title: Factors influencing performance of internet-based biosurveillance systems used in epidemic intelligence for early detection of infectious diseases outbreaks.
abstract: BACKGROUND
  Internet-based biosurveillance systems have been developed to detect health threats using information available on the Internet, but system performance has not been assessed relative to end-user needs and perspectives.
  
  
  RESULTS
  Infectious disease events from the French Institute for Public Health Surveillance (InVS) weekly international epidemiological bulletin published in 2010 were used to construct the gold-standard official dataset. Data from six biosurveillance systems were used to detect raw signals (infectious disease events from informal Internet sources): Argus, BioCaster, GPHIN, HealthMap, MedISys and ProMED-mail. Crude detection rates (C-DR), crude sensitivity rates (C-Se) and intrinsic sensitivity rates (I-Se) were calculated from multivariable regressions to evaluate the systems' performance (events detected compared to the gold-standard) 472 raw signals (Internet disease reports) related to the 86 events included in the gold-standard data set were retrieved from the six systems. 84 events were detected before their publication in the gold-standard. The type of sources utilised by the systems varied significantly (p<0001). I-Se varied significantly from 43% to 71% (p=0001) whereas other indicators were similar (C-DR: p=020; C-Se, p=013). I-Se was significantly associated with individual systems, types of system, languages, regions of occurrence, and types of infectious disease. Conversely, no statistical difference of C-DR was observed after adjustment for other variables.
  
  
  CONCLUSIONS
  Although differences could result from a biosurveillance system's conceptual design, findings suggest that the combined expertise amongst systems enhances early detection performance for detection of infectious diseases. While all systems showed similar early detection performance, systems including human moderation were found to have a 53% higher I-Se (p=00001) after adjustment for other variables. Overall, the use of moderation, sources, languages, regions of occurrence, and types of cases were found to influence system performance.
authors.affiliation: International Department, French Institute for Public Health Surveillance (Institut de Veille Sanitaire), Saint Maurice, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Barboza
authors.affiliation: International Department, French Institute for Public Health Surveillance (Institut de Veille Sanitaire), Saint Maurice, France.
authors.forename: Laetitia
authors.initials: L
authors.lastname: Vaillant
authors.affiliation: Infectious Department, French Institute for Public Health Surveillance (Institut de Veille Sanitaire), Saint Maurice, France.
authors.forename: Yann
authors.initials: Y
authors.lastname: Le Strat
authors.affiliation: Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, D.C, United States of America; Imaging Science and Information Systems Center, Georgetown University School of Medicine, Washington, D.C, United States of America.
authors.forename: David M
authors.initials: DM
authors.lastname: Hartley
authors.affiliation: Department of Pediatrics, Georgetown University Medical Center, Washington, D.C, United States of America.
authors.forename: Noele P
authors.initials: NP
authors.lastname: Nelson
authors.affiliation: Centre for Emergency Preparedness and Response, Public Health Agency of Canada, Ottawa, Canada.
authors.forename: Abla
authors.initials: A
authors.lastname: Mawudeku
authors.affiliation: ProMED-mail, International Society for Infectious Diseases, Boston, Massachusetts, United States of America.
authors.forename: Lawrence C
authors.initials: LC
authors.lastname: Madoff
authors.affiliation: Joint Research Centre of the European Commission, Ispra, Italy.
authors.forename: Jens P
authors.initials: JP
authors.lastname: Linge
authors.affiliation: National Institute of Informatics, Tokyo, Japan; The European Bioinformatics Institute, Cambridge, United Kingdom.
authors.forename: Nigel
authors.initials: N
authors.lastname: Collier
authors.affiliation: Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: John S
authors.initials: JS
authors.lastname: Brownstein
authors.affiliation: École des Hautes Études en Santé Publique (EHESP), University school of public Health, PRES Sorbonne Cité, Paris, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Astagneau
mesh_terms: D055877:Biosurveillance / Q000379:methods*; D003140:Communicable Disease Control / Q000379:methods; D003141:Communicable Diseases / Q000453:epidemiology*; D003627:Data Interpretation, Statistical; D004196:Disease Outbreaks; D005602:France; D006801:Humans; D016012:Poisson Distribution; D012680:Sensitivity and Specificity