Diagnostic accuracy and predictive value in differentiating the severity of dengue infection.

OBJECTIVE: To review the diagnostic test accuracy and predictive value of statistical models in differentiating the severity of dengue infection. METHODS: Electronic searches were conducted in the Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, MEDLINE (complete), PubMed and Scopus. Eligible studies to be included in this review were cohort studies with participants confirmed by laboratory test for dengue infection and comparison among the different severity of dengue infection by using statistical models. The methodological quality of the paper was assessed by independent reviewers using QUADAS-2. RESULTS: Twenty-six studies published from 1994 to 2017 were included. Most diagnostic models produced an accuracy of 75% to 80% except one with 86%. Two models predicting severe dengue according to the WHO 2009 classification have 86% accuracy. Both of these logistic regression models were applied during the first three days of illness, and their sensitivity and specificity were 91-100% and 79.3-86%, respectively. Another model which evaluated the 30-day mortality of dengue infection had an accuracy of 98.5%. CONCLUSION: Although there are several potential predictive or diagnostic models for dengue infection, their limitations could affect their validity. It is recommended that these models be revalidated in other clinical settings and their methods be improved and standardised in future.

OBJECTIF: Analyser la précision des tests de diagnostic et la valeur prédictive des modèles statistiques pour différencier la sévérité de l'infection par la dengue. MÉTHODES: Des recherches électroniques ont été effectuées dans la base de données de revues systématiques Cochrane, le registre central des essais contrôlés Cochrane, MEDLINE (complète), PUBMED et Scopus. Les études éligibles à inclure dans cette revue étaient des études de cohorte avec des participants confirmés par un test de laboratoire pour l'infection par la dengue et une comparaison entre les différentessévérités de l'infection par la dengue à l'aide de modèles statistiques. La qualité méthodologique des articles a été évaluée par des scientifiques indépendants à l'aide de QUADAS-2. RÉSULTATS: 26 études publiées de 1994 à 2017 ont été incluses. La plupart des modèles de diagnostic ont produit une précision de 75% à 80%, sauf un avec 86%. Selon la classification de l'OMS 2009, deux modèles prédisant la dengue sévère présentent une précision de 86%. Ces deux modèles de régression logistique ont été appliqués au cours des trois premiers jours de la maladie. Leur sensibilité et leur spécificité étaient respectivement de 91% à 100% et de 79,3% à 86%. Un autre modèle évaluant la mortalité à 30 jours de la dengue présentait une précision de 98,5%. CONCLUSION: Bien qu'il existe plusieurs modèles prédictifs ou diagnostiques potentiels de l'infection par la dengue, leurs limites pourraient affecter leur validité. Il est recommandé que ces modèles soient revalidées dans d'autres milieux cliniques et leurs méthodes améliorées et normalisées dans le futur.

Routine blood parameters of dengue infected children and adults. A meta-analysis.

The World Health Organization (WHO) has revised dengue case classification in 2009 to better reflect the severity of the disease. However, there was no comprehensive meta-analysis of pooled routine blood parameters according to the age or the categories of the 2009 WHO classification. This study aimed to meta-analyze the routine blood parameters of dengue infected children and adults. Electronic search was performed with eligible articles included for review. Meta-analysis was conducted for six blood parameters stratified into children, adults and all ages, which were further grouped into the three 2009 WHO case classifications (dengue without warning signs, DwoWS; dengue with warning signs, DwWS; severe dengue, SD), non-severe dengue (non-SD) and 'All' cases. A total of 55 articles were included in the meta-analysis. Fifteen studies were conducted in the children's age category, 31 studies in the adult category and nine studies in all ages. The four selected pooled blood parameters for children were white blood cell (WBC) (×103/L) with 5.11 (SD), 5.64 (DwWS), 5.52 (DwoWS) and 4.68 (Non-SD) hematocrit (HCT) (%) with 36.78 (SD), 40.70 (DwWS), 35.00 (DwoWS) and 29.78 (Non-SD) platelet (PLT) (×103/µL) with 78.66 (SD), 108.01 (DwWS), 153.47 (DwoWS) and 108.29 (non-SD); and aspartate aminotransferase (AST) (/µL) with 248.88 (SD), 170.83 (DwWS), 83.24 (DwoWS) and 102.99 (non-SD). For adult, WBC were 4.96 (SD), 6.44 (DwWS), 7.74 (DwoWS) and 3.61 (non-SD); HCT were 39.50 (SD), 39.00 (DwWS), 37.45 (DwoWS) and 41.68 (non-SD); PLT were 49.62 (SD), 96.60 (DwWS), 114.37 (DwoWS) and 71.13 (non-SD); and AST were 399.50 (SD), 141.01 (DwWS), 96.19 (DwoWS) and 118.13 (non-SD). These blood parameters could not differentiate between each dengue severity according to the WHO 2009 classification, SD, DwoWS, DwWS and non-SD, because the timing of blood drawing was not known and there was an overlapping confidence interval among the clinical classification. Hence, these pooled blood parameter values could not be used to guide clinicians in management and did not correlate with severity as in previous scientific literatures and guidelines.