Likelihood ratios of clinical, laboratory and image data of pancreatic cancer: Bayesian approach

PURPOSE

The diagnosis of pancreatic cancer (PC) is most frequently established in advanced stages. The aim of this study is to estimate the likelihood ratios (LRs) of diagnostic data with regards to PC that could be used to approach an earlier diagnosis.

METHODS

A case-control study of 300 patients - 150 histological diagnosed cases of PC and 150 age-matched controls hospitalized for study of jaundice, abdominal pain, weight loss and/or chronic pancreatitis - was conducted. Bayesian probabilities in the form of LRs were estimated for PC predictions.

RESULTS

Probability of PC was associated with jaundice [odds ratio (OR) 2.89; confidence interval (CI) 1.71-4.85], glycemic disturbance (OR 5.64; CI 2.36-13.46), tobacco index >20 (OR 2.11; CI 1.08-4.09) and tumour marker CA 19-9 (OR 9.33; CI 1.36-63.95). Computed tomography showed the highest test performance with regards to PC when comparing with other diagnostic tests. LRs for variables relevant to PC were estimated, among the most relevant: jaundice LR + 1.92, CA 19-9 LR + 5.36 and computed tomography LR + 4.15. The prediction model with an endoscopic retrograde cholangiopancreatography at a tertiary referral hospital determined a 67% probability of detecting PC.

CONCLUSIONS

Through a Bayesian approach we can combine clinical, laboratory and imaging data to approximate to an earlier diagnosis of PC.

Economic burden of expected epidemiological changes in diseases related to tobacco, Mexico

OBJECTIVE

To determine health care costs and economic burden of epidemiological changes in diseases related to tobacco consumption.

METHODS

A time-series analysis in Mexico (1994-2005) was carried out on seven health interventions: chronic obstructive pulmonary diseases, lung cancer with and without surgical intervention, asthma in smokers and non-smokers, full treatment course with nicotine gum, and full treatment course with nicotine patch. According with Box-Jenkins methodology, probabilistic models were developed to forecast the expected changes in the epidemiologic profile and the expected changes in health care services required for selected interventions. Health care costs were estimated following the instrumentation methods and validated with consensus technique.

RESULTS

A comparison of the economic impact in 2006 vs. 2008 showed 20-90% increase in expected cases depending on the disease (p<0.05), and 25-93% increase in financial requirements (p<0.01). The study data suggest that changes in the demand for health services for patients with respiratory diseases related to tobacco consumption will continue showing an increasing trend.

CONCLUSIONS

In economic terms, the growing number of cases expected during the study period indicates a process of internal competition and adds an element of intrinsic competition in the management of preventive and curative interventions. The study results support the assumption that if preventive programs remain unchanged, the increasing demands for curative health care may cause great financial and management challenges to the health care system of middle-income countries like Mexico.

Epidemiologic changes and economic burden of hypertension in Latin America: evidence from Mexico

BACKGROUND

Costs of health services for hypertension and the financial consequences of epidemiologic changes in this disease are important concerns for health systems in Latin America.

METHODS

We conducted longitudinal analyses of the economic impact of the epidemiologic changes on health care services for hypertension in the Mexican health care system. The cost evaluation method used was based on costing technique by production function and consensus techniques. To estimate the epidemiologic changes and financial consequences for the period 2005 to 2007, three probabilistic models were constructed according to the Box-Jenkins technique.

RESULTS

If changes are not implemented in prevention programs to reduce the effects of current risk factors, there will be increases in the number of patients with hypertension as well as in the financial burden to treat the disease. The amount allocated for hypertension in 2007, which will be 6% to 8% of the total health budget, is US$ 2,486,145,132. Of these, US$ 1,178,725,132 will be direct costs and US$ 1,307,420,000 will be indirect costs. Regarding epidemiologic changes for 2005 v 2007 (P < .05), an increase is expected, although results show a greater increase in insured populations.

