Epidemiology of hypothermia: fatalities and hospitalisations in New Zealand.
BACKGROUND
Hypothermia occurs within domestic and non-residential settings. Most epidemiological data originate from the northern hemisphere, with little data being generally available concerning cases from New Zealand and Australia.


OBJECTIVE
The National Health Statistics Centre (New Zealand) records hospital discharges and deaths. This study isolated hypothermia cases, to quantify its incidence and identify risk groups.


METHODS
The morbidity and mortality files for the years 1979-86 (cases = 3,808,717) and 1977-86 (cases = 259,325; respectively) were searched by three investigators.


RESULTS
Hypothermia hospitalisations were identified (6.9 per 100,000 per year). There were 176 deaths from hypothermia, representing 0.07% of the 259,325 deaths from all causes for the same period (0.537 per 100,000 people per year); of these fatalities, 72.2% were classified as domestic, and 27.8% as non-residential; of the domestic fatalities, 86.6% were 65 + years and 35.5% of these were male. Within the non-residential category, 75.5% were aged 13-65, of which 94.6% were male. The hospitalisation incidence was 12.7 times the fatality incidence, with the majority of hospitalisations being of domestic origin (88.4% of total), and occurring mostly within the lower and upper age extremes. Neonatal domestic hypothermia accounted for 72.6% of all domestic hospitalisations, and the elderly constituted 72.0% of the remaining cases. The proportion of New Zealand fatalities caused by hypothermia was 0.067%; lower than reported in the United Kingdom.


CONCLUSIONS
The two main non-neonatal groups contributing to cases of hypothermia were males aged 13-65 years, and the elderly. In the aged, the proportion of hypothermia-related deaths was no different from that associated with other disorders, however, the case-fatality ratio was three times greater, highlighting the need for improving prevention and management strategies.
Taylor
N A
NA
Division of Science, University of Otago, Dunedin, New Zealand.
Griffiths
R F
RF
Cotter
J D
JD
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007035:Hypothermia / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D009520:New Zealand / Q000453:epidemiology; D012307:Risk Factors