title: The health impacts of heat waves in five regions of New South Wales, Australia: a case-only analysis.
abstract: OBJECTIVE
  To determine and characterise the health impacts of extreme heat events on the population in five regions of New South Wales (NSW). Such data provide evidence necessary for the development of policy and programme initiatives designed to reduce the burden of disease due to the impact of climate change.
  
  
  METHODS
  A case-only approach was used to analyse 1,497,655 emergency hospital admissions in Sydney East and West, Illawarra, Gosford-Wyong and Newcastle. The distribution of daily minimum and maximum temperatures in each region was used to define extreme heat (≥99th percentile). We investigated the susceptibility of the main causes of emergency hospital admission to extreme heat. We also examined the presence of underlying conditions as a risk modifier of emergency hospital admission on extreme heat. Logistic regression model was used to estimate the effect modifications.
  
  
  RESULTS
  Main causes: On days of extreme heat, the risk of emergency hospital admission due to heat-related injuries, dehydration and other disorders of fluid, electrolyte and acid-base balance increased more than the risk of admission from other causes. Underlying conditions: Those with underlying mental and behavioural disorders, diseases of nervous and circulatory system, especially cardiac, diseases of respiratory system, especially asthma and chronic obstructive pulmonary disease, neoplasms and renal disease, especially renal failure, were more susceptible to an extreme heat event.
  
  
  CONCLUSIONS
  In this study, we identified several main diagnoses and underlying conditions for emergency hospital admission that are particularly susceptible to extreme heat events. This knowledge can contribute directly to establishing health programmes that would effectively target those with higher relative risk of emergency hospital admission due to extreme heat.
authors.affiliation: Bureau of Health Information, Sydney, NSW, Australia. behnoosh.khalaj@bhi.nsw.gov.au
authors.forename: Behnoosh
authors.initials: B
authors.lastname: Khalaj
authors.forename: Glenis
authors.initials: G
authors.lastname: Lloyd
authors.forename: Vicky
authors.initials: V
authors.lastname: Sheppeard
authors.forename: Keith
authors.initials: K
authors.lastname: Dear
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002318:Cardiovascular Diseases / Q000150:complications; D002648:Child; D002675:Child, Preschool; D003681:Dehydration; D048909:Diabetes Complications; D004632:Emergency Medical Services / Q000706:statistics & numerical data*; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006358:Hot Temperature / Q000009:adverse effects*; D006801:Humans; D007674:Kidney Diseases / Q000150:complications; D016015:Logistic Models; D008297:Male; D001523:Mental Disorders / Q000150:complications; D008875:Middle Aged; D009422:Nervous System Diseases / Q000150:complications; D009517:New South Wales; D012140:Respiratory Tract Diseases / Q000150:complications; D012307:Risk Factors; D014882:Water-Electrolyte Balance; D014947:Wounds and Injuries; D055815:Young Adult
references.citation: Int J Biometeorol. 2005 Nov;50(2):121-9
references.pmid: 15912362
references.citation: Environ Health Perspect. 2008 Oct;116(10):1369-75
references.pmid: 18941580
references.citation: Lancet. 1997 May 10;349(9062):1341-6
references.pmid: 9149695
references.citation: Med J Aust. 2007 Dec 3-17;187(11-12):662-5
references.pmid: 18072911
references.citation: Am J Epidemiol. 2003 Jun 15;157(12):1074-82
references.pmid: 12796043
references.citation: Eur J Public Health. 2006 Dec;16(6):592-9
references.pmid: 16644927
references.citation: Med Hypotheses. 2006;66(5):1025-8
references.pmid: 16413137
references.citation: Epidemiology. 2006 May;17(3):315-23
references.pmid: 16570026
references.citation: Am J Public Health. 2007 Apr;97 Suppl 1:S158-62
references.pmid: 17413056
references.citation: Epidemiology. 2005 Jan;16(1):67-72
references.pmid: 15613947
references.citation: Environ Health Perspect. 2006 Sep;114(9):1331-6
references.pmid: 16966084
references.citation: Aust N Z J Public Health. 2000 Feb;24(1):89-91
references.pmid: 10777987
references.citation: Am J Respir Crit Care Med. 2009 Mar 1;179(5):383-9
references.pmid: 19060232
references.citation: Environ Health Perspect. 2006 Sep;114(9):1344-7
references.pmid: 16966086
references.citation: Rev Esp Salud Publica. 2008 Mar-Apr;82(2):153-66
references.pmid: 18496620
references.citation: BMC Public Health. 2007 Aug 09;7:200
references.pmid: 17688689
references.citation: Environ Health Perspect. 2001 Dec;109(12):1241-8
references.pmid: 11748031
references.citation: Eur Psychiatry. 2007 Sep;22(6):335-8
references.pmid: 17513091
references.citation: Eur Psychiatry. 2005 Jan;20(1):61-4
references.pmid: 15642446
references.citation: Occup Environ Med. 2004 Nov;61(11):893-8
references.pmid: 15477282
references.citation: Am J Public Health. 2004 Sep;94(9):1520-2
references.pmid: 15333307
references.citation: Int J Epidemiol. 1995 Jun;24(3):576-82
references.pmid: 7672899
references.citation: Epidemiology. 2006 Jan;17(1):75-9
references.pmid: 16357598
references.citation: Am J Prev Med. 1999 May;16(4):269-77
references.pmid: 10493281
references.citation: Eur J Public Health. 2008 Jun;18(3):317-22
references.pmid: 18045814
references.citation: BMC Med Inform Decis Mak. 2009 Feb 20;9:14
references.pmid: 19232122
references.citation: Euro Surveill. 2005 Jul;10(7):168-71
references.pmid: 16088043
references.citation: Epidemiology. 2003 Jul;14(4):467-72
references.pmid: 12843773
references.citation: Epidemiology. 2006 Nov;17(6):632-8
references.pmid: 17003686
references.citation: Am J Prev Med. 2002 May;22(4):328-9
references.pmid: 11988389
references.citation: Int Arch Occup Environ Health. 2002 Mar;75(3):163-70
references.pmid: 11954983