CONCLUSIONS

If the risk factors and different health programs remain as they currently are, the economic impact of expected epidemiologic changes on the social security system will be particularly strong. Another relevant financial factor is the appearance of internal competition in the allocation of financial resources among the main providers of health services for hypertension; this factor becomes even more complicated within each provider.

Effects of health decentralization, financing and governance in Mexico

OBJECTIVE: To identify the effects of decentralization on health financing and governance policies in Mexico from the perspective of users and providers. METHODS: A cross-sectional study was carried out in four states that were selected according to geopolitical and administrative criteria. Four indicators were assessed: changes and effects on governance, financing sources and funds, the final destination of resources, and fund allocation mechanisms. Data collection was performed using in-depth interviews with health system key personnel and community leaders, consensus techniques and document analyses. The interviews were transcribed and analyzed by thematic segmentation. RESULTS: The results show different effectiveness levels for the four states regarding changes in financing policies and community participation. Effects on health financing after decentralization were identified in each state, including: greater participation of municipal and state governments in health expenditure, increased financial participation of households, greater community participation in low-income states, duality and confusion in the new mechanisms for coordination among the three government levels, absence of an accountability system, lack of human resources and technical skills to implement, monitor and evaluate changes in financing. CONCLUSIONS: In general, positive and negative effects of decentralization on health financing and governance were identified. The effects mentioned by health service providers and users were related to a diversification of financing sources, a greater margin for decisions around the use and final destination of financial resources and normative development for the use of resources. At the community level, direct financial contributions were mentioned, as well as in-kind contributions, particularly in the form of community work.

Health care costs and financial consequences of epidemiological changes in chronic diseases in Latin America: evidence from Mexico

OBJECTIVE

To determine the costs of health services and the financial consequences of changes in the epidemiological profile of chronic diseases in Latin America.

STUDY DESIGN

We conducted longitudinal analyses of costs and of the economic impact of the epidemiological transition in healthcare services for diabetes and hypertension in the Mexican health system. The study population included both the insured and uninsured populations.

METHODS

The cost-evaluation method was based on the instrumentation and consensus techniques. To estimate the epidemiological changes and financial consequences for 2004-2006, six models were constructed according to the Box-Jenkins technique, using confidence intervals of 95% and the Box-Pierce test.

FINDINGS

Costs ranged from US$613 to US$887 for diabetes, and from US$485 to US$622 for hypertension. Regarding epidemiological changes for 2004 compared with 2006, an increase is expected in both cases, although results predict a greater increase for diabetes, 10-15% in all three institutions (P<0.05). Comparing the financial consequences of health services required by insured and uninsured populations, the greater increase (17%) will be for the insured population (P<0.05). The financial requirements for both diseases will amount to 9.5% of the total budget for the uninsured population and 13.5% for the insured population.

CONCLUSIONS

If the risk factors and the different healthcare models remain as they are at present, the economic impact of expected epidemiological changes on the social security system will be particularly strong. Another relevant financial factor is the appearance of internal competition in the use and allocation of financial resources among the main providers in the health services; this factor becomes even more complicated within each provider. In effect, within each institution, hypertension and diabetes programmes must compete for resources with other programmes for chronic and infectious diseases.

The impact of losartan on the lifetime incidence of ESRD and costs in Mexico

BACKGROUND

The RENAAL (Reduction of Endpoints in Type 2 Diabetes with the Angiotensin II Antagonist Losartan) study demonstrated that treatment with losartan reduced the risk of ESRD by 29% among hypertensive patients with type 2 diabetes and diabetic nephropathy. The objective of this study was to project the effect of losartan compared to placebo on the lifetime incidence of ESRD and associated costs from a third-party payer perspective in Mexico.

METHODS

A competing risks method was used to estimate lifetime incidence of ESRD, while accounting for the risk of death without ESRD. The cost associated with ESRD was estimated by combining the cumulative incidence of ESRD with the lifetime cost associated with ESRD. Total cost was estimated as the sum of the cost associated with ESRD from the three main public institutions in Mexico, the lifetime cost of losartan therapy, and other costs (non-ESRD/non-losartan) expected for patients with type 2 diabetes. Survival was estimated by weighting the life expectancies with and without ESRD by the cumulative risk of ESRD.

