Variables considered for the statistical analyses
| Name of the variable | Unit | Minimum | Median | Maximum |
| Indication | ||||
| COPD (ICD-10 J44) | Cases per day* | 0 | 7 | 20 |
| Asthma bronchiale (ICD-10 J45) | Cases per day* | 0 | 4 | 13 |
| Determinants | ||||
| Day of the week | Monday to Sunday | – | – | – |
| Season | Winter, spring, summer, autumn† | – | – | – |
| Year | 2013, 2014, 2015 | – | – | – |
| Running day | Day | – | – | – |
| Running day² | Day | – | – | – |
| Running day³ | Day | – | – | – |
| Tmean | (°C‡) | −10.3 | 9.9 | 27.2 |
| Tmax | (°C)‡ | −8.7 | 13.9 | 36.4 |
| Tmin | (°C)‡ | −12.5 | 5.8 | 19.2 |
| Daily mean relative humidity§ | (%)‡ | 42.5 | 82.0 | 100.0 |
| Daily mean vapour pressure§ | (hPa)‡ | 2.2 | 9.7 | 23.1 |
| PETmean§ | (°C)‡ | −18.0 | 5.6 | 29.1 |
| PETmax§ | (°C)‡ | −15.1 | 12.5 | 44.0 |
| PETmin§ | (°C)‡ | −20.5 | 0.0 | 15.1 |
| Daily mean wind speed§ | (m/s)‡ | 0.6 | 3.9 | 10.3 |
| NO concentrations§ | (µg/m3)‡ | 2.0 | 4.3 | 110.6 |
| PM10 concentrations§ | (µg/m3)‡ | 4.5 | 17.8 | 84.6 |
| O3 concentrations§ | (µg/m3)‡ | 1.4 | 46.6 | 132.2 |
Environmental data were retrieved for the airport station Hamburg-Fuhlsbüttel. Minimum, maximum and median values are shown for the analysis period (2013–2015).
*Time interval from 1 January 2013 to 31 December 2015.
†Winter: December, January, February; spring: March, April, May; summer: June, July, August; autumn: September, October, November.
‡Time interval from 1 December 2012 to 31 December 2015.
§Variables selected for the final categorical principal component analysis.
COPD, Chronical Obstructive Pulmonary Syndrome; NO, nitric oxide; O3, ozone; PET, physiological equivalent temperature; PM10, particulate matter with an aerodynamic diameter of ≤10 µm; T, daily temperature.