BuDS’ Covid-19 Predictions Proved Accurate

Every week, BuDS predicts the number of Covid-19 infected people in Buckinghamshire from official test data. We’ve checked our predictions against the official Office for National Statistics (ONS) Infection Survey and our predictions have been proven very accurate. Read on for more.

The Government collect and publish the number of people who choose to get tested for Covid-19, and then test positive. However, not everyone who has caught Covid-19 gets a test. Some people don’t realise they have Covid-19 because they have no or very mild symptoms, and some people decide not to have a test in case it means they have to stop work or give up a holiday. So, every week BuDS increases the number of people testing positive in Bucks to take account of the number who are positive but haven’t been tested. You can read more about this process in our full explanatory article here.

The Office for National Statistics (ONS) does an independent Infection Survey every week. This survey tests 50,000 people across England whether they are showing symptoms of Covid-19 or not. This ONS survey is the most accurate measure of the number of infected people because it doesn’t rely on people choosing to be tested.

To make sure that BuDS’ predicted number of infected people in Bucks is reliable, we have compared our predictions against the ONS Infection Survey results for the whole of the pandemic. The results are shown in the graph below.

Red line shows ONS Infection Survey results for the South East, adjusted for Buckinghamshire’s population
Blue line shows BuDS’ weekly predictions of the number of infected people in Buckinghamshire

The graph above shows that BuDS’ predictions (blue line) are close to the ONS data every week. This shows that our calculation method is reliable. BuDS usually predicts a smaller number of infected people than the ONS data shows, this proves that we are not exaggerating or overstating the issue as some people claim. Where BuDS’ predictions are significantly different from the ONS data, this is because the pandemic in Buckinghamshire is different to the pandemic across the South East.

More recently, the predicted totals and ONS survey have been very close together. The reason for this is not completely clear, but is probably because the pandemic in Buckinghamshire is now very similar to the pandemic across the South East – i.e. both locally and regionally, infection rates are going up very fast.

If you would like to know more about BuDS’ Covid-19 work, click here. All BuDS Covid-19 work is done by volunteers, and we welcome new members of the team. To express an interest or volunteer, click here.