Throughout this report, counts of deaths are compared to an average number of deaths for previous years. In this report, data for 2021 is compared to an average number of deaths recorded over the 5 years from 2015-2019 as was the case in previous publications. Data for 2022 is compared to a baseline comprising the years 2017-2019 and 2021. 2020 is not included in the baseline for 2022 data because it included periods where numbers of deaths were significantly lower than expected. Counts of deaths for 2015-2021 are included in the baseline datacubes of the data downloads section of this report.
These average or baseline counts serve as a proxy for the expected number of deaths, so comparisons against baseline counts can provide an indication of whether mortality is higher or lower than expected in a given year. The minimum and maximum counts are also included to provide an indication of the range of previous counts. Minimums and maximums for any given week can be from any of the years included in the baseline.
While this publication can provide an indication of where counts of deaths are above or below expectations, it does not provide official estimates of excess mortality. Using the number of deaths from the previous years as the predictor for the expected number of deaths does not take into account changes in population size and age-structures of that population, as well as expected improvements in mortality rates over time. Age-standardised death rates can be accessed via the data downloads tab in this publication.