A reação em cadeia por polimerase (PCR) e suas variantes tem sido, desde o isolamento do metapneumovírus humano (hMPV), a técnica mais utilizada para a detecção do vírus em secreções respiratórias de diferentes grupos de pacientes. Entretanto, a interpretação de estudos abordando aspectos epidemiológicos e patogenéticos da infecção pelo hMPV tem sido dificultada pelo uso de uma grande variedade de técnicas de PCR \"in house\" na ausência de uma técnica \"padrão ouro\" claramente definida. A avaliação da sensibilidade, especificidade e reprodutibilidade de qualquer técnica molecular \"in house\" é um passo crucial para podermos comparar estudos realizados por diferentes grupos de pesquisa e diferentes grupos de pacientes. Este estudo teve como objetivos a padronização de duas técnicas de PCR - convencional e em tempo real - para a detecção do hMPV em secreções respiratórias e a avaliação da concordância existente entre as técnicas. Entre 228 amostras de lavado de nasofaringe coletadas de receptores de transplante de células tronco hematopoiéticas com sintomas de infecção respiratória aguda, 10 (4,4%) foram positivas para a presença do hMPV pela técnica de PCR convencional enquanto que 11 (4,8%) foram positivas pela técnica de PCR em tempo real. A concordância entre as técnicas, medida pelo índice Kappa para um intervalo de confiança de 95%, foi de 0,95, ou seja, quase perfeita. / The polymerase chain reaction (PCR) has been, since the isolation of the virus in 2001, the most used technique for detection of human metapneumovirus (hMPV) in respiratory specimens of several groups of patients. However, the interpretation of studies regarding the epidemiology and pathogenesis of hMPV infection has been hindered by the use of a great variety of PCRs techniques for hMPV detection, in the absence of a clearly defined \"gold standard\". The assessment of the sensitivity, specificity and reproducibility of any in-house molecular technique is a crucial step to allow the comparison of studies conducted in different settings and different groups of patients. The aim of the present study was to standardize two in-house PCR assays a conventional PCR and a real-time PCR for detecting hMPV in nasopharyngeal aspirates and to evaluate the agreement between the two assays. Of 228 samples of nasopharyngeal aspirates obtained from hematopoietic stem cell transplant recipients with acute respiratory symptoms, 10 (4.4%) were positive for hMPV by conventional PCR whereas 11 (4.8%) were positive by real-Time PCR. The agreement of both assays, measured by Kappa Index, was almost perfect (0.95, 95% confidence interval).

Since the Institute of Medicine highlighted the devastating impact of medical errors in their seminal report, “To Err is Human” (2000), efforts have been underway to improve patient safety. A portion of medical errors are due to medication errors, and a large portion of these can be attributed to inadequate laboratory monitoring. In this thesis, I attempt to address this small but important corner of this patient safety endeavor. Why are patients not getting their laboratory monitoring tests? Do they fail to complete them or do doctors not order the tests in the first place? Which prescribers and which patients are least likely to do what is needed for testing to happen and what interventions would be most promising? To address these questions, I conducted a systematic review of existing interventions. I then proceeded with three aims: 1) To identify reasons that patients give for missing monitoring tests; 2) To identify patient and provider factors associated with monitoring test ordering; and 3) To identify patient and provider factors associated with completion of ordered testing. To achieve these aims, I worked with patients and data at the Fallon Clinic. For aim 1, I conducted a qualitative analysis of their reasons for missing tests as well as reporting completion and ordering rates. For aims 2 and 3, I used electronic medical record data and conducted a regression with patient and provider characteristics as covariates to identify factors contributing to test ordering and completion. Interviews revealed that patients had few barriers to completion, with forgetting being the most common reason for missing a test. The quantitative studies showed that: older patients with more interactions with the health care system were more likely to have tests ordered and were more likely to complete them; providers who more frequently prescribe a drug were more likely to order testing for it; and drug-test combinations that were particularly dangerous, indicated by a black box warning, were more likely to have appropriate ordering, though for these combinations, primary care providers were less likely to order tests appropriately, and patients were less likely to complete tests. Taken together, my work can inform future interventions in laboratory monitoring and patient safety.

