Fergus O'Dowd (Louth, Fine Gael)
Link to this: Individually | In context | Oireachtas source

289. To ask the Minister for Health if he will detail the reason for the excess mortality rates reported recently; and if he will make a statement on the matter. [10622/23]

Stephen Donnelly (Wicklow, Fianna Fail)
Link to this: Individually | In context | Oireachtas source

The Department of Health does not produce estimates of excess mortality. However, the Department works closely with the Health Protection Surveillance Centre (HPSC) and other stakeholders to monitor estimates of excess mortality.

Excess mortality refers to the number of deaths from all causes during a period of time above and beyond what we would have normally expected to see.

The Department closely monitors estimates of excess mortality which are published by a range of different sources.  A number of different methodologies have been developed by organisations and academics nationally and internationally to try to estimate levels of excess mortality and it should be noted that estimation methods vary widely, for example in the years used to estimate a baseline, how they estimate what are ‘expected’ deaths, the data source used for ‘actual deaths’ and whether statistical significance tests are applied. There is therefore no single source of data on estimated excess mortality.

The Health Protection Surveillance Centre (HPSC) has monitored excess mortality in Ireland since 2009, using registered deaths data reported to HPSC on a daily basis from the General Register Office (GRO). HPSC continues to participate in EuroMOMO for Ireland, a European mortality monitoring activity, aiming to detect and measure excess deaths related to seasonal influenza, pandemics and other public health threats. The HPSC provide an update on estimated excess mortality in their Weekly Influenza Surveillance Report.

The latest analysis of all registered deaths in Ireland up to 19 February 2023, using the standardised EuroMOMO algorithm has shown the following statistically significant excess mortality in December 2022 and January 2023: 

- Excess Pneumonia and Influenza mortality over four consecutive weeks (weeks 51 2022-2 2023), reaching moderate levels during week 52 2022 and week 1 2023.

- Low level excess all-cause mortality in all ages over three consecutive weeks (weeks 51 2022–week 1 2023). 

- Excess all-cause mortality in the ≥65-year age group over five consecutive weeks (weeks 50 2022-2 2023), reaching moderate levels during week 52 2022.

- Excess all-cause mortality in the 75-84-year age group over six consecutive weeks (weeks 49 2022-2 2023), reaching moderate levels during weeks 51 and 52 2022.

- Low level excess all-cause mortality in the ≥85-year age group over three consecutive weeks (weeks 51 2022-week 1 2023)

These data are provisional due to the time lag with death registrations in Ireland. This means data on excess mortality in recent months will continue to be updated as additional information becomes available. A country-specific adjustment function was applied to correct for the typical lag in registrations of deaths in Ireland (the legal period for death registration in Ireland is three months). Nonetheless, estimates of excess mortality for the most recent weeks are reported with some uncertainty and should be interpreted with caution.

HPSC anticipates that when further deaths are registered over the coming weeks, additional excess mortality for the 2022/2023 winter period will be observed. It is likely that this excess mortality will be observed for at least a 6-week period in December 2022 and January 2023.

It is important to note that excess mortality has been observed during previous periods when influenza viruses circulated at high levels in Ireland, for example in winter 2017/2018 which has previously been characterised as a severe flu season, and during certain periods of the COVID-19 pandemic.

As we have experienced a winter of high levels of influenza cases and hospitalisations, it would not be unexpected to see excess mortality. Influenza activity was at very high levels in Ireland during December 2022 and early/mid-January 2023, with a high number of influenza hospitalisations reported. Other important factors that may impact excess mortality include the ongoing COVID-19 pandemic, circulation of other respiratory viruses, impacts of cold weather, and an ageing population.

Excess mortality has also been observed in other European countries over the course of winter 2022/2023. In Europe, the overall pooled EuroMOMO estimates of all-cause excess mortality in all age groups for the participating European countries have shown elevated mortality in all age groups for late 2022/early 2023 with excess mortality declining recent weeks.

Separately, Eurostat publishes monthly estimates of excess mortality for EU (and some non-EU) countries. This data only incudes excess mortality estimates from January 2020 onwards. Eurostat use the following methodology, ‘The excess mortality indicator simply takes the number of people who died from any cause, in a given period, and compares it with a historical baseline from previous years in a period which was not affected by the pandemic. In this case, the baseline consists of the average number of deaths that occurred in each month during the period 2016-2019’.  The methodology does not require a statistically significant difference to report excess deaths.

In relation to data for Ireland, it is important to note that data from 2020 onwards is provided by the CSO based on a web-scraped series from rip.ie.  The comparison baseline (2016-2019) is built using official data on registered deaths. Caution is required in interpreting this indicator.

The latest data published by Eurostat (published 17 February 2023), refers to deaths in December 2022.  Eurostat estimates that the EU (25) experienced additional deaths of 19% above baseline. It is estimated that Ireland experienced 25.4% additional deaths.  Across Europe, the countries with the highest estimated additional deaths in December were Iceland (43.1%), Germany (37.3%) and Austria (27.4%).

The Central Statistics Office (CSO) publishes official statistics on mortality in Ireland and publishes quarterly and yearly statistics on registered deaths through their Vital Statistics publications. The latest published data is for Quarter 2 2022 and data is provisional. Provisional data for deaths registered in Quarter 3 2022 will be published in March and for deaths registered in Quarter 4 2022 in June. This will include data on cause of death and allow more detailed analysis of mortality trends in this period.

The Department of Health is actively monitoring and reviewing all available data on mortality as it becomes available.