabilistic Sensitivity Analyses were conducted. Results. The best pain control rate was obtained with pregabalin (44.8%), followed by gabapentin (38.1%) and duloxetine (34.2%). The lowest treatment costs was for amitriptyline ($ 9047.01), followed by fluoxetine ($ 10,183.89) and amitriptyline/fluoxetine ($ 10,866.01). By comparing pregabalin vs amitriptyline, additional annual cost per patient for pain control would be around $ 50.000 and $ 75.000 and would result cost-effective in 70% and 80% of all cases. Conclusions. Among all treatment options for FM, pregabalin achieved the highest pain control and was cost-effective in 80% of patients of the Mexican Public Health System (AU)

Direct medical costs of treating Mexican children under 2 years of age with respiratory syncytial virus

Background. Respiratory syncytial virus (RSV) is the most frequent etiologic agent causing lower respiratory tract infection in children <2 years of age. Between 0.5 and 3% of patients will require hospitalization. The aim of this study was to estimate the direct medical cost of treating children <2 years old with suspicion of RSV at the Instituto Mexicano del Seguro Social (IMSS). Methods. Direct medical costs were estimated from an institutional perspective. Medical records were reviewed from patients <2 years of age who attended emergency services in second-level hospitals including subjects who required hospitalization. Estimated costs were obtained with the microcosting technique using the institutional costs from IMSS (year 2010). Costs were reported in USD (year 2011). Results. When analyzing total medical costs, outpatient management yielded a cost of $230.0 ± $10.30 U.S. dollars (USD), whereas hospitalized patients exhibited an average cost of $8,313.20 ± $595.30 USD. The main components of outpatient management costs were emergency visits, specialist consultations and diagnostic testing (41.6%, 32.7% and 10.7% of the total cost, respectively). In the case of hospitalized patients, intensive care unit cost (89.3%) and overall hospitalization cost (6.5%) represented 95.7% of the total cost. Conclusions. RSV is a disease that represents a significant economic burden for health care institutions, although most patients are treated on an outpatient basis.

Cost-effectiveness analysis of pharmacologic treatment of fibromyalgia in Mexico.

OBJECTIVE: To identify, from the Mexican Public Health System perspective, which would be the most cost-effective treatment for patients with Fibromyalgia (FM). MATERIAL AND METHODS: A Markov model including three health states, divided by pain intensity (absence or presence of mild, moderate or severe pain) and considering three-month cycles; costs and effectiveness were estimated for amitriptyline (50mg/day), fluoxetine (80 mg/day), duloxetine (120 mg/day), gabapentin (900 mg/day), pregabalin (450 mg/day), tramadol/acetaminophen (150 mg/1300 mg/día) and amitriptyline/fluoxetine (50mg/80 mg/día) for the treatment of FM. The clinical outcome considered was the annual rate of pain control. Probabilities assigned to the model were collected from published literature. Direct medical costs for FM treatment were retrieved from the 2006 data of the Mexican Institute of Social Security (IMSS) databases and were expressed in 2010 Mexican Pesos. Probabilistic Sensitivity Analyses were conducted. RESULTS: The best pain control rate was obtained with pregabalin (44.8%), followed by gabapentin (38.1%) and duloxetine (34.2%). The lowest treatment costs was for amitriptyline ($ 9047.01), followed by fluoxetine ($ 10,183.89) and amitriptyline/fluoxetine ($ 10,866.01). By comparing pregabalin vs amitriptyline, additional annual cost per patient for pain control would be around $ 50.000 and $ 75.000 and would result cost-effective in 70% and 80% of all cases. CONCLUSIONS: Among all treatment options for FM, pregabalin achieved the highest pain control and was cost-effective in 80% of patients of the Mexican Public Health System.

[Evaluation of health-related quality of life in patients with non-Hodgkin lymphoma and colorectal cancer at different stages, attending the Mexican Institute of Social Security]. / Evaluación de la calidad de vida en pacientes con linfoma no Hodgkin y cáncer colo-rectal en diferentes etapas clínicas atendidos en el Instituto Mexicano del Seguro Social.

