A pandemic primer on excess mortality statistics and their comparability across countries
A pandemic primer by Janine Aron and John Muellbauer, members of the Leverhulme Centre for Demographic Science, University of Oxford, with Charlie Giattino and Hannah Ritchie, examines excess mortality statistics and their comparability across countries. Excess mortality data avoid miscounting deaths from the under-reporting of Covid-19-related deaths and other health conditions left untreated. Excess mortality is defined as actual deaths from all causes, minus ‘normal’ deaths. The article assesses the comparability of data on excess mortality between countries and regions, it reviews the available data sources, and compares and contrasts different statistical measures of excess mortality. Now that the first wave of the pandemic is over for most European countries, it is a timely moment for robust European comparisons.
The Leverhulme Centre for Demographic Science has several projects working on excess mortality. A recent pre-print by several members of LCDS led by Jose Manuel Aburto and Ridhi Kashyap estimated the burden of Covid-19 on mortality, life expectancy and lifespan inequality in England and Wales, available here.
Aron and Muellbauer’s preferred measure of excess deaths relative to normal deaths, the transparent and comparable P-score, is calculated for European countries with high rates of excess mortality during the Covid-19 pandemic. For the ‘all age’ group and especially for the working age group, ‘15-64’, England has had the highest rates of excess mortality. Spain had the highest cumulative P-score over the pandemic weeks for the ‘over 85’ age group. The article addresses issues of international data and comparability on the extent of deaths among the care home residents. It proposes modellers should have ready access to transparent, comparable international data to a granular level to test hypotheses to aid policy making for potential further waves of the pandemic. The authors also suggest how international statistical agencies and national statistical agencies could publish improved measures of excess mortality.
The publication can be read in full here. BBC Economics Editor Faisal Islam reported on the research in articles on 29 June and 4 July, with findings also outlined on BBC Radio 4 News, 6pm 29th June (listen from 8min 17secs).
Figure 2. Peak of the first wave of the pandemic occurred earlier than when registrations were recorded: contrasting ‘all age’ excess mortality P-scores for England by registration or occurrence data
Sources: ONS, UK