Time-trend analysis between extremely cold temperatures and daily mortality from circulatory and respiratory causes in Castilla-La Mancha, Spain
As a result of Climate Change it is expected that health effects due to cold waves increases in the next future. Particularly, mortality from circulatory and respiratory causes. People older 65 years are the target population for the effects on health of extremes temperatures. Objective:To analyze the temporal evolution of the relationship between extremely cold temperatures and daily mortality for circulatory and respiratory causes in Castile-La Mancha (CLM), area located in the center of Spain, in the period 1975-2008.
METHODS:
Series of daily mortality data for circulatory (ICD-10: I00-I99) and respiratory causes (ICD-10: J00-J99) in CLM between January 1, 1975 and December 31, 2008 were used. Data were provided by the National Statistics Institute. The daily minimum temperatures data correspond to Toledo observatory and was provided by AEMET. Three stages were differentiated 1975-1985, 1986-1996 and 1997-2008. Box-Jenkins models were performed to quantify the percentage increase (PI) in mortality for each degree in which the daily minimum temperature is below -2ºC.
RESULTS:
For circulatory causes, there was a decreasing trend in PI in mortality with statistically significant association. In the 1975-1985 period the PI was 15.1% (±1.1); in the 1986-1996 period was 7.8% (±0.1) and 2.0% (±1.0) in the 1997-2008 period. However, for respiratory mortality there was a homogenous trend with statistically significant association with cold temperatures in PI in the first period 20.9%(±2.0) and in the second period 17.4%(±0.2). In the last period, the PI decreased to 2.8%(±0.5).
CONCLUSIONS:
There is a decreasing PI in cardiovascular mortality with statistically significant associations with the minimum temperature in the period 1975-2008 in CLM. For respiratory mortality there is a homogenous PI in the first and second period and a decreasing PI in the last period in CLM. Socio-economic and demographic variables and improvements in the treatments of cardiovascular diseases might be involved in these results.