Excess mortality in North West - 21 March 2020 to to 05 February 2021

Introduction

Monitoring excess mortality provides understanding of the impact of COVID-19 during the course of the pandemic and beyond. Excess mortality in this report is defined as the number of deaths throughout the pandemic which are above the number expected based on mortality rates in earlier years.

In this report the expected number of deaths is modelled using five years of data from preceding years to estimate the number of deaths we would expect on each week through the pandemic. Excess deaths are estimated by week and in total since 21 March 2020, based on the date each death was registered rather than when it occurred. Excess deaths are presented by age, sex, Upper Tier Local Authority, ethnic group, level of deprivation, cause of death and place of death. Please note, some of the figures in this report have been rounded, though the differences displayed are based on unrounded data.

All Persons

Weekly excess deaths by date of registration, North West.&lrm;

Figure 1: Weekly excess deaths by date of registration, North West.‎

The trend in total excess deaths by week, in North West, since week ending 27 March 2020 is shown in Figure 1. Numbers above each of the columns show the total number of excess deaths and how these compare with the expected number based on modelled estimates for 2015 to 2019. For example, in week ending 24 April 2020 there were 1,561 excess deaths and this was over two times (2.01 times higher) the expected number of deaths in this week. When fewer deaths than expected occur in a week, the column is coloured grey.

Excess deaths where COVID-19 was mentioned on the death certificate are shown in orange. If the number of deaths is not shown in the orange part of the column, that means the total excess was less than the number of deaths with a mention of COVID-19, indicating fewer deaths from other causes than expected in these weeks.

The number of excess deaths without COVID-19 mentioned on the certificate (shown in the white part of the column) may be due to an increase in deaths from other causes during the period of the pandemic but may also reflect under-reporting of deaths involving COVID-19.

Figure 2: Cumulative deaths since 21 March 2020, by date of registration, North West.

The trend in the total cumulative number of excess deaths in North West since 21 March 2020 is shown in Figure 2.

Age Group Males

Figure 3: Cumulative excess deaths (A) and the ratio of registered deaths to expected deaths (B) by age group, males, North West.

Figure 3A for males can be used to compare the cumulative total of excess deaths since 21 March 2020 between age groups.

Figure 3B compares the cumulative total of excess deaths among males with the number which would have been expected based on the modelled estimates for earlier years. Where the ratio of observed to expected is negative, this is shown in grey. The proportion of the excess where COVID-19 was mentioned on the death certificate is shown in yellow.

Table 1 - Males

Age group (years)	Registered deaths	Expected deaths	Ratio registered / expected	Excess deaths	COVID-19 deaths	COVID-19 deaths as % excess
0-14	200	241	-^*	−41	0	-
15-44	1,204	1,071	1.12	133	104	78.1%
45-64	6,283	4,321	1.45	1,962	1,059	54.0%
65-74	8,007	6,114	1.31	1,893	1,836	97.0%
75-84	12,522	9,910	1.26	2,612	3,568	>100%⁺
85+	11,067	9,524	1.16	1,543	3,154	>100%⁺
^* registered deaths were not significantly different from expected deaths for the time period ⁺ the total excess was less than the number of deaths with a mention of COVID-19, indicating fewer deaths from other causes than expected

Why ratios are important

Ratios can be useful for comparing between groups when the expected number is very different between groups.

For example, if group A had 5 excess deaths and group B had 10, it could appear that the impact was twice as high in group B. However, if the expected number of deaths was 1 in group A and 5 in group B, and the registered numbers of deaths were 6 and 15 respectively, then the ratios would show that group A experienced 6 times the number of deaths compared to expected, while group B experienced 3 times the number expected. Therefore, the actual relative impact is higher in group A.

The ratios presented in this report are relative to historical trends within each group, and not in relation to another group. For example, in the ethnicity section the ratio for the Asian group is the ratio between deaths in this group registered in 2020 and the estimate of expected deaths in the Asian group based on the preceding 5 years. It is not the ratio between the Asian group and another ethnic group.

Age Group Females

Figure 4: Cumulative excess deaths (A) and the ratio of registered deaths to expected deaths (B) by age group, females, North West.

Figure 4A for females can be used to compare the cumulative total of excess deaths since 21 March 2020 between age groups.

Figure 4B shows the ratio of the observed to the expected deaths by age group among females since 21 March 2020. This chart can be used to compare the relative excess mortality between age groups.

