Effect of weather temperature on hospital emergencies in the region of Murcia, Spain, throughout the 2000-2005 and its use in epidemiological surveillance

Background: The effect of the weather temperature on mortality has been studied more in depth than its effect on morbidity. In Murcia, the number of daily emergencies and the cases of heat stroke for which care is provided at the hospitals in this Region have been studied. Objective: to evaluate the effect that the weather temperature has on the number of hospital emergencies and the use of these indicators for the surveillance of hot weather-related morbidity. Methods: The effect of the weather temperature on the number of summertime emergencies (2000-2005) has been studied by estimating the percentage increase in emergencies when the weather temperature thresholds established by the Ministry of Health and Consumer Affairs (Max. 38 degrees C and Min. 22.4 degrees C) are exceeded, and by each degree of temperature rise. Results have been stated as Relative Risk (RR) with a 95% Cl. A comparison has been drawn between the heat strokes notified and the hospital admissions recorded in the Minimum Basic Data Set at Hospital Discharge (MBDS). Results: Within the 2000-2005 period, the number of emergencies rose by 1.6% on those days when the minimum temperature for the day was above 22.4 degrees C (RR: 1.016; 95%CI 1.0076 - 1.0244) and by 0.21% for each degree of rise in the minimum temperature for the day (RR: 1.0021, 95% CI 1.0000-1.0044). A total of 38% of the heat strokes admitted to hospital were not reported, of which 40% had occupational exposure. Conclusions: The minimum temperature for the day could have a greater effect in Murcia than the maximum for the day. Based on the current thresholds, the number of emergencies/day does not seem to be a suitable indicator for monitoring the effect of the weather temperatures information on the diagnosis and the age being needed. Heat strokes provide partial information on the impact, but highlight less-considered population groups at risk.