RESULTS

The projected lifetime incidence of ESRD for losartan patients was lower (66%) compared with placebo patients (83%). This reduction in ESRD resulted in a decrease in ESRD-related cost of M dollar 49,737 per patient and a discounted gain of 0.697 life years per patient. After accounting for the cost of losartan and the additional cost associated with greater survival, we projected that treatment with losartan would result in a net savings of M dollar 24,073 per patient.

CONCLUSION

Treatment with losartan in patients with type 2 diabetes and nephropathy not only reduced the within-trial incidence of ESRD but is projected to result in lifetime reductions in ESRD, increased survival, and overall cost savings to public institutions in Mexico.

Who pays more for health services in middle-income countries: lessons from Mexico

An evaluative study with a cross-sectional design was carried out on healthcare cost indicators reported by the 2000 National Health Survey in Mexico, to determine which population group had higher health costs/expenditures in relation to family income. The results suggest that in middle-income countries such as Mexico, families with lower incomes tend to pay more for healthcare services.

Evidences on weaknesses and strengths from health financing after decentralization: lessons from Latin American countries

OBJECTIVE

The main objective was to identify trends and evidence on health financing after health care decentralization.

STUDY DESIGN

Evaluative research with a before-after design integrating qualitative and quantitative analysis. Taking into account feasibility, political and technical criteria, three Latin American countries were selected as study populations: Mexico, Nicaragua and Peru.

DATA SOURCES

The methodology had two main phases. In the first phase, the study referred to secondary sources of data and documents to obtain information about the following variables: type of decentralization implemented, source of finance, funds of financing, providers, final use of resources and mechanisms for resource allocation. In the second phase, the study referred to primary data collected in a survey of key personnel from the health sectors of each country.

FINDINGS

The trends and evidence reported in all five financing indicators may identify major weaknesses and strengths in health financing.

CONCLUSIONS

Weaknesses: a lack of human resources trained in health economics who can implement changes, a lack of financial resource independence between the local and central levels, the negative behavior of the main macro-economic variables, and the difficulty in developing new financing alternatives. Strengths: the sharing between the central level and local levels of responsibility for financing health services, the implementation of new organizational structures for the follow-up of financial changes at the local level, the development and implementation of new financial allocation mechanisms taking as a basis the efficiency and equity principles, new technique of a per-capita adjustment factor corrected at the local health needs, and the increase of financing contributions from households and local levels of government.

Efectos de la descentralización en el financiamiento de la salud en México

OBJETIVO: Identificar las tendencias y los efectos de la descentralización en las políticas de financiamiento de la salud en México. MÉTODOS: La población de estudio incluyó cuatro estados seleccionados bajo criterios técnicos: diferente desarrollo socio-económico; implementación de la descentralización; base de datos sobre información económica; confiabilidad y validéz de las bases de datos; y apoyo de un equipo interdisciplinario de investigación. Las técnicas de recopilación de información se basaron en entrevistas a profundidad con personal clave y análisis de documentos y bases de datos sobre los presupuestos estatales en salud para el período 1990-2000. RESULTADOS: El modelo de análisis propuesto permitió identificar las tendencias y efectos de la descentralización sobre las principales fuentes de financiamiento en salud: Hogares, Gobiernos Federal, Estatal y Municipal. Hay evidencias de niveles de efectividad muy variada en cuanto a los cambios en las políticas de financiamiento, particularmente en lo que se refiere a las tendencias en los montos económicos por tipo de fuente de financiamiento. CONCLUSIONES: Hay estados donde los hogares, los municipios y el mismo gobierno estatal han hecho efectivo un incremento importante en el financiamiento de la salud, pero también hay Estados donde continúa la dependencia económica del nivel federal y donde Hogares, Municipios y Estados no están dispuestos ni capacitados para asumir responsabilidad económica en materia de salud.

