[Predictors of Utilization of Cardiovascular and Respiratory Emergency Department Visits - what Impact does the Environment have?] / Prädiktoren der Inanspruchnahme von kardiovaskulären und respiratorischen Notfallaufnahmen ­ welchen Einfluss hat die Umwelt?

AIM: There has been an increasing number of emergency department (ED) visits recently. It is unclear whether, in addition to a shift in services from the outpatient to the inpatient sector, other causes, (e. g. environmental factors), play a role. The aim was to investigate associations between the number of cardiovascular and respiratory ED visits and environmental variables. METHODS: Highly correlated environmental data were subjected to a principal component analysis. By using cross-correlation functions, environmental variables with time lags that showed the highest correlation with the number of ED visits were taken into consideration in the UNIANOVA analysis model, together with, among others, the day of the week and interaction terms. RESULTS: The final regression model explained 47% of the variation in respiratory ED visits demonstrating main effects for Mondays (B=10.69; p<0.001). Season showed significant effects with highest ED visits in autumn. No direct associations between environmental variables and number of respiratory ED visits were found. The results for the cardiovascular outcome were less expressive (R2=0.20). Again, the day of the week had the main effect on cardiovascular ED visits (p<0.001). CONCLUSIONS: The results suggest that weekdays had the main effect on ED visits. In future, we will collect and analyze environmental data at the micro level to achieve a higher model quality and better interpretability.

Temporal analysis of determinants for respiratory emergency department visits in a large German hospital.

INTRODUCTION: Associations between air pollutants, meteorological conditions and respiratory diseases have been extensively shown. The aim of this study was to investigate associations between daily meteorological data, data on air pollution and emergency department (ED) visits depending on the day of the week, season and year (study period from 2013 to 2015). METHODS: Highly correlated environmental data entered a categorical principal components analysis (CATPCA). We analysed cross-correlation functions between the time series of the respective daily environmental factors and daily ED visits. Time lags with peak correlations of environmental variables obtained by the CATPCA on ED visits together with day of the week, year, running day (linear, quadratic and cubic), season and interaction terms entered the univariate analysis of variance (UNIANOVA) model. RESULTS: The analyses demonstrated main effects on ED visits for the day of the week with highest admission rates on Mondays (B=10.69; ƞ2=0.333; p<0.001). A significant time trend could be observed showing increasing numbers of ED visits per each year (p<0.001). The variable 'running day' (linear, quadratic and cubic) indicated a significant non-linear effect over time. The variable season showed significant results with winter, spring and summer recording fewer ED visits compared with the reference season autumn. Environmental variables showed no direct associations with respiratory ED visits. DISCUSSION: ED visits were significantly associated with temporal variables. Our data did not show direct associations between environmental variables and ED visits.In times of rapid urbanisation, increases in respiratory diseases, temperature and air pollution, our analyses can help focus future studies and enhance strategies to reduce increasing numbers of respiratory diseases and ED visits. Because the potential costs of medical care in hospitals can be high compared with physicians, public health recommendations for reducing the increasing ED visits should be promoted and evaluated.

Evaluation of thermal indices for their applicability in obstacle-resolving meteorology models.

A thermally comfortable design of outdoor spaces favors social interaction and outdoor activities and thus contributes to the overall well-being of urban dwellers. To assess such a design, obstacle-resolving models (ORM) combined with thermal indices may be used. This paper reviews existing thermal indices to identify those suitable for thermal comfort assessment with ORMs. For the identification, 11 criteria and six index features are derived from literature analysis focusing on the characteristics of human environmental heat exchange, of outdoor urban environments, and of ORMs. An air temperature weighted world population distribution is calculated to derive the minimal air temperature range; a thermal index should cover to be applicable to 95% of the world population. The criteria are applied to 165 thermal indices by reviewing their original publications. Results show that only four thermal indices are suitable to be applied globally in their current form to various outdoor urban environments and also fulfill the requirements of ORMs. The evaluation of the index features shows that they differ with respect to the comprehensiveness of the thermophysiological model, the assessed human response, the treatment of clothing and activity, and the computational costs. Furthermore, they differ in their total application frequency in past ORM studies and in their application frequency for different climatic zones, as a systematic literature analysis of thermal comfort studies employing ORMs showed. By depicting the differences of the thermal indices, this paper provides guidance to select an appropriate thermal index for thermal comfort studies with ORMs.