Data universes and statistical traps

ONS analysis estimates Covid-19 death rates by vaccination status.

Statistics is the art of learning from data. The study encompasses data collection, management, analysis, interpretation, and communication.

Within this study, there are many pitfalls and traps. We should consider one analysis, and what it can — and cannot — show.

Start at the beginning

The Office for National Statistics analysed people in its Public Health Data Asset. Analysts calculated age-standardised mortality rates for deaths involving Covid-19, by vaccination status. These rates are for each month.

(Image: Office for National Statistics)

The ONS also provided an analysis of age-standardised mortality from other causes. The accompanying file included statistics on all-cause fatalities.

(Image: Office for National Statistics)

What is the Public Health Data Asset?

According to the methods note, this is a linked data set — with the 2011 census as its hub. Analysts link those records to General Practice and hospital episode data. Through NHS numbers, it also links to the immunisation system…