Seasonal mortality variations of cardiovascular, respiratory and malignant diseases in the City of Belgrade
Authors: Stanisic-Stojic Svetlana , Stanisic Nemanja , Stojic Andreja , Dzamic Vladimir 
Published: October 2016

The main purpose of this paper is to examine seasonal variations in mortality
resulting from cardiovascular diseases, respiratory diseases and cancer, as
well as to provide a review of environmental factors underlying such
phenomenon. The herein presented study was conducted on the territory of
Belgrade based on the data on daily mortality rates obtained from the
Institute of Public Health in Belgrade for the period 2009-2014, as well as
the data on annual mortality rates provided by the Statistical Office of the
Republic of Serbia for the period 2000-2014. The analysis of mortality
variations was performed by the use of Theil-Sen method, smooth trend method
and cubic spline interpolation, whereas desriptive tools, such as
winter/summer ratio and dissimilarity index, were used to examine the
seasonal pattern. According to the Institute of Public Health, over 113430
deaths were registered in Belgrade area for the period 2009-2014, out of
which 53.25% is attributed to cardiovascular diseases, 4.01% to respiratory
diseases and 27.50% to cancer. The annual mortality rates caused by
cardiovascular diseases and cancer on the territory of Belgrade are among the
highest ranking in Europe. The leading causes of death in the observed period
included: cardiomyopathy, heart attack and stroke with accompanying
complications, breast cancer in women, prostate and colorectal cancer in men,
lung and bronchus cancer for both genders, and chronic obstructive pulmonary
disease. Cardiovascular and respiratory mortality rates are significantly
higher among people aged 65 and over, whereas more than one third of deaths
caused by cancer is observed among younger people aged between 45 and 64
years. Research results show that seasonal variations were most pronounced in
mortality resulting from cardiovascular and respiratory diseases, with
highest mortality rates recorded in February and March and lowest during the
summer season. Also, the number of deaths due to cardiovascular diseases
increased twice, namely at the end of June and October, which is assumed to
be the result of sudden temperature changes. Nonetheless, no such seasonal
variations were observed in mortality caused by cancer. Seasonal variations
in mortality resulting from cardiovascular diseases also indicate gender
differences, which is why sudden temperature changes in interim periods
affect more women than men. As regards deseasonalized trend, mortality caused
by cardiovascular diseases stagnates, while mortality caused by cancer and
mortality caused by respiratory diseases records moderate to severe increase.
This is a uniform trend in almost all municipalities in Belgrade, with
average mortality rates being higher in central zones than in suburbs over
the last 15 years, particularly mortality caused by cancer. A slight increase
in the overall mortality can also be attributed to aging of the population,
which cannot be verified due to lack of available accurate data on the
average age structure of Belgrade population for the observed period. A
better understanding of seasonal variations in mortality caused by chronic
non-communicable diseases can contribute to improving the population health
care and rising awareness of the population concerning greater health care in
changeable weather conditions due to global warming and climate change. These
findings can also enhance preventive action on environmental risk factors
that are not limited exclusively to weather conditions, such as air
pollution.