A Case-Crossover Analysis of Out-of-Hospital Coronary Deaths and Air Pollution in Rome, Italy

Abstract

Air pollutants originating from combustion processes, including ultrafine particles, are related to fatal, nonhospitalized coronary events. The effect is stronger among people over 65 years of age, but is not limited to a group with a specific comorbidity.

Daily mortality and particulate matter in different size classes in Erfurt, Germany

“…Medication use in asthmatics also increased in association with the cumulative exposure to UFP over 5 or even 14 days (von Klot et al, 2002). Ru¨ckerl et al (2006) observe the highest increases in some blood markers in patients with coronary heart disease at a lag of 48 to 71 h. However, other studies observed immediate associations of UFP on mortality or morbidity, respectively (Forastiere et al, 2005;von Klot et al, 2005).…”

“…Evidence suggests that increased PM concentrations mainly affect the cardiovascular and respiratory systems (Peters et al, 1997a(Peters et al, , 1999Gold et al, 2000;Ibald-Mulli et al, 2001;Brook et al, 2002;Devlin et al, 2003;Schulz et al, 2005) and are especially associated with increased cardiovascular hospital admissions (Schwartz, 1999;Zanobetti et al, 2000;Le Tertre et al, 2002;D'Ippoliti et al, 2003;von Klot et al, 2005;Dominici et al, 2006) or increased cardiovascular mortality (Clancy et al, 2002;Forastiere et al, 2005;Zeka et al, 2005;Ostro et al, 2006). The physical or chemical particle properties (e.g.…”

“…Recently, adverse health effects were reported for elevated particle number concentrations (NC) in the ultrafine range Ibald-Mulli et al, 2002) including a decrease in peak expiratory flow (PEF) (Pekkanen et al, 1997;Peters et al, 1997b;Penttinen et al, 2001), increases in medication use of asthmatics (von Klot et al, 2002), increases in blood markers (Ru¨ckerl et al, 2006), repolarization changes in ischemic heart disease patients (Henneberger et al, 2005), increased hospital cardiac readmissions in myocardial infarction survivors (von Klot et al, 2005) and an increase in out-of-hospital coronary deaths (Forastiere et al, 2005). Associations of mortality with UFPs have been reported to be of approximately the same magnitude per interquartile range as with PM 2.5 but independent of the PM 2.5 associations in a 3-year study , reanalyzed by Sto¨lzel et al, 2003.…”

Effect of air pollution on onset of acute coronary syndrome in susceptible subgroups

“…There are some limitations to our study, however, that may originate from unidirectional case-crossover studies. Such designs might be sensitive to trends in the exposure and the outcome [27,28]. There is the possibility of downward bias in this study due to the relatively short interval (1 week) between the hazard and control periods that may lead to low variability of exposure.…”

“…Confounding may occur because of time-varying risk factors [27,28], such as time of day or weather conditions, which were considered in the multivariate analysis. As individuals comprise study units in this type of study, this approach can assess effect modification by within-person factors; however, the statistical power of the method is lower than in time-series analysis [29,30].…”