INTRODUCTION: In Mexico during 2008, were reported 127,604 new cancer cases, 6,347 of them were colorectal cancer cases and 4,276 non-Hodgkin lymphoma (NHL) cases. OBJECTIVE: To evaluate health related quality of life in non-Hodgkin lymphoma and colorectal cancer cases in different clinical stages, attended in a High Specialty Medical facility at the Instituto Mexicano del Seguro Social, during a 13 month period. RESULTS: 162 patients were included, 56.8% (n=92) with NHL and 43.2% (n=70) with colorectal cancer. The scores obtained in the NHL group were: Global health status/QoL: 67.75 (± 27.55), physical functioning 69.64 (± 29.98), role functioning 71.38 (± 33.73), emotional functioning 69.7 (± 26.57), cognitive functioning 75.36 (± 28.01), social functioning 79.35 (± 29.38), fatigue 35.27 (± 28.27), nausea and vomiting 13.41 (± 21.85), pain 28.08 (± 30.25), dyspnea 19.20 (± 32.11), insomnia 30.80 (± 38.03), appetite lost 26.45 (± 36.16), constipation 19.20 (± 32.11), diarrhea 12.32 (± 26.48), financial difficulties 26.09 (± 35.57). In colorectal cancer patients the scores were: Global health status/QoL: 68.21 (± 24.46), physical functioning 67.38 (± 30.45), role functioning 65.48 (± 35.70), emotional functioning 66.43 (± 26.84), cognitive functioning 78.57 (± 26.49), social functioning 75.24 (± 31.05), fatigue 37.78 (± 31.62), nausea and vomiting 20.00 (± 28.32), pain 37.38 (± 34.45), dyspnea 11.90 (± 26.64), insomnia 28.09 (± 35.73), appetite lost 23.81 (± 36.40), constipation 19.05 (± 32.88), diarrhea 20.95 (± 31.17), financial difficulties 34.76 (± 38.67). CONCLUSIONS: With these basal results is important a follow-up with special attention to the treatment and attendance processes, in patients with this neoplasms and their impact on the quality of life.

[Quality of life in Mexican women with breast cancer at different stages and its association with sociodemographic characteristics, comorbidities and procedural factors at the Mexican Institute of Social Security]. / Calidad de vida en mujeres Mexicanas con cáncer de mama en diferentes etapas clínicas y su asociación con características socio-demográficas, estados co-mórbidos y características del proceso de atención en el Instituto Mexicano del Seguro Social.

INTRODUCTION: Quality of life is the most studied PRO (patient reported outcome) in cancer patients. With early diagnosis and better treatments in breast cancer, this entity has been transformed in a chronic disease with longer survival. The joint effects of diseases and treatment on quality of life are each day more important to consider in survival patients. OBJECTIVE: To evaluate quality of life, socioeconomic factors, co-morbidities, and the attendance process impact on quality of life in breast cancer women with different clinical stages attending at the Instituto Mexicano del Seguro Social using the EORCT QLQ-C30 RESULTS: The scores of EORTC QLQ-C30 (v3) were: Global health status / QoL: 73.47 (± 20.81), physical functioning 76.98 (± 20.85), role functioning 76.60 (± 27.57), emotional functioning 64.53 (± 26.81), cognitive functioning 74.47 (± 26.02), social functioning 84.96 (± 23.20), fatigue 31.94 (± 25.45), nausea and vomiting 19.49 (± 26.93), pain 28.95 (± 27.27), dyspnea 15.29 (± 24.62), insomnia 35.13 (± 32.10), appetite lost 18.04 (± 28.75), 18.04 (± 28.75), constipation 19.20 (± 32.11), diarrhea 12.9 (± 24.25), financial difficulties 40.57 (± 37.26). The scores with EORTC QLQ-BR23 were: body image 74.84 (± 31.69), sexual functioning 13.73 (± 22.55), sexual enjoyment 32.86 (± 36.17), future perspectives 51.69 (± 38.00), systemic therapy side effects 30.82 (± 20.71), breast symptoms 22.85 (± 23.49), arm symptoms 27.53 (± 24.75), upset by hair loss 43.80 (± 44.01). CONCLUSIONS: Clinical stage in breast cancer is associated with differences in the scores from fatigue, nausea and vomiting and financial difficulties according to the evolution of the disease and the physical detriment associated. Socio-demographic features were related role functioning, fatigue and pain in single women with higher scores.

