Effects of Temperature and Air Pollution on Urgent Hospital Admissions in the Czech Republic

Previous studies have shown associations between extreme temperatures and the risk of urgent hospital admissions. However, less is known about the role that air pollutants play in this association in Central and Eastern Europe. This study aimed to distinguish the independent effects of temperature and air pollutants on urgent hospital admissions in the general population of the Czech Republic. 

We use data on daily urgent hospital admissions (all-cause, cardiovascular, and respiratory), mean ambient temperature, and air pollutants (PM10, NO2, SO2, O3) from 1998 to 2018. Using a multi-exposure and two-step approach, we applied distributed lagged non-linear models (DLNM) to understand the non-linear and 21-day lagged effects of temperature, as well as the linear effects of air pollutants, on hospitalizations in the 14 Czech regions. Later, we estimated the pooled effects using meta-regression techniques. Additionally, we did a separate analysis by age and sex categories.  

Meta-regression pooled estimates showed that for the Czech Republic, the 1st percentile of temperature was associated with increased risk ratio (RR) of respiratory admissions (RR=1.20, CI:1.16-1.25). In contrast, the 99th percentile of temperature was associated with increased risk of all-cause admissions (RR=1.05, CI:1.03-1.07). A 10 µg/m3 increase in NO2 was associated with increased risk of all-cause (RR=1.013, CI:1.010-1.015) and cardiovascular (RR=1.015, CI:1.011-1.019) admissions. Associations were stronger for the age group 5 to 19 years (all-cause RR=1.030, CI:1.025-1.034; cardiovascular RR=1.042, CI:1.012-1.074), including respiratory admissions (RR=1.020, CI:1.009-1.032). Other pollutants did not show statistically significant associations.  

Extreme temperatures and rising NO2 concentrations are likely to increase the risk of urgent hospital admissions in the Czech Republic. Children and adolescents seem to be the most vulnerable group to these environmental exposures. Therefore, public health measures must address environmental necessities, while pediatric units prepare for the potential increased hospitalization demand. Exposures measured at the individual level are essential to confirm these findings.