The European Journal of Public Health Advance Access originally published online on November 28, 2007
The European Journal of Public Health 2008 18(3):317-322; doi:10.1093/eurpub/ckm108
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Health Services Research |
Impact of high temperatures on hospital admissions: comparative analysis with previous studies about mortality (Madrid)
C. Linares1 and J. Díaz2
Department of Education for Sustainable Development of the Madrid City Council, Autónoma University General Foundation of Madrid, Madrid, Spain
1 PEAC. Centro Nacional de Epidemiología. Instituto de Salud Carlos III. Madrid
2 Escuela Nacional de Sanidad. Instituto de Salud Carlos III. Madrid
Correspondence: Dr Julio Díaz Jiménez. Escuela Nacional de Sanidad. Instituto de Salud Carlos III. C/ Sinesio Delgado 6. 28029 Madrid. Tel: +34 918222280, Fax: +34 913877809, e-mail: julio.diaz{at}uam.es
Received November 30, 2006 , accepted October 1, 2007
Background: Heat wave prevention plans are traditionally implemented according to a temperature limit above which mortality begins to rise. Although these prevention plans are obviously designed to avoid deaths, it is also necessary to establish the impact of extreme temperatures on hospital admissions in order to put hospital alert plans into action for dealing with people affected by heat wave victims.
Methods: We used data on daily emergency admissions between May and September, from 1995 to 2000, in the Hospital General Universitario Gregorio Marañón in Madrid. The causes for admission were considered as ‘organic’ (International Classification of Diseases, ICD-9: 1–799), circulatory (ICD-9: 390–459) and respiratory (ICD-9: 460–519). We stratified them according to the following age groups: all ages, from 0 to 10, 18 to 44, 45 to 64, 65 to 74 and above 75 years. The methodology used was Autorregresive Integrated Moving Average (ARIMA) modelling, including variables related to atmospheric pollution, seasonality and trends.
Results: The results show that the temperature above which hospital admissions soar coincides with the temperature limit above which mortality sharply rises, which, in turn, coincides with percentile 95 of the maximum daily temperature series for summer months. The pattern of hospital admissions is completely different from that of mortality. The rise in hospital admissions due to all causes and age groups is clearly smaller than that detected for mortality.
Discussion: These results suggest that people die rapidly from circulatory diseases before they can be admitted to hospital. This datum is vital with regard to implementing prevention plans prior to the arrival of the heat wave, if they are to effectively reduce mortality.
Keywords: heat wave, hospital admissions, mortality, prevention plans, temperature