Loop-mediated isothermal DNA amplification (LAMP) are currently used as standalone diagnostic test for C. difficile infection (CDI). We assessed the diagnostic accuracy of LAMP for the diagnosis of CDI. We searched 5 databases to identify studies that compared LAMP with culture cytotoxicity neutralization assay or anaerobic toxigenic culture (TC) of C. difficile. We used the random-effects model to calculate pooled sensitivities, specificities, diagnostic odds ratios and their 95% confidence intervals (CIs). The search of the databases yielded 16 studies (6,979 samples) that met inclusion criteria. When TC was used as the gold standard (6,572 samples), bivariate analysis yielded a mean sensitivity of 0.95 (95%CI, 0.93-0.97; I2 = 67.4) and a mean specificity of 0.99 (95%CI, 0.96-1.00; I2 = 97.0). LAMP is a useful diagnostic tool with high sensitivity and specificity for detecting CDI. The results should however be interpreted only in the presence of clinical suspicion and symptoms of CDI. / Revisión por pares

This thesis presents the results of three complementary studies which were carried out to evaluate the accuracy of diagnostic tests for Salmonella in pigs. First, a research synthesis method approach, which included a systematic review, meta-analysis and meta-regression, was used to map out existing primary research investigating the accuracy of bacterial culture, antibody or antigen -capture ELISA, and PCR for Salmonella in pigs under field conditions.. Large statistical variability, limited methodological soundness and reporting precluded a quantitative synthesis of findings from multiple studies. The meta-regression identified significant factors, such as variations in test protocols, which explained much of the variability of reported estimates of test accuracy. The need for consistent use of a standard reference test is essential to ensure comparability of results generated in future studies.<p> In the second study, the accuracy of a bacterial culture, real-time (RT) PCR, and a mix-ELISA for Salmonella in were evaluated in western Canadian nursery and grow-finish pigs using traditional and Bayesian statistical methods. Ten farrow-to-finish pig farms from Alberta and Saskatchewan were purposively selected based on their presumptive Salmonella status. Bacteriological culture, RT-PCR and a mix-ELISA were performed on feces and blood samples collected from grow-finish (n=294) pigs and pens. Bayesian estimates of test sensitivity (Se) and specificity (Sp) at the individual pig level were similar to traditional statistical estimates. Sensitivity of culture and RT-PCR ranged from 65-75%, PCR Sp was 98-99% and ELISA Se and Sp at a cutoff of OD¡Ý20% ranged from 59-63% and 84-87%, respectively. In the third study, Salmonella serovar distribution and risk factors for Salmonella shedding were investigated in breeding, nursery, and grow-finish pigs using the same 10 herds. Among 418 Salmonella isolates, most common serovars were Derby (28.5%), Typhimurium, var. Copenhagen (19.1%), and Putten (11.8%). More Salmonella were detected in pooled pen than individual pig samples, confirming that the use of pooled samples is more effective for detecting the full range of serovars that may be present on Canadian pig farms. Sows shed significantly more Salmonella than nursery or grow to finish pigs, suggesting that the breeding herd is an important source of Salmonella persistence. Pelleted feed and nose-to-nose pig contact through pens were also associated with increased Salmonella prevalence, indicating that these factors are relevant as control targets.<p> The main advantages of research synthesis methods are increased power and precision in effect estimates and identification knowledge gaps and areas requiring further research. Bayesian methods for evaluating test accuracy are useful when there is no known "gold standard", which is often the case for zoonotic and food-borne pathogens. Both research synthesis and Bayesian methods are valuable tools for evaluating diagnostic test accuracy and should be more frequently used when developing monitoring and control programs in food safety.

