ABSTRACT
Abstract: Brazil has the second largest number of leprosy cases (a disease with a significant burden) in the world. Despite global and local efforts to eliminate this public health problem, inadequate or late diagnosis contribute to perpetuate its transmission, especially among household contacts. Tests such as the rapid IgM antibody detection (RT) and real-time polymerase chain reaction (RT-PCR) were developed to overcome the challenges of early diagnosis of leprosy. This study aimed to analyze the cost-effectiveness of a new diagnostic algorithm recommended by the Brazilian government to diagnose leprosy in household contacts of confirmed leprosy cases, which includes the RT and RT-PCR tests. A decision tree model was constructed and the perspective of the Brazilian Unified National Health System (SUS) and a 1-year time horizon were adopted. Only direct medical costs related to diagnostic tests were included. Effectiveness was measured as the number of avoided undiagnosed leprosy cases. Different scenarios were analyzed. The sequential use of RT, slit-skin smear (SSS) microscopy, and RT-PCR as recommended by the Brazilian Ministry of Health was compared to a base case (isolated SSS microscopy), yielding an incremental cost-effectiveness ratio of USD 616.46 per avoided undiagnosed leprosy case. Univariate sensitivity analysis showed that the prevalence of leprosy among household contacts was the variable that influenced the model the most. This is the first economic model to analyze a diagnostic algorithm of leprosy. Results may aid managers to define policies and strategies to eradicate leprosy in Brazil.
Resumo: O Brasil tem o segundo maior número de casos de hanseníase (doença com carga significativa) do mundo. Apesar dos esforços globais e locais para eliminar esse problema de saúde pública, o diagnóstico inadequado ou tardio contribui para perpetuar sua transmissão, especialmente entre contatos intradomiciliares. Exames como o teste rápido de anticorpos IgM (RT) e a reação em cadeia da polimerase em tempo real (RT-PCR) foram desenvolvidos para superar as barreiras do diagnóstico precoce da hanseníase. Este estudo teve como objetivo analisar a relação custo-efetividade de um novo algoritmo de diagnóstico recomendado pelo governo brasileiro para diagnosticar a hanseníase em contatos domiciliares de casos confirmados de hanseníase, que inclui os testes RT e RT-PCR. Foi construído um modelo de árvore de decisão e adotada a perspectiva do Sistema Único de Saúde (SUS) considerando o período de um ano. Foram incluídos apenas os custos médicos diretos relacionados aos exames diagnósticos. A efetividade foi medida considerando o número de casos evitados de hanseníase. Diferentes cenários foram analisados. O uso sequencial de RT, baciloscopia e RT-PCR, conforme recomendado pelo Ministério da Saúde, foi comparado a um caso base (baciloscopia isolada), obtendo-se uma razão de custo-efetividade incremental de USD 616,46 por caso evitado de hanseníase. A análise de sensibilidade univariada mostrou que a prevalência de hanseníase entre contatos intradomiciliares foi a variável que mais influenciou o modelo. Este é o primeiro modelo econômico a analisar um algoritmo diagnóstico da hanseníase. Os resultados poderão auxiliar os gestores na definição de políticas e estratégias para a erradicação da hanseníase no Brasil.