Economic consequences of epidemiological changes in diabetes in middle-income countries: the Mexican case

OBJECTIVE

To identify the costs and economic consequences of expected changes in the demand for health care services for type 2 diabetes in the three main public institutions of the Mexican health care system.

RESEARCH DESIGN AND METHODS

The cost evaluation method to estimate direct and indirect costs was based on instrumentation and consensus techniques. To estimate the costs and epidemiological changes for 2003-2005, three probabilistic models were constructed according to the Box-Jenkins technique.

RESULTS

Comparing the economic impact in 2003 versus 2005 (P < 0.05), there is a 26% increase in financial requirements. The total amount for diabetes in 2005 (in U.S. dollars) will be 317,631,206, dollars including 140,410,816 dollars in direct costs and 177,220,390 dollars in indirect costs. The total direct costs, representing financial requirements to provide health care for expected cases of type 2 diabetes and its main complications in the three main public institutions in Mexico, up to 2005, will be 37,079,587 dollars for the Ministry of Health (or Secretaría de Salud [SSA], serving the uninsured population) and 103,331,235 dollars for the Mexican Social Security Institute, or Instituto Mexicano del Seguro Social (IMSS), and the Institute for Social Security and Services for State Workers, or Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado (ISSSTE), both of which serve the insured population.

CONCLUSIONS

Our data suggest that changes in the demand for health care services for patients with diabetes will continue with an increasing trend, mainly in the insured population. In economic terms, the results of direct and indirect costs are one of the main challenges to be solved to decrease the economic burden that diabetes represents for the population, the health care institutions, and for society as a whole.

Road traffic injuries in an urban area in Mexico. An epidemiological and cost analysis

The objective of this study was to do an epidemiological and costs analysis of the impact of road traffic injuries on the demand for emergency room services at hospitals located in the city of Cuernavaca, Mexico. The studied population included injured people who demanded medical attention at the emergency room for injuries due to events in public places, occurring between February and April 2001. Trained interviewers collected the data at the emergency room, 24h a day. The statistical analysis included simple and bivariate analysis using chi(2) odds ratio (OR), and a confidence interval of 95%. The costs analysis included the expenses during the process of searching for and finding care for injuries. There were 433 injured people, 233 (54%) were victims of road traffic accidents, 72% of crashes, and 28% were injured pedestrian and cyclists. Variables associated with the demand of emergency care due to road traffic injuries in comparison with other accidents, were: severity of injuries (OR 2.60, CI 1.44-4.71), and thorax injury (OR 4.64, CI 1.03-20.89). Pedestrians had higher costs for health care and 80% of them had to pay out-of-pocket (P<0.05). Differences between patients injured by crashes or as a pedestrian, were: age under 14 years (OR 5.9, CI 2.5-13.9), being unemployed (OR 2.1, CI 1.20-3.96), and being an elementary school student (OR 13.9, CI 3.08-63.13). The present study is, so far, the only one in Mexico to include an epidemiological and costs analysis in approaching the problem of road traffic injuries. Similar methods must be used, especially in developing countries, to reduce this important public health problem.

[Search for medical care and determinants of the health services utilization]

There are four different conceptual approaches to assess the factors that explain, condition and determine the use of health services. This article discusses the epidemiological, psychosocial, sociological and economical models. The stages and determinants of the health service use process are described and a cross study is made with each of the four models, using a contingency matrix. A holistic analysis is proposed, as a starting point, for the search of a model that will allow the identification of factors that determine the use of health services. This analysis should be used as a conceptual framework for future work on health services utilization.