This thesis presents the results of three complementary studies which were carried out to evaluate the accuracy of diagnostic tests for Salmonella in pigs. First, a research synthesis method approach, which included a systematic review, meta-analysis and meta-regression, was used to map out existing primary research investigating the accuracy of bacterial culture, antibody or antigen -capture ELISA, and PCR for Salmonella in pigs under field conditions.. Large statistical variability, limited methodological soundness and reporting precluded a quantitative synthesis of findings from multiple studies. The meta-regression identified significant factors, such as variations in test protocols, which explained much of the variability of reported estimates of test accuracy. The need for consistent use of a standard reference test is essential to ensure comparability of results generated in future studies.<p> In the second study, the accuracy of a bacterial culture, real-time (RT) PCR, and a mix-ELISA for Salmonella in were evaluated in western Canadian nursery and grow-finish pigs using traditional and Bayesian statistical methods. Ten farrow-to-finish pig farms from Alberta and Saskatchewan were purposively selected based on their presumptive Salmonella status. Bacteriological culture, RT-PCR and a mix-ELISA were performed on feces and blood samples collected from grow-finish (n=294) pigs and pens. Bayesian estimates of test sensitivity (Se) and specificity (Sp) at the individual pig level were similar to traditional statistical estimates. Sensitivity of culture and RT-PCR ranged from 65-75%, PCR Sp was 98-99% and ELISA Se and Sp at a cutoff of OD¡Ý20% ranged from 59-63% and 84-87%, respectively. In the third study, Salmonella serovar distribution and risk factors for Salmonella shedding were investigated in breeding, nursery, and grow-finish pigs using the same 10 herds. Among 418 Salmonella isolates, most common serovars were Derby (28.5%), Typhimurium, var. Copenhagen (19.1%), and Putten (11.8%). More Salmonella were detected in pooled pen than individual pig samples, confirming that the use of pooled samples is more effective for detecting the full range of serovars that may be present on Canadian pig farms. Sows shed significantly more Salmonella than nursery or grow to finish pigs, suggesting that the breeding herd is an important source of Salmonella persistence. Pelleted feed and nose-to-nose pig contact through pens were also associated with increased Salmonella prevalence, indicating that these factors are relevant as control targets.<p> The main advantages of research synthesis methods are increased power and precision in effect estimates and identification knowledge gaps and areas requiring further research. Bayesian methods for evaluating test accuracy are useful when there is no known "gold standard", which is often the case for zoonotic and food-borne pathogens. Both research synthesis and Bayesian methods are valuable tools for evaluating diagnostic test accuracy and should be more frequently used when developing monitoring and control programs in food safety.

Revisión por pares

>Magister Scientiae - MSc / Periapical lesions are fairly common pathology associated with the apex of a non-vital tooth. Some chronic lesions develop without an acute phase with no recollection of previous symptoms. It is known that maxillary odontogenic infections can breach the sinus floor with succeeding complications. Pantomography, a widespread conventional radiographic technique, provides a generalized view of the maxillofacial region. Advanced modalities like CBCT may facilitate in navigating complex anatomy, which would otherwise be obscured.

No description available.

OBJETIVO: Avaliar a relação entre mensurações de gordura (subcutânea e periprostática) realizadas em ressonância magnética, com o prognóstico do paciente portador de câncer de próstata. MATERIAIS E MÉTODOS: A mensuração da gordura periprostática e subcutânea com exame de ressonância magnética com ênfase na próstata foram realizadas em 58 pacientes com o diagnóstico histopatológico de câncer de próstata. Dados demográficos, clínicos e patológicos dos pacientes foram coletados e a correlação com o prognóstico, realizada. RESULTADOS: Na análise univariada, as gorduras periprostática e a subcutânea indicaram serem preditores de evolução desfavorável com significância estatística para o observador 1, no caso da gordura periprostática e para o observador 2 no caso da gordura subcutânea. Na análise multivariada, não houve associação com significância estatística. CONCLUSÃO: A associação entre obesidade e o câncer de próstata é complexa. Os dados obtidos neste estudo indicam que a medida da gordura periprostática, pelas imagens em T2, na RM, podem ser um preditor independente, da evolução desfavorável de pacientes com neoplasia de próstata / PURPOSE: Evaluate the relationship between fat measurements (subcutaneous and periprostatic) performed on MRI, with the prognosis of the patient with prostate cancer. MATERIALS AND METHODS: Measurements of periprostatic and subcutaneous fat with magnetic resonance imaging with emphasis on the prostate were performed in 58 patients with the histopathological diagnosis of prostate cancer. Demographic, clinical and pathological data of the patients were collected and the correlation with the prognosis was performed. RESULTS: In the univariate analysis, the periprostatic and subcutaneous fat were predictors of unfavorable evolution with statistical significance for the observer 1, in the case of the periprostatic fat and for the observer 2 in the case of the subcutaneous fat. In the multivariate analysis, there was no association with statistical significance. CONCLUSION: The association between obesity and prostate cancer is complex. The data obtained in this study indicate that the measurement of periprostatic fat by T2-weighted images in MRI may be an independent predictor of the unfavorable evolution of patients with prostate neoplasia