[Evaluation of patient satisfaction with the quality of health care received within the EORTC IN-PATSAT32 trial by patients with breast and colorectal cancer, and non-Hodgkin lymphoma at different stages. Correlation with sociodemographic characteristics, comorbidities and other procedural variables at the Mexican Institute of Social Security]. / Análisis de la satisfacción con los cuidados en salud a través del cuestionario EORTC IN-PATSAT32 en pacientes con cáncer de mama, linfoma no Hodgkin y cáncer colo-rectal en diferentes etapas clínicas. Relación con las características socio-demográficas, estados co-mórbidos y variables del proceso de atención en el Instituto Mexicano del Seguro Social.

INTRODUCTION: In Mexico cancer is a public health burden. Nowadays the health care systems pay special attention to patient's perception and satisfaction of the health care received. Satisfaction with quality of health care has an impact in the adherence to the treatment. OBJECTIVE: To evaluate the satisfaction with the quality of health care received at the IMSS in a group of cancer patients [non Hodgkin lymphoma (NHL), breast and colorectal cancer]. Socio-demographic features, co-morbid diseases, and attendance processes impact on satisfaction are also evaluated. RESULTS: 476 cancer patients were studied: 314 with breast cancer, 92 with NHL and 70 with colorectal cancer. In women with breast cancer the mean score to nurses' interpersonal skills in non-classified disease group and clinical stage III group were: 73.64 ± 32.53, 90.00 ± 18.25 respectively (p=0.005), nurses' availability in non-classified and clinical stage III group were: 69.71 ± 30.25, 89.21 ± 19.00 respectively (p=0.003). In subjects with NHL the mean scores for doctors' technical skills in clinical stage I and III groups, were: 63.69 ± 37.78, 80.30 ± 18.46 respectively (p=0.017), doctors' information provision scores in subject in clinical stage I and IV were: 49.40 ± 40.75, 79.49 ± 24.63 respectively (p=0.043). In the group of colorectal cancer patients the mean of the score to exchange of information between clinical stage II and clinical stage III group were 50.00 ± 41.83, 84.21 ± 22.37 respectively (p=0.036). Were not observed association between attendance processes features and general satisfaction. CONCLUSIONS: In Mexico 50% of cancer patients are attended at the IMSS. The continued evaluation of the satisfaction with health care received by the health care service users is important to enhance attention's quality.

Cost-effectiveness of maraviroc for antiretroviral treatment-experienced HIV-infected individuals in Mexico.

OBJECTIVE: Maraviroc is the first approved drug in a new class of antiretrovirals, the CCR5 antagonists. The objective of this study was to predict the long-term clinical impact and cost-effectiveness of maraviroc in treatment-experienced adults with HIV/AIDS in Mexico. METHODS: The AntiRetroviral Analysis by Monte Carlo Individual Simulation (ARAMIS) model was adapted to the Mexican context to predict clinical and economic outcomes of treating with optimized background therapy (OBT) versus testing for viral tropism status and treating with OBT ± maraviroc accordingly in treatment-experienced adults in Mexico. Baseline characteristics and efficacy were from the MOTIVATE trials' screening cohort. Costs and population mortality data were specific to Mexico. Results were reported from the perspective of health care payers in 2008 Mexican pesos (converted to 2008 US$ in parentheses). RESULTS: Compared to treatment with OBT alone, treatment with OBT ± maraviroc contingent on tropism test result increased projected undiscounted life expectancy and discounted quality-adjusted life expectancy from 7.54 to 8.71 years and 4.42 to 4.92 quality-adjusted life years (QALYs), respectively, at an incremental cost of $228,215 (US$21,329). The resultant incremental cost-effectiveness ratio (ICER) was $453,978 (US$42,429) per QALY gained. The ICER was somewhat lower when maraviroc was modeled in individuals susceptible to ≤ 2 components of OBT ($407,329; US$38,069), while the ICER was higher in individuals susceptible to ≥3 OBT components ($718,718; US$67,171). CONCLUSION: In treatment-experienced individuals with HIV/AIDS in Mexico, maraviroc may be cost-effective, particularly in individuals with limited options for active antiretroviral therapy (ART).