Table 2 - Females

Age group (years)	Registered deaths	Expected deaths	Ratio registered / expected	Excess deaths	COVID-19 deaths	COVID-19 deaths as % excess
0-14	168	188	-^*	−20	0	-
15-44	749	591	1.27	158	73	46.2%
45-64	3,951	2,945	1.34	1,006	639	63.5%
65-74	5,608	4,295	1.31	1,313	1,135	86.4%
75-84	10,711	8,624	1.24	2,087	2,527	>100%⁺
85+	16,481	14,403	1.14	2,078	3,725	>100%⁺
^* registered deaths were not significantly different from expected deaths for the time period ⁺ the total excess was less than the number of deaths with a mention of COVID-19, indicating fewer deaths from other causes than expected

Ethnic Group Males

Figure 5: Cumulative excess deaths (A) and the ratio of registered deaths to expected deaths (B) by ethnic group, males, North West.

Figure 5A for males can be used to compare the cumulative total of excess deaths since 21 March 2020 between ethnic groups.

Figure 5B shows the ratio of the observed to the expected deaths by ethnic group among males since 21 March 2020. This chart can be used to compare relative excess mortality between ethnic groups.

Table 3 - Males

Ethnic group	Registered deaths	Expected deaths	Ratio registered / expected	Excess deaths	COVID-19 deaths	COVID-19 deaths as % excess
Asian	1,124	645	1.74	480	484	>100%^*
Black	361	200	1.80	160	121	75.4%
Mixed	115	90	-⁺	25	30	>100%^*
Other	239	189	1.26	50	65	>100%^*
White	36,359	29,243	1.24	7,117	8,590	>100%^*
^* the total excess was less than the number of deaths with a mention of COVID-19, indicating fewer deaths from other causes than expected ⁺ registered deaths were not significantly different from expected deaths for the time period

Ethnic Group Females

Figure 6: Cumulative excess deaths (A) and the ratio of registered deaths to expected deaths (B) by ethnic group, females, North West.

Figure 6A for females can be used to compare the cumulative total of excess deaths since 21 March 2020 between ethnic groups.

Figure 6B shows the ratio of the observed to the expected deaths by ethnic group among females since 21 March 2020. This chart can be used to compare relative excess mortality between ethnic groups.

Table 4 - Females

Ethnic group	Registered deaths	Expected deaths	Ratio registered / expected	Excess deaths	COVID-19 deaths	COVID-19 deaths as % excess
Asian	772	478	1.61	294	277	94.3%
Black	241	140	1.72	101	64	63.0%
Mixed	97	70	-^*	26	13	51.1%
Other	167	107	1.56	60	37	62.1%
White	35,310	29,469	1.20	5,841	7,268	>100%⁺
^* registered deaths were not significantly different from expected deaths for the time period ⁺ the total excess was less than the number of deaths with a mention of COVID-19, indicating fewer deaths from other causes than expected

Ethnicity coding

Ethnicity is not collected at death registration, so these estimates were made by linking death records to hospital records to find the ethnicity of the deceased. This approach has some limitations. Ethnicity is supposed to be self-reported by the patient in hospital records, but this may not always be the case. Patients may also report different ethnicities in different episodes of care. For this analysis the most recent reported ethnic group was used. Population estimates have been used to calculate mortality rates to estimate the expected numbers of deaths, and these were based on the 2011 Census. This may lead to a mismatch between ethnicity reported in hospital records and self-reported ethnicity in the census. It appears, for example, that more people are assigned to the ‘Other’ group in hospital records than in the 2011 Census.

Deprivation

Figure 7: Cumulative excess deaths (A) and the ratio of registered deaths to expected deaths (B) by deprivation quintile, North West.

Figure 7A can be used to compare the cumulative total of excess deaths since 21 March 2020 between deprivation quintiles.

Figure 7B shows the ratio of the observed to the expected deaths by deprivation quintile since 21 March 2020. This chart can be used to compare relative excess mortality between deprivation quintiles.

Table 5

Deprivation quintile	Registered deaths	Expected deaths	Ratio registered / expected	Excess deaths	COVID-19 deaths	COVID-19 deaths as % excess
Quintile 1 - Most Deprived	27,583	21,255	1.30	6,328	6,413	>100%^*
Quintile 2	14,791	11,826	1.25	2,965	3,622	>100%^*
Quintile 3	11,435	9,543	1.20	1,892	2,592	>100%^*
Quintile 4	12,898	10,937	1.18	1,961	2,982	>100%^*
Quintile 5 - Least Deprived	10,244	8,684	1.18	1,560	2,211	>100%^*
^* the total excess was less than the number of deaths with a mention of COVID-19, indicating fewer deaths from other causes than expected

Upper Tier Local Authority

Figure 8: Cumulative excess deaths (A) and the ratio of registered deaths to expected deaths (B) by Upper Tier Local Authority, North West.

