Situation
I have been away for two weeks in East Tennessee, when I drove back to Nashville on Thursday evening. I was struck by how light traffic was in downtown. On Friday morning my daughter's school notified us that after spring break they are suspending in person classes and shifting to online distance learning mode for two weeks. People were leaving grocery store with $600-$700 shopping bills (Yes Kroger had limited toilet paper to 3 rolls per shopper).
Reaction
My initial reaction was that the authorities and people were over reacting. I was thinking of the economic damage voluntary or involuntary 'lock downs' may cause. I also wasn't sure if we had enough data to justify these actions. So I decided to dig into the data.
The Data Set
I created a simple data set from daily 2 pm Tweets of TN Department of Health that shows number of total cases in TN and cases in Williamson and Davidson counties that make the bulk of Nashville area population. This data set is shown below.
Data Analysis
First thing that struck me is why are we not publishing the data graphically? A simple line chart or a bar chart over time would go a long way. It will tell us the relative magnitude of the cases in different counties. It will also tell if the pace of new infections detected was increasing or decreasing. The chart below shows Total TN cases and cases in Williamson and Davidson counties over the last 1 week or so.
As we can see from the chart above, the slope (or change per day in number of cases) is increasing, in both TN as a whole and Davidson in particular. The data for Willliamson seems to indicate a stable if not flattening curve. Another was to look at data is to plot change in number of cases (or new cases) per day and the trend becomes even more clear.
Takeaways
Time and again I found it much more useful to see data as a time series and not individual pieces of data. When you look at increasing pace of COVID-19 infections, I am no longer in doubt that pretty dramatic measures have to be taken to prevent the spread of COVID-19 Virus. These may include closure of schools, public events, travel restrictions, work from home, practicing healthy hygiene etc. etc.. Irrespective of how we got here it is more important to focus on what we can do in the future.(Note: These are my personal views and do not represent the views of my employer)