[Economic evaluation of the demand of medical care for mental health in Mexico: schizophrenia and depression, 1996-2000]

Financing protection for both, users and providers of health care services is one of the main objectives of National Program of Health in Mexico, 2001-2006. In fact one of the elements of the present health care reform initiatives is need for the efficient allocation of financial resources, using resource allocation schemes by specific health care demands that combine both the economic, clinical and the epidemiological perspectives. The evaluation of such schemes has been approached in several ways; however, in the case of mental health services, there is dearth of studies that use economic assessment methods. Moreover, such studies are of limited scope, often a response to unmated health needs, disregarding the economic implication for health services production and financing and ensuing medical care market imbalances. This paper presents the results of an evaluative research work aimed to assess the average cost of depression and schizophrenia case management, the financial resources required to meet the health care demands by type of institution, period 1996-2000, in Mexico by type of health care provider. The case management average cost for schizophrenia was $211.00 US, and that for depression was $221.00 US. The demand of services for both conditions in each type of institution showed that the greatest relative demands (96% of the national total for depression and 94% of the national total for schizophrenia) occur in three institutions: IMSS, SSA and ISSSTE. The greatest demand of the health services for the two study condition corresponded to those insured by the IMSS, followed by those uninsured who use the SSA services, and those insured by the ISSSTE. The case management costs for mental conditions are in the middle range between hypertension and diabetes in the upper end, pneumonia and diarrhea in the lower end. The case managment costs of health care demands for the selected tracer conditions differ considerably among institutions for insure populations and those for uninsured populations, with a greater economic impact on-the former. Independent from differences found, these results allow the identification of economic evaluation indicators that could be used to design resource allocation schemes for each of the institutions included in this study.

Financial consequences of changes in health care demands related to tobacco consumption in Mexico: information for policy makers

This paper presents the results from a longitudinal study in which the main purpose was to determine the health-care costs and financial consequences of changes in the health care demands related to tobacco consumption in Mexico. Eleven health interventions were selected to conduct this study and four probabilistic models were developed to forecast the expected changes in the epidemiologic profile of selected diseases. The costing method was based on the identification of case management costs using the instrumentation and consensus techniques, probabilistic models were designed using the Box-Jenkins technique and allowed us to identify the expected case trends for the 2001-2003 period. The generation of information on case management costs for the selected interventions is a central instrument in the planning of health programs, above all in that which refers to resource allocation by type of demand. On the other hand, the identification of expected cases and the financial consequences allowed us to know the growing trends of the sums required to satisfy health care demands for the period under study. The three types of information are a relevant resource for decision-makers in the production and financing of health services.

[Financial requirements for health services demands for diabetes and hypertension in Mexico: 2001-2003]

This paper presents the results of a prospective study aimed at identifying financial requirements to provide and finance healthcare services during the period 2001-2003, for high blood pressure and diabetes, the two main chronic diseases demanding healthcare services in Mexico. The study population was drawn from Mexico's three main healthcare institutions: The Ministry of Health (SSA); the Mexican Institute of Social Security (IMSS); and the Institute for Social Security and Services for State Workers (ISSSTE). The costing method was based on instrumentation and consensus techniques per average case management. Six Box-Jenkins probabilistic models were constructed to estimate the epidemiologic change for the period 2001-2003. Study findings suggest that if risk factors and healthcare provision models remain unchanged, the financial consequences would have a greater impact on the Ministry of Health, followed by IMSS and ISSSTE. Financial requirements for both diseases will account for nearly 2% of the total budget allocated to the uninsured, and 3.5% for the insured population. Indirect costs showed a similar trend in the three institutions, representing nearly 23% above total direct costs.

[Trends on generation and reproduction of knowledge about economic evaluation and health]

This paper identifies the trends and recent progress in the generation and reproduction of knowledge on health economic evaluation. Analysis is organized along nine public health action fields, namely: health determinants and predictors, economic value of health, healthcare demand, healthcare supply, microeconomic evaluation of healthcare, healthcare market balance, evaluation of policy instruments, general evaluation of the health system, and healthcare planning, regulation and supervision. Each action field is defined to place the reader in the proper setting and level of analysis. In addition, thematic research topics developed in each action field are proposed and discussed. The generation and reproduction of knowledge on the different action fields was based on the review of the bibliographic databases MEDLINE and LILACS for the 1992-2000 period. Results lead to the conclusion that development and application of economic evaluation of healthcare has been uneven across different countries and that there is a growing increase of applications starting in 1994, the year of initiation of healthcare reform in Latin America.

