title: [An experimental study for syndromic surveillance using OTC sales].
abstract: OBJECTIVE
  We analyzed the possibility of using sales data on over-the-counter (OTC) medicine in syndromic surveillance for early detection and/or prediction of influenza pandemics.
  
  
  METHODS
  Data who collected on daily November 2003-April 2004 sales of common cold medication commercially obtained from 600 pharmacies in Japan enrolled in reporting throughout the 2003/04 influenza season. OTC sales data were compared to daily influenza incidence data to determine correlations and predictability. Data included Sentinel Surveillance of influenza, National Surveillance of Dally Influenza Outpatients (Daily Case Reporting: DCR), and Mailing-List-Based Influenza Epidemic Database (MLflu).
  
  
  RESULTS
  The seasonal influenza epidemic peak for 2003-2004 was observed on January 30, February 1, and February 2 for sentinel surveillance, DCR, and MLflu. Sales peaks of OTC medicines occured twice in 2003-2004 season, once at the end of the year and once on January 27. Peak OTC sales for common cold medication per pharmacy were preceded by 18, 21, and 13 days for sentinel surveillance, DCR, and MLflu. OTC sales successfully explained 74-85% in the variation of influenza incidence which is interpretable as sufficient power of explanation.
  
  
  CONCLUSIONS
  OTC sales proved to be a good indicator of real-time surveillance for influenza epidemics. Further analysis on multiyear data is needed to demonstrate the robustness of results. To confirm the advantage in the system of real-time syndromic surveillance, it is also necessary to check explanatory power of OTC sales on the variation of influenza incidence with prospective datasets.
authors.forename: Tamie
authors.initials: T
authors.lastname: Sugawara
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ohkusa
authors.forename: Mika
authors.initials: M
authors.lastname: Shigematsu
authors.forename: Kiyosu
authors.initials: K
authors.lastname: Taniguchi
authors.forename: Atsuo
authors.initials: A
authors.lastname: Murata
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Okabe
mesh_terms: D003139:Common Cold / Q000188:drug therapy; D017723:Drug Utilization Review; D006801:Humans; D007251:Influenza, Human / Q000453:epidemiology*; D007564:Japan; D004366:Nonprescription Drugs; D015995:Prevalence
chemical_list: D004366:Nonprescription Drugs