title: Early warning and NHS Direct: a role in community surveillance?
abstract: BACKGROUND
  NHS Direct is a nurse-led telephone help line that covers the whole of England and Wales. NHS Direct derived data are being used for community surveillance, the purpose of which is to detect a local or national increase in symptoms reported by callers. The system has the potential to identify an increase in symptoms reported by callers about people in the prodromal stages of illness caused by the deliberate release of a biological or chemical agent. There are no other community surveillance projects existing on a national scale that utilize electronic daily data.
  
  
  METHODS
  We describe the surveillance system and calls to NHS Direct between December 2001 and July 2002. Confidence limits have been constructed for 10 key algorithms at each site and control charts devised for five of these algorithms at sites covering the key urban areas.
  
  
  RESULTS
  Daily reporting has been achieved from NHS Direct sites in England and Wales. High levels of activity in specific algorithms at both national and regional levels have been detected. A sustained national increase in calls about fever occurred in January 2002.
  
  
  CONCLUSIONS
  Although the project is still at an early stage, daily analysis of NHS Direct data has the potential to detect symptoms in the community that could be related to deliberate releases of chemical or biological agents or to outbreaks of disease. For this surveillance to act as an 'early warning' of illness resulting from a microbiological or chemical cause, the NHS Direct surveillance needs to be fully integrated into an appropriate public health response (which may require diagnostic samples to be taken from callers).
authors.affiliation: Royal College of General Practitioners, 14 Princes Gate, Hyde Park, London SW7 1PU, UK.
authors.forename: Maureen
authors.initials: M
authors.lastname: Baker
authors.forename: Gillian E
authors.initials: GE
authors.lastname: Smith
authors.forename: Duncan
authors.initials: D
authors.lastname: Cooper
authors.forename: Neville Q
authors.initials: NQ
authors.lastname: Verlander
authors.forename: Frances
authors.initials: F
authors.lastname: Chinemana
authors.forename: Sarafina
authors.initials: S
authors.lastname: Cotterill
authors.forename: Vivien
authors.initials: V
authors.lastname: Hollyoak
authors.forename: Rod
authors.initials: R
authors.lastname: Griffiths
mesh_terms: D000293:Adolescent; D023482:Bioterrorism; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D006296:Health Services; D015277:Hotlines / Q000706:statistics & numerical data*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D009313:National Health Programs / Q000458:organization & administration*; D011159:Population Surveillance / Q000379:methods*; D006113:United Kingdom / Q000453:epidemiology