Direct costs associated with the appropriateness of hospital stay in elderly population.

BACKGROUND: Ageing of Mexican population implies greater demand of hospital services. Nevertheless, the available resources are used inadequately. In this study, the direct medical costs associated with the appropriateness of elderly populations hospital stay are estimated. METHODS: Appropriateness of hospital stay was evaluated with the Appropriateness Evaluation Protocol (AEP). Direct medical costs associated with hospital stay under the third-party payer's institutional perspective were estimated, using as information source the clinical files of 60 years of age and older patients, hospitalized during year 2004 in a Regional Hospital from the Mexican Social Security Institute (IMSS), in Mexico City. RESULTS: The sample consisted of 724 clinical files, with a mean of 5.3 days (95% CI = 4.9-5.8) of hospital stay, of which 12.4% (n = 90) were classified with at least one inappropriate patient day, with a mean of 2.2 days (95% CI = 1.6-2.7). The main cause of inappropriateness days was the inexistence of a diagnostic and/or treatment plan, 98.9% (n = 89). The mean cost for an appropriate hospitalization per patient resulted in US$1,497.2 (95% CI = US$323.2-US$4,931.4), while the corresponding mean cost for an inappropriate hospitalization per patient resulted in US$2,323.3 (95% CI = US$471.7-US$6,198.3), (p < 0.001). CONCLUSION: Elderly patients who were inappropriately hospitalized had a higher rate of inappropriate patient days. The average of inappropriate patient days cost is considerably higher than appropriate days. In this study, inappropriate hospital-stay causes could be attributable to physicians and current organizational management.

Tratamiento antimicótico empírico de pacientes inmunocomprometidos con neutropenia y fiebre persistente con sospecha de aspergilosis sistémica: análisis de costo-efectividad en México / Empirical anti-mycotic treatment of immunocompromised patients with neutropenia and persistent fever with suspicion of systemic aspergillosis: Cost-effectiveness study in Mexico

Introducción. Las micosis sistémicas generan un gran incremento en los costos de la atención médica. Se evaluó el medicamento más costo-efectivo para el tratamiento empírico de aspergilosis sistémica entre la anfotericina B, caspofungina y voriconazol en pacientes con fiebre persistente y neutropenia. Métodos. Modelo tipo árbol de decisiones para estimar los resultados clínicos esperados y los costos asociados del tratamiento de la aspergilosis sistémica. La perspectiva del estudio fue la del proveedor de servicios públicos de salud (Instituto Mexicano del Seguro Social [IMSS]). Temporalidad: 12 semanas. Medida de efectividad: tasa de remisión completa de la infección micótica. Se desarrollaron análisis de sensibilidad univaridos y probabilísticos. Resultados. Los costos totales promedio por paciente esperados para el tratamiento empírico de aspergilosis resultaron convoriconazol en $57 378.58 US; $72 833.96 US con anfotericina B, y de $49 962.37 US con caspofungina. La tasa de remisión total sin eventos adversos fue de 37% para caspofungina, 43.6% para voriconazol y de 51.1% para anfotericina B. El análisis de sensibilidad probabilístico muestra que voriconazol sería el tratamiento más costo-efectivo en 65% de los casos, independientemente de la disposición a pagar por el IMSS. Conclusiones. Los resultados presentados concuerdan con la afirmación de que el tratamiento estándar de primera línea recientemente propuesto para el tratamiento empírico de aspergilosis sistémica debe ser voriconazol.

