Austria is on target to be first European country to ease restrictions…statistical control charts can explain why…
Austria is planning to ease lockdown restrictions after Easter. Statistical control charts provide a simple and very practical tool for looking at data, and assessing the robustness of the claim.
Data for daily new cases and deaths can be used to plot not only daily data but also calculate control lines for mean and 1, 2 and 3 sigma. This is done using a moving average. Moving average is baed on 7 days. A moving average is needed as a fixed boundary cannot be maintained. The moving average is based on 7 days, which appears to be a reasonable time period. Control limits signal that day-to-day variations in data are to be expected. It is about looking for trends in data, not the noise from daily variations.
Results are shown in figures below, with yellow circles showing the trend. It is evident that Austria display all the signs of having new cases under control, with daily count reducing day-on-day.
For comparison, Italy is also included. A similar trend can be observed in the data, with the mean number of daily new cases (and deaths) going down.