Background Pain and dysfunction in the temporomandibular region (Temporomandibular Disorders, TMD) are common conditions in the general population with an estimated treatment need of 5-15% in the general population. However, in Sweden, traceable performed treatments are significantly lower. The reasons for this indicated under-treatment are not known. To easily detect patients with a potential TMD related condition, three screening questions, 3Q/TMD, have been introduced. The aim with this project was to evaluate the validity and outcome of the 3Q/TMD with the objective to recognize individuals with TMD and potential treatment need in the Public Dental Health service (PDHS). Methods The thesis is based on four study samples; three from the PDHS in the county of Västerbotten, Sweden and one sample from the specialized orofacial pain clinic at the Academic Centre for Dentistry, ACTA, Amsterdam, the Netherlands. The bases for all studies are individuals’ answers to the 3Q/TMD and quantitative approaches were used in the analyses. The prevalence of affirmative answers was evaluated in a large cross-sectional study over the lifespan. The validity of the 3Q/TMD in relation to the Diagnostic Criteria for TMD (DC/TMD) as reference standard was established in two case-control studies. The outcome of the 3Q/TMD on TMD treatment within general practice was evaluated in a cohort study. Results Affirmative answers to the 3Q/TMD increased during adolescence. Women answered affirmatively to the 3Q/TMD significantly more often compared to men for all age groups expect for the first and last parts of a one hundred-year lifespan. The highest prevalence was reported by women during their fertile period in life. In a general population sample, 74% of individuals with an affirmative answer qualified for a DC/TMD pain or dysfunctional diagnosis, as compared to 64% in a specialist patient sample. In the general population sample, for the individual 3Q/TMD questions, as well as combinations of questions, the negative predictive values were high (0.92-0.99). For the specialist sample, when at least one question was answered affirmatively the negative predictive value was high (0.90). The positive predictive value was high (0.89) when all three questions were positive. There was significantly more treatment performed or recommended for 3Q-positives (21.5%) compared to 3Q-negatives (2.2%) (P&lt;0.001). The odds ratio for TMD-related treatment for 3Q-positives versus 3Q-negatives was 12.1 (95% CI: 6.3-23.4). Conclusion The 3Q/TMD is a convenient and valid tool to recognize individuals who would benefit from a further TMD examination within an adult, general population. Within specialized orofacial pain clinics, the questions are useful as guidance for further diagnostics. Although the 3Q/TMD was a factor related to TMD treatment, the majority of individuals with self-reported symptoms of TMD still did not receive traceable assessment or treatment. Factors associated with dentists’ clinical decision-making in relation to TMD warrants further research. The utilization of the 3Q/TMD as a part of a decision tree for the clinician can improve the health care for patients with TMD and is therefore recommended within dentistry. / Bakgrund Smärta och funktionsstörningar i käksystemet (TMD) är vanligt förekommande och de flesta av dessa patienter kan behandlas framgångsrikt i tandvården. Tidigare studier har visat att det kan finnas en skillnad mellan det skattade vårdbehovet och utförd behandling för patienter med TMD i tandvården. Anledningen till detta är inte känt och har identifierats som en kunskapslucka av Socialstyrelsen. Den vanligaste orsaken till akut smärta i ansiktsregion är tandvärk medan kronisk smärta oftast är relaterat till smärttillstånd i muskulatur och käkled (TMD). Att leva med smärta har en negativ påverkan på livskvaliteten oavsett om smärtan är orsakad av tandvärk eller TMD. Kvinnor uppger symtom på TMD ungefär två gånger så ofta som män och förekomsten är som högst bland kvinnor i arbetsför ålder. Smärtan är ofta relaterad till stress och långvarig smärta ökar risken för såväl spridning till andra lokalisationer som till sömnbesvär och nedstämdhet. Tidig intervention har visat sig betydelsefull för att minska risken för negativa konsekvenser relaterat till kroniska besvär. Sammantaget visar detta på vikten av ett system inom tandvården för att tidigt identifiera patienter som är i möjligt behov av fördjupad utredning och eventuellt behandling. Därför har tre screeningfrågor för TMD, 3Q/TMD införts inom tandvården. I Folktandvården i Västerbotten infördes frågorna i maj 2010 som en obligatorisk del av den digitala hälsodeklarationen för samtliga patienter. Syfte Syftet med avhandlingen har varit att synliggöra patienter med smärta och käkfunktionsstörning i befolkningen och att därmed förbättra omhändertagandet av patienter med TMD inom Folktandvården. De specifika målen var att: i) beskriva förekomst av frekvent smärta och dysfunktion i ansikte, käke och käkled för män och kvinnor för olika åldersgrupper baserat på tre screeningfrågor ii) bedöma de tre screeningfrågornas validitet i förhållande till en diagnos enligt Diagnostic Criteria for TMD, DC/TMD i två olika populationer iii) utvärdera utfallet av 3Q/TMD på klinisk beslutsprocess inom Folktandvården i Västerbotten, Sverige. Studiepopulation och metod Avhandlingen baserades på fyra olika urval av patientpopulationer, tre från Folktandvården i Västerbotten, Sverige och en från Specialistkliniken från Academish Centrum Tandheelkunde Amsterdam, ACTA, Amsterdam, Nederländerna. Underlaget för samtliga studier var baserade på individuella svar på de tre screeningfrågorna. Förekomsten av de som svarat ja på någon av frågorna utvärderades i en tvärsnittsstudie bland nästan 140 000 individer och över ett helt livsspann. Validiteten för 3Q/TMD i relation till en diagnos enligt DC/TMD utvärderades i två fall-kontroll studier. Först undersöktes en studiepopulation från Folktandvården i Västerbotten, Sverige för att representera allmän befolkningen. Därefter utvärderades screeningfrågorna bland de patienter som remitterats till en specialistklinik i Amsterdam, Nederländerna på grund av TMD relaterade besvär. Dessa representerar remitterade patienter. Utfallet av 3Q/TMD på TMD behandling i Folktandvården utvärderades i en prospektiv kohort studie. Resultat Förekomsten av de som svarat ja på någon av frågorna ökar under tonåren. Kvinnor svarar ja på någon av frågorna signifikant oftare än män i alla åldrar, utom i början och slutet av livsspannet. Den högsta prevalensen noterades för kvinnor i fertil ålder. I allmänbefolkningen kvalificerar 74% av de som svarat ja på någon av frågorna även för en DC/TMD diagnos. Motsvarande siffra för urvalet från specialistkliniken var 64%. I urvalet från allmänbefolkningen var det negativa prediktiva värdet högt för såväl alla enskilda frågor som för kombinationer av frågor (0.92-0.99). Bland de remitterade patienterna, var negativt prediktivt värde högt när individen svarade ja på minst en fråga (0.90). Positivt prediktivt värde var högt när individen svarat ja på alla tre frågorna (0.89). Behandling hade utförts eller rekommenderats signifikant oftare till de som svarat ja på någon av frågorna (21.5%) jämfört med de som svarat nej på alla tre frågor (2.2%) (P&lt;0.001). Odds ratio för TMD behandling för 3Q-positiva jämfört med 3Q-negativa var 12.1 (95% CI:6.3-23.4). Slutsats Sammanfattningsvis visar resultaten att en betydande andel av befolkningen, framför allt kvinnor i arbetsför ålder, har smärta och/eller funktionsstörningar i käksystemet. Frågorna är lämpliga för att screena patienter i behov av en fördjupad utredning. De som svarat nej kommer med stor sannolikhet inte att kvalificera för en diagnos enligt DC/TMD. Bland remitterade patienter kommer majoriteten att svara ja på någon av frågorna. I allmäntandvården får två tredjedelar av det som svarat ja på minst en fråga, inte ett synliggjort omhändertagande baserat på vad som är angivet i deras tandvårdsjournal. Detta kan tyda på brister bland allmäntandläkare och tandhygienister i kliniskt beslutsfattande för patienter med TMD.

