Sambanden mellan inandningsbara, grova och fina partiklar i luften och strokeanfall i Malmö
TransferfunktionsmodellTidsserieanalysStrokePartiklarStatisticsOperations researchProgrammingActuarial mathematicsStatistikOperationsanalysProgrammeringAktuariematematikMathematics and Statistics
In the western world, strokes are the third most common cause of death, hitting mainly the elderly population. Smoking, high blood pressure, diabetes and overweight are known risk factors for causing strokes. Previous studies show that an increased level of particulate matter, PM, is also related to an increased number of strokes. The population in this study consists of patients over 65 years old who live in Malmö. Levels of particulate matter were measured from October 2004 to April 2005 at a central outdoor monitoring site in Malmö. The data is divided according to the cold and to the warm season. The cold season ranges from October to April and the warm season from May to September. The purpose of this study is to build models which describe the short-term association between the number of strokes recorded and PM10, PM2.5 and PM10-PM2.5 respectively. A short-term association means that the incidence of strokes is related to the content of PM in the air that was present up to seven days prior to the stroke. Some meteorological variables may affect the level of PM in the air; therefore, it is possible that these variables might have an indirect association with having a stroke. Taking that into consideration, we have also analysed the association between meteorological variables and the occurrence of strokes in this study. Univariate ARIMA-models and transfer function models are used to find these associations. The results from the analysis show that there is a positive association between PM10, PM2.5 and PM10-PM2.5 and having a stroke, but only during the cold season. There is no evidence of any connection between meteorological variables and the occurrence of strokes.