Figure 8A can be used to compare the cumulative total of excess deaths since 21 March 2020 between Upper Tier Local Authorities.

Figure 8B shows the ratio of the observed to the expected deaths by Upper Tier Local Authority since 21 March 2020. This chart can be used to compare relative excess mortality between Upper Tier Local Authorities.

Table 6

Upper Tier Local Authority	Registered deaths	Expected deaths	Ratio registered / expected	Excess deaths	COVID-19 deaths	COVID-19 deaths as % excess
Blackburn with Darwen	1,448	1,104	1.31	344	399	>100%^*
Blackpool	1,901	1,579	1.20	322	411	>100%^*
Bolton	2,831	2,250	1.26	581	687	>100%^*
Bury	2,050	1,568	1.31	482	518	>100%^*
Cheshire East	4,079	3,541	1.15	538	920	>100%^*
Cheshire West and Chester	3,589	3,017	1.19	572	844	>100%^*
Cumbria	6,166	4,884	1.26	1,282	1,270	99.1%
Halton	1,238	1,079	1.15	159	262	>100%^*
Knowsley	1,685	1,359	1.24	326	353	>100%^*
Lancashire	13,435	11,013	1.22	2,422	2,918	>100%^*
Liverpool	5,072	3,862	1.31	1,210	1,262	>100%^*
Manchester	3,843	2,953	1.30	890	895	>100%^*
Oldham	2,288	1,836	1.25	452	639	>100%^*
Rochdale	2,274	1,755	1.30	519	583	>100%^*
Salford	2,361	1,871	1.26	490	593	>100%^*
Sefton	3,650	2,825	1.29	825	752	91.2%
St. Helens	2,054	1,723	1.19	331	438	>100%^*
Stockport	2,912	2,448	1.19	464	645	>100%^*
Tameside	2,491	2,014	1.24	477	658	>100%^*
Trafford	2,083	1,745	1.19	338	470	>100%^*
Warrington	2,071	1,748	1.18	323	509	>100%^*
Wigan	3,470	2,871	1.21	599	933	>100%^*
Wirral	3,960	3,181	1.24	779	861	>100%^*
^* the total excess was less than the number of deaths with a mention of COVID-19, indicating fewer deaths from other causes than expected

Deaths by underlying cause

See ICD10 references for the details of the ICD10 codes for each cause in this section.

$Cumulative excess deaths (A) and the ratio of registered deaths to expected deaths (B) by underlying cause of death, North West.$

Figure 9: Cumulative excess deaths (A) and the ratio of registered deaths to expected deaths (B) by underlying cause of death, North West.

Figure 9A shows the total cumulative excess deaths by UCOD since 21 March 2020. The chart can be used to compare the number of excess deaths for each UCOD.

This chart can be used to compare the cumulative total of excess deaths since 21 March 2020 between underlying causes.

Figure 9B shows the ratio of the observed to the expected deaths by UCOD since 21 March 2020. This chart can be used to compare relative excess mortality between underlying causes of death.

Table 7

Underlying cause of death	Registered deaths	Expected deaths	Ratio registered / expected	Excess deaths	COVID-19 deaths	COVID-19 deaths as % excess
Ischaemic Heart Diseases	6,828	6,496	1.05	332	216	65.1%
Cerebrovascular Diseases	3,321	3,120	1.06	201	150	74.5%
Other Circulatory Diseases	4,732	4,679	-^*	53	144	>100%⁺
Cancer	16,866	17,215	-^*	−349	484	-
Acute Respiratory Infections	2,598	3,304	0.79	−706	2	-
Chronic Lower Respiratory Diseases	3,475	4,153	0.84	−678	94	-
Other Respiratory Diseases	986	1,423	0.69	−437	22	-
Dementia and Alzheimer's	8,103	8,183	-^*	−80	339	-
Diseases of the Urinary System	949	875	-^*	74	56	75.3%
Cirrhosis and Other Liver Diseases	1,408	1,310	-^*	98	68	69.6%
Parkinson's Disease	683	749	-^*	−66	31	-
All Other Causes (Excl. COVID-19)	11,048	10,764	-^*	284	260	91.6%
^* registered deaths were not significantly different from expected deaths for the time period ⁺ the total excess was less than the number of deaths with a mention of COVID-19, indicating fewer deaths from other causes than expected

Place of Death

Figure 10: Cumulative excess deaths (A) and the ratio of registered deaths to expected deaths (B), by place of death, North West.

