title: Does my patient have chronic Chagas disease? Development and temporal validation of a diagnostic risk score.
abstract: BACKGROUND
  With the globalization of Chagas disease, unexperienced health care providers may have difficulties in identifying which patients should be examined for this condition. This study aimed to develop and validate a diagnostic clinical prediction model for chronic Chagas disease.
  
  
  METHODS
  This diagnostic cohort study included consecutive volunteers suspected to have chronic Chagas disease. The clinical information was blindly compared to serological tests results, and a logistic regression model was fit and validated.
  
  
  RESULTS
  The development cohort included 602 patients, and the validation cohort included 138 patients. The Chagas disease prevalence was 19.9%. Sex, age, referral from blood bank, history of living in a rural area, recognizing the kissing bug, systemic hypertension, number of siblings with Chagas disease, number of relatives with a history of stroke, ECG with low voltage, anterosuperior divisional block, pathologic Q wave, right bundle branch block, and any kind of extrasystole were included in the final model. Calibration and discrimination in the development and validation cohorts (ROC AUC 0.904 and 0.912, respectively) were good. Sensitivity and specificity analyses showed that specificity reaches at least 95% above the predicted 43% risk, while sensitivity is at least 95% below the predicted 7% risk. Net benefit decision curves favor the model across all thresholds.
  
  
  CONCLUSIONS
  A nomogram and an online calculator (available at http://shiny.ipec.fiocruz.br:3838/pedrobrasil/chronic_chagas_disease_prediction/) were developed to aid in individual risk estimation.
authors.affiliation: Laboratório de Pesquisa Clínica em doença de Chagas, Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: Pedro Emmanuel Alvarenga Americano do
authors.initials: PE
authors.lastname: Brasil
authors.affiliation: Laboratório de Pesquisa Clínica em doença de Chagas, Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: Sergio Salles
authors.initials: SS
authors.lastname: Xavier
authors.affiliation: Laboratório de Pesquisa Clínica em doença de Chagas, Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: Marcelo Teixeira
authors.initials: MT
authors.lastname: Holanda
authors.affiliation: Laboratório de Pesquisa Clínica em doença de Chagas, Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: Alejandro Marcel
authors.initials: AM
authors.lastname: Hasslocher-Moreno
authors.affiliation: Departamento de Epidemiologia e Métodos Quantitativos em Saúde, Escola Nacional de Saúde Pública, Fundação Oswaldo Cruz, Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: José Ueleres
authors.initials: JU
authors.lastname: Braga
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014355:Chagas Disease / Q000175:diagnosis*; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D020379:Risk Adjustment; D012680:Sensitivity and Specificity; D055815:Young Adult