A constante evolução da tecnologia em saúde permite diagnósticos clínicos cada vez mais rápidos e precisos, porém eles não são isentos de danos. Conhecer e calcular a capacidade preditiva de classificadores de risco é um passo fundamental no desenvolvimento de políticas de saúde e na criação de protocolos clínicos. O processo de avaliação de um teste diagnóstico normalmente tem início com o preenchimento da tabela de contingência. Testes diagnósticos com elevado número de falso positivos geram ansiedade, exames adicionais e tratamentos desnecessários. Testes diagnósticos com elevado número de falso negativos podem contribuir para demoras desnecessárias no tratamento de uma possível doença, podendo dificultar sua cura. A partir da experiência adquirida com a análise da capacidade preditiva do partograma da OMS, esta tese apresenta o desenvolvimento de um novo indicador de capacidade preditiva e diagnóstica de testes. Justifica-se este novo desenvolvimento pela necessidade de simplificar, integralizar e exibir de forma conjunta os principais parâmetros necessários à avaliação da capacidade preditiva e diagnóstica de testes. A avalição dos partogramas de 9.995 mulheres da Nigéria e Uganda mostrou que a linha de alerta deste instrumento possui uma baixa capacidade diagnóstica como preditor para desfechos adversos graves no trabalho de parto. A partir desses e outros resultados, em fevereiro de 2018 a OMS recomendou mudanças no partograma. Com isso, foi explorado o uso do gráfico-radar como uma ferramenta para facilitar a comunicação dos parâmetros já existentes utilizados na avaliação da capacidade diagnóstica dos testes. Sete documentos com diretrizes em saúde materna publicados pela OMS entre os anos de 2016 a 2018 foram utilizados nesse processo. Utilizando o cálculo da área inscrita do gráfico-radar apresenta-se também um novo indicador integrativo para avaliação da capacidade preditiva de testes diagnósticos, o Índice de Máxima Acurácia (IMA) / The constant evolution of health technology allows for faster and more accurate clinical diagnoses, but they are not harmless. Knowing and calculating the predictive capacity of risk classifiers is a fundamental step in the development of health policies and in the creation of clinical protocols. The process of evaluating a diagnostic test usually begins with the completion of the contingency table. Diagnostic tests with high false positives generate avoidable distress, additional tests and unnecessary treatments. Diagnostic tests with high false negatives may contribute to unnecessary delays in the treatment of a possible disease. Based on the experience gained with the analysis of predictive capacity of the WHO partograph, this thesis presents the development of a new indicator of predictive and diagnostic capacity of tests. This new development is justified by the need to simplify, integrate and display together the main parameters necessary for the evaluation of the predictive and diagnostic capacity of tests. The assessment of the partographs of 9,995 women from Nigeria and Uganda showed that the alert line of this instrument has a low diagnostic capacity as a predictor for serious adverse outcomes in labor. From these and other results, in February 2018 the WHO recommended changes in the partograph. The use of the radar chart was explored as a tool to facilitate the communication of the existing parameters used in the evaluation of the diagnostic capacity of the tests. Seven documents with guidelines on maternal health published by WHO between 2016 and 2018 were used in this process. Using the calculated area of the radar chart, a new integrative indicator for the predictive capacity of diagnostic tests, the Index of Maximum Accuracy (IMA), is also presented

