Tackling UK’s mortality problem: covid-19 and other causesBMJ 2020; 369 doi: https://doi.org/10.1136/bmj.m2295 (Published 11 June 2020) Cite this as: BMJ 2020;369:m2295
All rapid responses
The relationship between delays in lock-down and excess mortality (Re: Tackling UK’s mortality problem: covid-19 and other causes)
The author spotlights excess mortality arising as a result of the Covid-19 pandemic, and the need to identify reasons for this. Governments throughout the world have adopted a range of different responses to the crisis, and this has created a natural experiment which could shed light on this, and thereby enable the world to cope more effectively with any future pandemic.
I hypothesised that the efficiency with which governments responded to the impending Covid-19 pandemic had a major effect on its impact on their populations. I therefore undertook a comparative study of the relative performance of European governments in tackling the pandemic. A measure of the alacrity with which governments is provided by the speed with which they imposed lock-downs following the first confirmed case in each country. This was calculated as the number of days incorporating the date of the first case and the date of lock-down, and the interval in between, and correlated with a measure of excess mortality.
Excess mortality compared with the same period last year was selected in preference to mortality due to Covid-19, as this latter measure depends not only on numbers of deaths but also on the availability of testing facilities. Excess mortality was calculated for each country by enumerating numbers of excess deaths over observation periods that extended from the date of the first case to either the end of May or the first week of June, and then expressed as the average excess deaths per week per million population. The disadvantage of this approach was that a number of governments that responded rapidly to the challenge of Covid-19 and where outcomes appeared excellent, including Greece, Albania and Slovakia, were excluded from the analysis because I could find no data on excess mortality.
Country-specific data on date of first case, observation period and numbers of excess deaths were obtained from the 'Our World in Data' website, while lock-down dates were obtained from Wikipedia. Overall, sixteen countries were included in the analysis, including the four home countries. The correlation coefficient (R) between number of days to lock-down and excess mortality was 0.89, so that the variation in excess mortality explained by delay in lock-down (R squared) was 79.4%.
Delay in lock-down thus appeared a major factor affecting excess mortality during the Covid-19 pandemic. These results must be regarded as provisional, though, because observation periods differed in duration as a result of differences in dates of first cases, and because different countries were at different stages in the course of the pandemic. My intention is therefore to repeat this analysis when the pandemic is over.
Competing interests: No competing interests