title: Validation of dengue infection severity score.
abstract: OBJECTIVE
  To validate a simple scoring system to classify dengue viral infection severity to patients in different settings.
  
  
  METHODS
  The developed scoring system derived from 777 patients from three tertiary-care hospitals was applied to 400 patients in the validation data obtained from another three tertiary-care hospitals. Percentage of correct classification, underestimation, and overestimation was compared. The score discriminative performance in the two datasets was compared by analysis of areas under the receiver operating characteristic curves.
  
  
  RESULTS
  Patients in the validation data were different from those in the development data in some aspects. In the validation data, classifying patients into three severity levels (dengue fever, dengue hemorrhagic fever, and dengue shock syndrome) yielded 50.8% correct prediction (versus 60.7% in the development data), with clinically acceptable underestimation (18.6% versus 25.7%) and overestimation (30.8% versus 13.5%). Despite the difference in predictive performances between the validation and the development data, the overall prediction of the scoring system is considered high.
  
  
  CONCLUSIONS
  The developed severity score may be applied to classify patients with dengue viral infection into three severity levels with clinically acceptable under- or overestimation. Its impact when used in routine clinical practice should be a topic for further study.
authors.affiliation: Clinical Epidemiology Program, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand ; Department of Occupational Medicine, Phrae Hospital, Phrae, Thailand.
authors.forename: Surangrat
authors.initials: S
authors.lastname: Pongpan
authors.affiliation: Clinical Epidemiology Program, Faculty of Medicine, Thammasat University, Bangkok, Thailand.
authors.forename: Jayanton
authors.initials: J
authors.lastname: Patumanond
authors.affiliation: Department of Social Medicine, Sawanpracharak Hospital, Nakorn Sawan, Thailand.
authors.forename: Apichart
authors.initials: A
authors.lastname: Wisitwong
authors.affiliation: Clinical Epidemiology Society at Chiang Mai, Chiang Mai, Thailand.
authors.forename: Chamaiporn
authors.initials: C
authors.lastname: Tawichasri
authors.affiliation: Clinical Epidemiology Program, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand ; Department of Radiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
authors.forename: Sirianong
authors.initials: S
authors.lastname: Namwongprom
keywords: clinical prediction rule; dengue hemorrhagic fever; dengue shock syndrome; validation