Figure 10A shows the total cumulative excess deaths in each place of death since 21 March 2020. The chart can be used to compare the numbers of excess deaths in each place of death. This chart can be used to compare the cumulative total of excess deaths since 21 March 2020 between places of death.

Figure 10B shows the ratio of the observed to the expected deaths in each place of death since 21 March 2020. This chart can be used to compare relative excess mortality between places of death.

Table 8

Place of death	Registered deaths	Expected deaths	Ratio registered / expected	Excess deaths	COVID-19 deaths	COVID-19 deaths as % excess
Care Home (Nursing or Residential)	16,427	12,838	1.28	3,589	3,698	>100%^*
Home	20,830	15,273	1.36	5,557	818	14.7%
Hospice	2,705	3,681	0.73	−976	204	-
Hospital (Acute or Community, not Psychiatric)	35,328	28,971	1.22	6,357	13,017	>100%^*
Other Places	1,661	1,432	1.16	229	83	36.2%
^* the total excess was less than the number of deaths with a mention of COVID-19, indicating fewer deaths from other causes than expected

Comparisons to other measures of excess deaths in England

The Office for National Statistics also publishes a weekly report on excess deaths in England & Wales. The numbers reported by ONS are broadly in line with the overall excess death figures in this report but there are some differences as the ‘expected’ numbers in this report are not just the simple five-year average for 2015 to 2019, as used by ONS. As explained in the Methods, they are instead modelled estimates which adjust for factors such as the ageing of the population and the underlying trend in mortality rates from year to year.

EuroMOMO is a European mortality monitoring programme that aims to measure excess deaths related to seasonal influenza and other public health threats that uses a standardised methodology across 24 European countries. The methodology used by EuroMOMO is similar to that used by the PHE model, however, the EuroMOMO model looks at deaths by date of occurrence, and the PHE model looks at deaths by date of registration. Because there is a time lag between date of occurrence of death and date of registration, analysis of excess deaths by date of occurrence requires a delay correction, the reliability of which improves over time. These two models produce very similar results but with small differences due to the delay correction applied by EuroMOMO.

The PHE Daily GRO mortality model is used in PHE’s COVID-19 surveillance report for all-cause mortality. It uses a 5-year average to estimate expected deaths, similar to that used by the ONS but with a trend included. It looks at deaths by date of occurrence based on rapidly reported deaths from the General Register Office and uses a registration delay correction, the reliability of which improves over time. Overall, the excess deaths are similar in the COVID-19 surveillance report and this report, but may show some differences in specific weeks due to use of occurrence date compared with registration date, and in recent weeks due to the delay corrections.

Updates to Excess Mortality Methodology, December 2020

Several changes to the models were introduced in the regional report from January 2020:

Estimates are modelled on weekly periods, rather than modelled on daily periods and aggregated to weeks for publication
Weeks begin on Saturday and end on Friday, rather than Sunday to Saturday. This is consistent with ONS reporting weeks
The ONS Annual Death Extract is used as the source for 2019 deaths, instead of the previous (provisional) weekly data from the Mortality & Births Information System (MBIS)
2019 mid-year population estimates are now used instead of 2019 population projections
The model now includes additional interaction terms for age and time of year (seasonality), age and deprivation, and age and ethnic group

The methodology document has been updated to reflect these changes.

Links to historic reports

ICD10 references

Cause description	ICD10 reference
Ischaemic heart diseases	Underlying cause of death is between I20-I25
Cerebrovascular diseases	Underlying cause of death is between I60-I69
Other circulatory diseases	Underlying cause of death begins with I (excluding I20-I25 and I60-I69)
Cancer	Underlying cause of death is between C00-C97
Acute respiratory infections	Underlying cause of death is between J00-J22
Chronic lower respiratory diseases	Underlying cause of death is between J40-J47
Other respiratory diseases	Underlying cause of death begins with J (excluding J00-J22 and J40-J47)
Dementia and Alzheimer’s	Underlying cause of death is one of F01, F03, or G30
Diseases of the urinary system	Underlying cause of death is between N00-N39
Cirrhosis and other liver diseases	Underlying cause of death is between K70-K76
Parkinson’s disease	Underlying cause of death is G20
All other causes (excl. COVID-19)	All other underlying causes of death (excluding COVID-19)