Significant research efforts have focused on examining the effect of patient factors on providing diagnoses across clinical settings; however, the influence of clinician demographics have received less attention. This study aimed to understand the impact of nonclinical factors such as clinician characteristics and response time on diagnostic accuracy. The study used data from a WHO field study of the ICD-11 development (n = 1822) that required clinicians to diagnose two case vignettes. Clinicians’ slower response times had a significant positive impact on their rates of diagnostic accuracy. However, there was no evidence that clinicians’ demographic features were directly related to their diagnostic accuracy. Rather, clinicians’ age, years of experience, world region, and their clinical profession indirectly predicted accuracy through their overall response time. Contradictory to decision-making theories, older clinicians and clinicians with more years of experience had higher rates of diagnostic accuracy when they spent more time completing the study. Additionally, clinicians in South America with slower response times had higher accuracy compared to clinicians in North America. Clinicians in Asia had faster response times that negatively impacted their accuracy rates compared to North America clinicians. These findings suggest differences in response time and the applicability of the ICD-11 across cultures. Consistent with previous research, medical professionals with quicker response times had the lowest rates of accuracy compared to psychologists and other clinical professionals. These findings highlight the need for researchers and clinicians to consider the role their dispositional features have in the diagnostic process. Moreover, it is crucial that future research into diagnostic decision-making and accuracy should consider additional mediating factors such as response style, culture, and experience.