Financing indicators for health care decentralization in Latin America: information and suggestions for health planning

This article presents the results from an evaluative longitudinal study with before-after design. The main objective was to determine the effects of health care decentralization on changes in health financing. Taking into account feasibility, political and technical criteria, three Latin American countries were selected as study populations: Mexico, Nicaragua and Peru. The methodology had two main phases. In the first phase, the study referred to secondary sources of data and documents to obtain information about the following variables: type of decentralization implemented, source of finance, funds of financing, providers, final use of resources and mechanisms for resource allocation. In the second phase, the study referred to primary data collected in a survey of key personnel from the health sectors of each country. Taking into account the changes implemented in the three countries, as well as the strengths and weaknesses of each country in financing and decentralization, a rule for decision-making is proposed that attempts to identify the main financial changes implemented in each country and the basic indicators that can be used in future years to direct the planning, assessment, adjustment and correction of health financing and decentralization.

Health financing changes in the context of health care decentralization: the case of three Latin American countries

OBJECTIVE

The results of an evaluative longitudinal study, which identified the effects of health care decentralization on health financing in Mexico, Nicaragua and Peru are presented in this article.

METHODS

The methodology had two main phases. In the first, secondary sources of data and documents were analyzed with the following variables: type of decentralization implemented, source of financing, funds for financing, providers, final use of resources, mechanisms for resource allocation. In the second phase, primary data were collected by a survey of key personnel in the health sector.

RESULTS

Results of the comparative analysis are presented, showing the changes implemented in the three countries, as well as the strengths and weaknesses of each country in matters of financing and decentralization.

CONCLUSIONS

The main financing changes implemented and quantitative trends with respect to the five financing indicators are presented as a methodological tool to implement corrections and adjustments in health financing.

Endoscopic treatment of sinonasal disease in patients who have had orthognathic surgery

Certain skeletofacial patterns may be predisposed to aggravated sinonasal disease postoperatively. These may include, but are not limited to, facial skeletal asymmetries with high septal deviations and those with obstructive nasal respiration and mouth breathing that leads to skeletal growth disturbances such as vertical maxillary hyperplasia and apertognathism. These sinonasal diseases may partly be the result of osteomeatal blockage by pre-existing structures, or synechial shelves and webs blocking normal maxillary antral mucosal flow. The use of nasal antral windows placed anteriorly in the lateral nasal wall at the time of downfracture LeFort (Hosaka window) do not seem to benefit the drainage of the maxillary antrum. This is because physiological flow often bypasses this region. If patients present postoperatively with new sinonasal disease or the aggravation of pre-existing symptoms, evaluation by both endoscopically assisted intranasal and axially and coronal computed tomography (CT) is recommended. Functional endoscopic sinus surgery by the minimally invasive Messerklinger technique, combined with intranasal use of laser-assisted turbinoplasty and soft tissue lysis, have been successfully used for most of these patients. Because the anatomical positioning of the midfacial structure can potentially affect patients with a predisposition to sinonasal physiological disturbances, consideration should be given to preoperative evaluation and discussion of potential consequences.

[Analysis of participation in surveys in 5 countries: the importance for public health research]

This study compares participation rates and reasons for nonresponse in surveys conducted in five countries of Latin America and the Caribbean. The objective of the surveys was to measure the prevalence of risk behaviors affecting the transmission of human immunodeficiency virus. The surveys were based on probability samples of the population of both sexes between 15 and 49 years old, except in Mexico, where only men were included. Proportions of three components of participation were estimated: residences interviewed, interviewed residences with eligible persons, and eligible persons who completed the interview. In addition, an overall index that combined the three components was calculated. The overall response rate ranged from 35.6% in Mexico to 81.4% in Chile. The component with the greatest variability was the participation of eligible persons, which ranged from 50% in Mexico to 95% in Cuba. These values were lower than what had been expected, especially among men, and will serve to guide future surveys, since rejection rates higher than the ones expected in the protocol should be considered. The results make it possible to infer the validity of the prevalence estimates for the various observed risk behaviors. The results also establish a benchmark to calculate the sample size in future surveys and to improve research methodology.