Introduction. Systemic mycosis has a great impact on medical care costs. The objective of this study was to assess the most cost-effective empirical treatment for systemic aspergillosis, evaluating amphotericin B, caspofungin and voriconazole in patients with persistent fever and neutropenia. Methods. A decision-tree model was used to estimate expected clinical results and costs associated with the treatment for systemic aspergillosis. The study used a healthcare payer's perspective (Mexican Institute of Social Security, IMSS). Time frame was 12 weeks. Effectiveness measure was complete remission of mycotic infection. One-way and probabilistic sensitivity analyses were performed. Results. Average total expected costs per patient for the voriconazole treatment were US $57 378.58, for amphotericin B US $72 833.96, and for caspofungin were US $49 962.37. Thetotal expected remission rate without any adverse events was 37% for caspofungin, 43.6% for voriconazole and 51.1% for amphotericin B. Probabilistic sensitivity analysis showed that voriconazole would be a cost-effective treatment with 65% confidence, regardless of the willingness to pay the IMSS. Conclusions. The results of the study agree with the recommendation that voriconazole must be the empirical treatment for systemic aspergillosis, proposed as a standard first-line antifungal drug.

El concepto de willingness-to-pay en tela de juicio: [revisión] / The willingness-to-pay concept in question: [review]

La idoneidad del concepto de willingness to pay (disponibilidad a pagar) es revisado en las evaluaciones económicas que se realizan en el campo de la salud. Por un lado, existe dentro de la literatura económica un número importante de investigadores que señalan los múltiples problemas metodológicos que entrañan las estimaciones de willingness to pay. Por otro lado, aún el debate teórico-conceptual acerca de la agregación de las preferencias individuales dentro de una demanda agregada no ésta del todo resuelto. Sin embargo, durante los últimos 20 años la estimación de la disponibilidad a pagar dentro de las investigaciones económicas ha aumentado de forma significativa, siendo en muchos casos uno de los principales factores de la toma de decisión en políticas de salud. Plantease alguna de las limitaciones de esta técnica, así como el posible efecto distorsionador que podría tener sobre las evaluaciones económicas que se realizan en el área de la economía de la salud.

The adequacy of the concept of willingness to pay within health economics evaluations is reviewed. A considerable number of researchers in the literature have pointed out multiple methodological issues involving willingness-to-pay estimates. On the other hand, the theoretical discussion about the aggregation of individual preferences within an aggregate demand remains open. However, over the last 20 years, willingness-to-pay estimates alongside health economics research significantly increased and in many cases they are one of the key factors for decision making on issues of health policies. The article describes some limitations of this approach as well as the potential distorting effect that it might have on health economics evaluations.

São revisadas as limitações do uso do conceito de willingness to pay (disposição a pagar) nas avaliações econômicas que se realizam no campo da saúde. Há na literatura econômica muitos investigadores que assinalam os múltiplos problemas metodológicos inerentes às estimações de willingness to pay. Por outro lado, o debate teórico-conceitual acerca da agregação das preferências individuais dentro de uma demanda agregada não está totalmente resolvido. Contudo, durante os últimos 20 anos, a estimação da disposição a pagar calculada pelos estudos tem aumentado de forma significativa, sendo em muitos casos um dos principais fatores de tomada de decisão em políticas de saúde. São apresentadas algumas das limitações desta técnica, assim como o possível efeito de distorção que poderia ter sobre as avaliações econômicas em saúde.

[The willingness-to-pay concept in question]. / El concepto de willingness-to-pay en tela de juicio.

The adequacy of the concept of willingness to pay within health economics evaluations is reviewed. A considerable number of researchers in the literature have pointed out multiple methodological issues involving willingness-to-pay estimates. On the other hand, the theoretical discussion about the aggregation of individual preferences within an aggregate demand remains open. However, over the last 20 years, willingness-to-pay estimates alongside health economics research significantly increased and in many cases they are one of the key factors for decision making on issues of health policies. The article describes some limitations of this approach as well as the potential distorting effect that it might have on health economics evaluations.

