title: Evaluation of a heat warning system in Adelaide, South Australia, using case-series analysis.
abstract: Heatwave warning systems aim to assist in reducing health effects during extreme heat. Evaluations of such systems have been limited. This study explored the effect of a heatwave warning programme on morbidity and mortality in Adelaide, South Australia, by comparing extreme events in 2009 and 2014, the latter with exposure to the preventive programme.
  
  
  
  The health outcomes during the two heatwaves were compared using the incidence rate ratios (IRRs) of daily ambulance call-outs, emergency presentations and mortality data during the heatwaves compared with non-heatwave periods during the warm seasons. Excess or reduced numbers of cases were calculated and the differences in cases between the two heatwaves were estimated.
  
  
  
  IRRs for total ambulance call-outs and emergency presentations were lower during the 2014 heatwaves compared with the 2009 event. The estimated differences in health-specific outcomes between 2009 and 2014 were statistically significant with 207 (59%) for cardiac-related call-outs, 134 (30%) for renal and 145 (56%) for heat-related emergency presentations. Mortality was not reduced in 2014. There were an estimated 34.5 excess deaths in 2009 and 38.2 in 2014.
  
  
  
  Morbidity outcomes were reduced significantly during the 2014 event. The fact that cardiac, renal and heat-related diagnoses were significantly reduced is likely to be associated with the intervention in 2014, which comprised a public warning through media and intense preventive measures directed to individual populations at risk. Further analysis of risk factors of mortality during heatwaves should be explored.
authors.affiliation: Public Health Services, Department for Health and Ageing, Adelaide, South Australia, Australia School of Public Health, University of Adelaide, Adelaide, South Australia, Australia.
authors.forename: Monika
authors.initials: M
authors.lastname: Nitschke
authors.affiliation: Epidemiology, Department for Health and Ageing, Adelaide, South Australia, Australia School of Medicine, University of Adelaide, Adelaide, South Australia, Australia.
authors.forename: Graeme
authors.initials: G
authors.lastname: Tucker
authors.affiliation: School of Public Health, University of Adelaide, Adelaide, South Australia, Australia.
authors.forename: Alana
authors.initials: A
authors.lastname: Hansen
authors.affiliation: School of Public Health, University of Adelaide, Adelaide, South Australia, Australia.
authors.forename: Susan
authors.initials: S
authors.lastname: Williams
authors.affiliation: International Public Health, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Public Health, University of Adelaide, Adelaide, South Australia, Australia.
authors.forename: Peng
authors.initials: P
authors.lastname: Bi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000552:Ambulances; D002648:Child; D002675:Child, Preschool; D003142:Communication; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D055874:Extreme Heat; D005260:Female; D006331:Heart Diseases / Q000209:etiology / Q000401:mortality / Q000517:prevention & control*; D018882:Heat Stress Disorders / Q000209:etiology / Q000401:mortality / Q000517:prevention & control*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007674:Kidney Diseases / Q000209:etiology / Q000401:mortality / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D009017:Morbidity; D015980:Public Health Practice; D012307:Risk Factors; D012621:Seasons; D013021:South Australia / Q000453:epidemiology; D055815:Young Adult
keywords: heatwave; intervention; prevention; warning system