O Laboratório de Análises Clínicas (LAC) vem buscando, no decorrer dos anos, alternativas quanto à sua capacidade em gerar receita. A busca por melhores resultados incrementou a parceria com as organizações chamadas de \"convênios médicos\" ou \"medicina de grupo\" que, em geral, remuneram as análises laboratoriais com base em tabelas de procedimentos criadas pela Associação Médica Brasileira AMB. Destas, a mais utilizada é a Tabela AMB 92, devido a utilizar valores de Coeficiente de Honorários (CH), que convertidos em reais, são mais interessantes para os LAC. Este estudo teve como base o método recomendado pelo \"National Committee for Clinical Laboratory Standards\" - NCCLS, que normatiza a apuração do custo baseado na atividade desempenhada durante a sua realização. O objetivo deste trabalho foi estabelecer o custo das análises laboratoriais e verificar se, em comparação à tabela AMB 92, a opção pelos contratos com os \"convênios médicos\" realmente gera lucro a um laboratório de pequeno porte. Para tanto foram selecionadas as análises mais solicitadas no mês de agosto de 2004 em um laboratório de pequeno porte, que presta atendimento a pacientes conveniados a planos de saúde e particulares. O ressarcimento aos laboratórios prestadores de serviço é efetuado com base no valor do CH, que pode variar de acordo com o contrato firmado com os convênios médicos. Os resultados mostraram que na comparação dos custos unitários das 69 análises apuradas com a Tabela AMB-92 houve lucro em 52% das análises quando o valor de CH foi de R$ 0,2610 e quando atribuído um valor de CH de R$ 0,1800, houve lucro em apenas 28% das análises. / The Clinical Laboratory (CL) has been seeking, throughout these years, alternative forms of increasing budget. The search for better results has flourished partnerships with organizations named \"prepaid group practice\" or \"group medicine\" which usually reward the clinical analysis based on tables of procedures established by the Brazilian Medicai Association - BMA. Among them, the most employed is the BMA 92 Table, due to the use of payment coefficient values (PC) which, expressed in Brazilian currency (reais), are in CLs interests. This study was carried out based on the method recommended by the National Committee for Clinical Laboratory Standards - NCCLS, who draws up the regulation of the cost estimate of a procedure while it is carried out. The objective of this study was to establish the cost of clinical analysis and to verify if, comparing to the BMA 92 Table, the contracts with prepaid group practices are actually profitable for a small size laboratory. In order to achieve it, most requested analysis during August 2004 in a small size laboratory which offers services to patients affiliated with prepaid health plans and private health plans. The payment to the laboratories which offer services is made regarding the PC values, which may change according to the contract with the health plans. The results demonstrated that in comparison to the cost of each one of 69 analysis verified according to the BMA 92 Table, 52% of the analysis were profitable when the PC value was R$ 0.2610 and for the PC value of R$ 0.1800 only 28% of the analysis were profitable.

O Laboratório de Análises Clínicas (LAC) vem buscando, no decorrer dos anos, alternativas quanto à sua capacidade em gerar receita. A busca por melhores resultados incrementou a parceria com as organizações chamadas de \"convênios médicos\" ou \"medicina de grupo\" que, em geral, remuneram as análises laboratoriais com base em tabelas de procedimentos criadas pela Associação Médica Brasileira AMB. Destas, a mais utilizada é a Tabela AMB 92, devido a utilizar valores de Coeficiente de Honorários (CH), que convertidos em reais, são mais interessantes para os LAC. Este estudo teve como base o método recomendado pelo \"National Committee for Clinical Laboratory Standards\" - NCCLS, que normatiza a apuração do custo baseado na atividade desempenhada durante a sua realização. O objetivo deste trabalho foi estabelecer o custo das análises laboratoriais e verificar se, em comparação à tabela AMB 92, a opção pelos contratos com os \"convênios médicos\" realmente gera lucro a um laboratório de pequeno porte. Para tanto foram selecionadas as análises mais solicitadas no mês de agosto de 2004 em um laboratório de pequeno porte, que presta atendimento a pacientes conveniados a planos de saúde e particulares. O ressarcimento aos laboratórios prestadores de serviço é efetuado com base no valor do CH, que pode variar de acordo com o contrato firmado com os convênios médicos. Os resultados mostraram que na comparação dos custos unitários das 69 análises apuradas com a Tabela AMB-92 houve lucro em 52% das análises quando o valor de CH foi de R$ 0,2610 e quando atribuído um valor de CH de R$ 0,1800, houve lucro em apenas 28% das análises. / The Clinical Laboratory (CL) has been seeking, throughout these years, alternative forms of increasing budget. The search for better results has flourished partnerships with organizations named \"prepaid group practice\" or \"group medicine\" which usually reward the clinical analysis based on tables of procedures established by the Brazilian Medicai Association - BMA. Among them, the most employed is the BMA 92 Table, due to the use of payment coefficient values (PC) which, expressed in Brazilian currency (reais), are in CLs interests. This study was carried out based on the method recommended by the National Committee for Clinical Laboratory Standards - NCCLS, who draws up the regulation of the cost estimate of a procedure while it is carried out. The objective of this study was to establish the cost of clinical analysis and to verify if, comparing to the BMA 92 Table, the contracts with prepaid group practices are actually profitable for a small size laboratory. In order to achieve it, most requested analysis during August 2004 in a small size laboratory which offers services to patients affiliated with prepaid health plans and private health plans. The payment to the laboratories which offer services is made regarding the PC values, which may change according to the contract with the health plans. The results demonstrated that in comparison to the cost of each one of 69 analysis verified according to the BMA 92 Table, 52% of the analysis were profitable when the PC value was R$ 0.2610 and for the PC value of R$ 0.1800 only 28% of the analysis were profitable.