Cost-effectiveness simulation analysis of schizophrenia at the Instituto Mexicano del Seguro Social: Assessment of typical and atypical antipsychotics.

INTRODUCTION: Estimation of the economic costs of schizophrenia is a fundamental tool for a better understanding of the magnitude of this health problem. The aim of this study was to estimate the costs and effectiveness of five antipsychotic treatments (ziprasidone, olanzapine, risperidone, haloperidol and clozapine), which are included in the national formulary at the Instituto Mexicano del Seguro Social, through a simulation model. METHODS: Type of economic evaluation: complete economic evaluation of cost-effectiveness. STUDY PERSPECTIVE: direct medical costs. TIME HORIZON: 1 year. Effectiveness measure: number of months free of psychotic symptoms. ANALYSIS: to estimate cost-effectiveness, a Markov model was constructed and a Monte Carlo simulation was carried out. RESULTS: Effectiveness: the results of the Markov model showed that the antipsychotic with the highest number months free of psychotic symptoms was ziprasidone (mean 9.2 months). The median annual costs for patients using ziprasidone included in the hypothetical cohort was 194,766.6 Mexican pesos (MXP) (95% CI, 26,515.6-363,017.6 MXP), with an exchange rate of 1 € = 17.36 MXP. The highest costs in the probabilistic analysis were estimated for clozapine treatment (260,236.9 MXP). CONCLUSIONS: Through a probabilistic analysis, ziprasidone showed the lowest costs and the highest number of months free of psychotic symptoms and was also the most costeffective antipsychotic observed in acceptability curves and net monetary benefits.

Cost-effectiveness analysis for joint pain treatment in patients with osteoarthritis treated at the Instituto Mexicano del Seguro Social (IMSS): Comparison of nonsteroidal anti-inflammatory drugs (NSAIDs) vs. cyclooxygenase-2 selective inhibitors.

BACKGROUND: Osteoarthritis (OA) is one of the main causes of disability worldwide, especially in persons >55 years of age. Currently, controversy remains about the best therapeutic alternative for this disease when evaluated from a cost-effectiveness viewpoint. For Social Security Institutions in developing countries, it is very important to assess what drugs may decrease the subsequent use of medical care resources, considering their adverse events that are known to have a significant increase in medical care costs of patients with OA. Three treatment alternatives were compared: celecoxib (200 mg twice daily), non-selective NSAIDs (naproxen, 500 mg twice daily; diclofenac, 100 mg twice daily; and piroxicam, 20 mg/day) and acetaminophen, 1000 mg twice daily. The aim of this study was to identify the most cost-effective first-choice pharmacological treatment for the control of joint pain secondary to OA in patients treated at the Instituto Mexicano del Seguro Social (IMSS). METHODS: A cost-effectiveness assessment was carried out. A systematic review of the literature was performed to obtain transition probabilities. In order to evaluate analysis robustness, one-way and probabilistic sensitivity analyses were conducted. Estimations were done for a 6-month period. RESULTS: Treatment demonstrating the best cost-effectiveness results [lowest cost-effectiveness ratio $17.5 pesos/patient ($1.75 USD)] was celecoxib. According to the one-way sensitivity analysis, celecoxib would need to markedly decrease its effectiveness in order for it to not be the optimal treatment option. In the probabilistic analysis, both in the construction of the acceptability curves and in the estimation of net economic benefits, the most cost-effective option was celecoxib. CONCLUSION: From a Mexican institutional perspective and probably in other Social Security Institutions in similar developing countries, the most cost-effective option for treatment of knee and/or hip OA would be celecoxib.

The hospital appropriateness evaluation protocol in elderly patients: a technique to evaluate admission and hospital stay.