Resumen: Brasil tiene el segundo mayor número de casos de lepra (enfermedad con carga significativa) del mundo. A pesar de los esfuerzos globales y locales para eliminar ese problema de salud pública, el diagnóstico inadecuado o tardío contribuye a perpetuar su transmisión, sobre todo entre contactos intradomiciliarios. Los exámenes como la prueba rápida de anticuerpos IgM (RT) y la reacción en cadena de la polimerasa en tiempo real (RT-PCR) se desarrollaron para superar las barreras del diagnóstico precoz de la lepra. El objetivo de este estudio fue analizar la relación de costo-efectividad de un nuevo algoritmo de diagnóstico recomendado por el gobierno brasileño para diagnosticar la lepra en contactos domiciliarios de casos confirmados de lepra, que incluye las pruebas RT y RT-PCR. Se construyó un modelo de árbol de decisión y se adoptó la perspectiva del Sistema Único de Salud (SUS) teniendo en cuenta el periodo de un año. Solo se incluyeron los costos médicos directos relacionados con los exámenes diagnósticos. Se midió la efectividad teniendo en cuenta el número de casos de lepra evitados. Se analizaron distintos escenarios. Se comparó el uso secuencial de RT, baciloscopia y RT-PCR, conforme el Ministerio de Salud recomienda, con un caso base (baciloscopia aislada), y se obtuvo un cociente de costo-efectividad incremental de USD 616,46 por cada caso de lepra evitado. El análisis de sensibilidad univariante mostró que la prevalencia de lepra entre contactos intradomiciliarios fue la variable que más influyó el modelo. Este es el primer modelo económico que analiza un algoritmo diagnóstico de lepra. Los resultados podrán ayudar los gestores a definir políticas y estrategias para erradicar la lepra en Brasil.
ABSTRACT
Abstract Since the early 20th century, the detection of intestinal parasites has improved with the development of several techniques for parasitic structures recovery and identification, which differ in sensitivity, specificity, practicality, cost, and infrastructure demand. This study aims to review, in chronological order, the stool examination techniques and discuss their advantages, limitations, and perspectives, and to provide professionals and specialists in this field with data that lays a foundation for critical analysis on the use of such procedures. The concentration procedures that constitute the main techniques applied in routine research and in parasitological kits are a) spontaneous sedimentation; b) centrifugation-sedimentation with formalin-ethyl acetate; and c) flotation with zinc sulfate solution. While selecting a technique, one should consider the purpose of its application and the technical-operational, biological, and physicochemical factors inherent in the procedures used in stool processing, which may restrict its use. These intrinsic limitations may have undergone procedural changes driven by scientific and technological development and by development of alternative methods, which now contribute to the improvement of diagnostic accuracy.
Subject(s)
Humans , Animals , History, 20th Century , History, 21st Century , Parasitology/history , Specimen Handling/history , Feces/parasitology , Intestinal Diseases, Parasitic/diagnosis , Parasitology/methods , Specimen Handling/methods , Sensitivity and SpecificityABSTRACT
Objective To investigate the implementation of professional standards for reference intervals in routine biochemistry laboratories.Methods The relevant data of reference intervals from different laboratories including upper and lower limits,sources of reference intervals,verification and grouping rules,etc was submitted by using the software of interval quality assessment (EQA) via WEB application.The background monitor saved all the data as Microsoft Excel 2007 documents.The implementation of reference intervals of professional standards for decreed 18 routine biochemical tests was analyzed.Results The proportion of laboratories in which the reference intervals were derived from professional standards increased largely in 2016 compared with those in 2014.The data of 2016 showed that the reference intervals derived from professional standards were verified in 58.9％ to 67.5％ of laboratories before they were used in clinical diagnosis.The grouping rules for reference intervals in most laboratories (59.1％ to 83.3％) were in accordance with professional standards,except for individual items,including urea (43.4％),creatinine (40.1％) and alkaline phosphatase (35.8％).There were significant differences for the upper and lower limits of the most items between the laboratories using professional standards and those without using professional standards (P ＜ 0.05),except for some items,including lower limit value of kalium,upper limit of phosphorus,upper limit of amylase,upper limit of aspartate aminotransferase and lower limit of ferrum.There was no significant difference in most items between the the upper and lower limits of the reference intervals in the laboratories using professional standards and the reference intervals defined by professional standards,except for individual items,including upper limit of total protein,lower and upper limit of creatine kinase,upper limit of urea and upper limit of creatinine (P ＜ 0.05).Conclusion The implementation of reference intervals from professional standards in most routine biochemistry laboratories could not be satisfactory.Only a small part of laboratories used the professional standards,and the reference intervals of professional standards,were not verified before use in quite a part of laboratories.