Introduction – La place des tests de diagnostic rapide (TDR) et des règles de décision cliniques (RDC) pour le diagnostic des pharyngites à streptocoque du groupe A (SGA) chez l’enfant varie selon les recommandations internationales en raison de doutes sur la stabilité des performances diagnostiques du TDR et d’une validation insuffisante des RDC. Méthodes – Dans une étude prospective multicentrique (n=17) ambulatoire réalisée au sein du réseau clinique pédiatrique ACTIV de 2009 à 2011, 1776 enfants avec pharyngite ou sains ont été soumis à des prélèvements de gorge pour réaliser un TDR et une mise en culture (test de référence). Nous avons étudié l’effet indépendant de variables liées aux patients et aux médecins sur les performances diagnostiques du TDR, exploré systématiquement les faux-Positifs (FP) du TDR et réalisé une validation externe et une comparaison des RDC existantes. Résultats – La sensibilité du TDR (en moyenne 87%) variait selon la présentation clinique (âge, signes cliniques), l’inoculum bactérien et le phénomène de portage (paramètres aussi liés entre eux), et selon des variables liées aux médecins (dont le type d’activité clinique). La valeur prédictive négative du TDR était élevée (autour de 90%) et stable. Les FP du TDR étaient positifs pour le SGA en PCR. Aucune RDC n’était satisfaisante en termes de calibration et de discrimination. Conclusion – Le TDR est suffisant pour le diagnostic de pharyngite à SGA si les cliniciens évaluent leurs propres performances et les améliorent si besoin. Aucune RDC ne peut être recommandée en pratique clinique en pédiatrie. / Background – The roles of rapid antigen detection tests (RADT) and clinical prediction rules (CPR) for the diagnosis of group A streptococcus (GAS) in children with pharyngitis vary across international clinical guidelines. This might be related to unstable diagnostic accuracy of RADTs and insufficient validation of CPRs. Methods – In a prospective multicenter (n=17) office-Based study that took place in France within the ACTIV network between 2009 and 2011, 1776 children with pharyngitis or healthy controls underwent throat swabs to perform a RADT and a throat culture (reference standard). We assessed the independent effect of patient- and physician-Level characteristics on the accuracy of a RADT, systematically re-Analyzed RADT false-Positive results, and externally validated and compared existing CPRs. Results – RADT sensitivity (overall 87%) varied according to clinical signs and symptoms, bacterial inoculum size and GAS throat carriage (factors also related to each other), and according to physician-Level characteristics (including type of clinical practice). RADT negative predictive value was high (about 90%) and stable. RADT false-Positives were positive for GAS when using a new PCR technique. No CPR had sufficient performances regarding calibration and discrimination. Conclusions – RADTs are sufficient for diagnosing GAS pharyngitis if clinicians accept diagnostic accuracy monitoring and adequate training when needed. No CPR can be recommended for use in pediatrics.

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This thesis addresses the three principal questions concerning the development of CT urography for investigating haematuria and each question is the subject of a separate chapter. The questions are: What is the reasoning behind using CT urography? What is the optimum diagnostic strategy using CT urography? What are the problems with using CT urography and how may solutions be provided? Haematuria can signify serious disease such as urinary tract stones, renal cell cancer, upper tract urothelial cancer (UTUC) and bladder cancer (BCa). CT urography is defined as contrast enhanced CT examination of kidneys, ureters and bladder. The technique used here includes unenhanced, nephrographic and excretory-phases for optimized diagnosis of stones, renal masses and urothelial cancer respectively. The reasoning behind using excretory-phase CT urography for investigating haematuria is based on results showing its high diagnostic accuracy for UTUC and BCa. Patients with haematuria are classified as low risk or high risk for UTUC and BCa, by a risk score, determined by the presence/absence of risk factors: age > 50 years, visible or nonvisible haematuria, history of smoking and occupational exposure. The optimum diagnostic strategy for patients at high risk for urothelial cancer, uses CT urography as a replacement test for ultrasonography and intravenous urography and as a triage test for flexible and rigid cystoscopy, resulting in earlier diagnosis and potentially improving prognosis. For patients at low risk, ultrasonography, unenhanced and nephrographic-phase CT urography are proposed as initial imaging tests. Problems with using CT urography include false positive results for UTUC, which are eliminated by retrograde ureteropyelography-guided biopsy, an innovative technique, for histopathological confirmation of diagnosis. Recommendations for the NHS and possible future developments are discussed. CT urography, including excretory-phase imaging, is recommended as the initial diagnostic imaging test before cystoscopy for patients with haematuria at high risk for urothelial cancer.