BACKGROUND: Aging of the population represents one of the main challenges for health systems because of the increase in the demand for hospital services. To be able to count on tools that allow an objective evaluation of hospital-resource use becomes indispensable for health systems. OBJECTIVE: To evaluate the reliability and validity of the Appropriateness Evaluation Protocol (AEP) regarding the appropriateness of admissions and hospital stays in elderly patients. In a scenario of scarce resources, to have a valid instrument will make it possible to evaluate the process of care in our growing elderly population in a standardized way. METHODS: We carried out a retrospective study of 144 randomly chosen elderly patients admitted to the hospital with 394 even-numbered hospital-stay days. For the reliability analysis between the pair of nurses with the AEP and the pair of specialists, the details of the hospital admissions and the stay days were obtained from the clinical files. Criteria validity was conducted by pairs of physicians, including two internists, two general surgeons and two geriatricians. Only the agreements were compared with agreements of the AEP-trained nurses. Disagreements were excluded from the final analysis. RESULTS: Inter-rater (inter-reviewer) agreement of hospital admissions and days spent by the patient presented a kappa coefficient of >0.70, while these admissions and hospital-stay days was >0.70. Sensitivity and positive predictor value to detect inappropriate admissions were not calculated because no agreement existed on inappropriate admissions. Specificity and negative predictive value to detect appropriate admission was >94.0% and >98.0%. Sensitivity and positive predictor value to detect inappropriate hospital-stay days was >44.0% and >10.0%, while specificity and negative predictor value for detecting appropriate hospital-stay days was >79.0% and >88.0%. CONCLUSIONS: AEP's high-reliability and moderate-validity results with regard to clinical judgement positions it as a useful instrument for appropriate hospitalization screening in elderly patients.

[Competitiveness in the health care sector: analysis of the Swedish reform (1992-1995)]. / Competencia en el sector salud: análisis de la reforma sueca (1992-1995).

The paper reviews the outcomes and failures of the Swedish health care reform, as well as the lessons learned for accomplishing better financial results and quality standards.

Competencia en el sector salud: análisis de la reforma sueca (1992 - 1995): [comentarios] / Competitiveness in the health care sector: analysis of the Swedish reform (1992-1995): [comment]

El artículo revisa los éxitos y fracasos de la reforma sueca de salud, así como las lecciones que dejó en su afán de alcanzar mejores resultados financieros y estándares de calidad.

The paper reviews the outcomes and failures of the Swedish health care reform, as well as the lessons learned for accomplishing better financial results and quality standards.

Una mirada desde los servicios de salud a la nutrición de la niñez mexicana: III. Carga económica y en salud de la obesidad en niños mexicanos. Proyecciones de largo plazo / A look from health services to the nutrition of Mexican childhood: III. Economic and health burden of Mexican childhood obesity. Long-term projections

Objetivo. Estimar la carga económica y en salud de la obesidad en niños mexicanos en un horizonte de largo plazo. Estimación de costos médicos atribuibles a la obesidad en niños mexicanos durante 2006-2050. Una cohorte hipotética de 5-11 años de edad obesa se modeló con base en prevalencia, incidencia y evolución clínica. Los costos considerados fueron por diabetes mellitus tipo 2 e hipertensión arterial. En 2015 se presentarían los primeros casos de diabetes mellitus y de hipertensión arterial. Cuando el primer grupo de niños cumpla 40 años aumentarán considerablemente las complicaciones de la obesidad. Para 2050, 67.3% de la cohorte tendría obesidad. El costo de atención a la obesidad será de $57 678 millones de pesos. La magnitud de la obesidad se reporta en niveles preocupantes en todas las edades, con costos que consumirán buena parte de los recursos del sistema de salud.

Objective. To estimate the economic and health burden of childhood obesity in Mexican population over the long term. This study estimates healthcare costs due to child obesity in Mexican children from 2006-2050. A hypothetic 5-11-year-old obese cohort based on prevalence, incidence, and clinical development data was modelled. Cost allocation considerations include type 2 diabetes mellitus and high blood pressure. The first cases of diabetes mellitus and with a risk of high blood pressure appears in the year 2015. When the first group of children is 40 years old, there is a considerable increase in obesity-related complications. A total of 67.3% of the cohort would have obesity in the year 2050. The cost of obesity care would be $57 678 million Mexican pesos. The magnitude of obesity reported is at worrisome levels in all age groups, showing costs that would consume a high percentage of the health system’s resources.