Mortality

Mortality overview

Assessing the number and rate of deaths (or mortality) in any population is important in understanding and monitoring the health status of a whole community. Understanding the underlying causes of mortality, the prevalence and trends in premature (deaths before 75 years of age) and preventable mortality (causes of death that can be mainly avoided through effective public health and primary prevention interventions) are particularly important, with preventable mortality being a priority area in the Southampton 2017-25 Health and Wellbeing Strategy.

In the UK, deaths must be reported to the Local Registration Service, in partnership with the General Register Office (GRO). This is a legal requirement as set out in the Births and Deaths Registration Act (1836). The coding used for cause of death is carried out according to the World Health Organization (WHO) International Classification of Diseases (ICD-10) and internationally agreed rules, allowing for international comparisons.

Numbers of deaths represent the number of registered deaths in a population but, because there can be registration delays including those deaths requiring a coroner’s verdict, deaths by date of registration may include deaths that occurred months or even years earlier. Deaths for Southampton include resident deaths that occur outside Southampton.

Mortality in Southampton

In 2020, there were 2,011 deaths registered in Southampton. Over the last three years (2018-20), mortality from all causes was 5,713 deaths. This is a directly age standardised rate (DSR) of 1,038 deaths per 100,000 population, which is significantly worse than the national average of 973 per 100,000 population. Southampton has the 7th highest mortality rate amongst its ONS comparator group.

Large differences are seen between males and females. The local DSR of 1,238 per 100,000 population for males, which is significantly worse than nationally (1,138 DSR per 100,000 population) and 6th highest among our ONS comparator group (12 local authorities). For females, in Southampton, the DSR was 879 per 100,000 population, which is significantly worse than the national average (838 DSR per 100,000 population) and 8th highest among our ONS comparator group.

Between 2001-2003 and 2009-2011, the mortality rate had been decreasing slightly faster in Southampton than nationally. However, since 2009-2011, the national rate has continued to decrease whilst the Southampton rate has increased. Both nationally and in Southampton, a rise was seen in mortality from 2017-2019 to 2018-2020. This is likely due to the start of the COVID-19 pandemic with the trend expected to continue as further data is released for the COVID-19 pandemic period. More information on the impact of COVID-19 can be found in the COVID-19 impact assessment.

Mortality varies at a local level from a rate of 798 DSR per 100,000 population in Bitterne Park ward to 1,521 DSR per 100,000 population in Woolston ward. The following sections illustrate how mortality varies by age and deprivation.

More information can be found in the dashboard below and in resources section at the bottom of the page.

Mortality by age

In Southampton, in 2018-20 (pooled), the number of stillbirths (those infants that died in the womb after having survived through at least the first 24 weeks of pregnancy) was 5.4 per 1,000 births, which is significantly worse than the national average (3.9 per 1,000 births). Over the last three recent data periods the local rate has plateaued whilst the national rate has been falling. The recent Southampton rate is the highest among its ONS comparator group.

The neonatal mortality rate for Southampton, in the same period, was 4.0 per 1,000 births, which is higher than the national average (2.8 per 1,000 births) and the highest among ONS comparators. The post-neonatal mortality rate (deaths between 28 days and 1 year) for Southampton, for the same period, was a crude rate of 0.8 per 1,000 births, which is lower than the national rate (1.1 per 1,000 births), although not statistically significantly so. This is the 4th lowest amongst the ONS comparator group.

Infant mortality in Southampton has increased from 2.8 per 1,000 births in 2012-14 to 4.8 per 1,000 births in 2018-20. In comparison, the national average has remained consistent between 3.9 and 4.0 per 1,000 births over the same period. In 2008-10, the infant mortality rate in Southampton is higher than the England average, ONS comparators and local neighbours (Hampshire and Isle of Wight), although not statistically significantly so.

The all cause child mortality rate (deaths of a child between the age of 1 and 17 years) in Southampton in 2018-20 was 10.1 DSR per 100,000 persons, which is lower than the England average (10.3 per DSR per 100,000 persons), although not statistically significantly so. Southampton is mid-rank among its ONS comparator group. The national rate has decreased at a faster rate than in Southampton since 2010-12.

In Southampton, 16.9% of (all cause) mortality occurs in those aged under 65 years, which is higher than the national average of 15.0%. 17.5% of deaths occur in the 65 to 74 age group in the city compared to the national average (16.2%). It is a similar picture for those aged 75 to 84 years, where 27.9% of deaths occur in the city, compared to 28.8% nationally. The proportion of deaths occurring in those aged 85 years and over is significantly lower in Southampton (37.0%) compared to the national average (40.0%). This is likely to reflect Southampton’s younger population.

Hospitals remain the most common place of death across all age groups (39.2% of all deaths) except for those aged 85 and over where it is care homes (37.5%).

Mortality by deprivation

Within the city, mortality rates are statistically significantly higher in the 20% most deprived areas of Southampton (1,194 DSR per 100,000) compared to the 20% least deprived areas (724 DSR per 100,000). Amongst males in the city, mortality in the 20% most deprived areas is 1.8 times higher than in the 20% least deprived areas (1,427 compared with 773 DSR per 100,000). Amongst females, mortality rates are 1.4 times higher in the 20% most deprived areas (1,014 compared to 701 DSR per 100,000).

Under 75 mortality is 2.4 times higher in the 20% most deprived areas in Southampton compared to the 20% least deprived (527 compared to 219 DSR per 100,000). For males this increases to a difference of 3.7 times higher (625 compared to 168 DSR per 100,000), whilst for females the difference is 1.6 times higher (432 compared to 269 DSR per 100,000).

Underlying causes of mortality

The underlying cause of death is most often used to understand more about patterns and trends in mortality among a particular population. The underlying cause of death is defined by the World Health Organization as “the disease or injury which initiated the train of morbid events leading directly to death, or the circumstances of the accident or violence which produced the fatal injury”.

When looking at deaths grouped by underlying cause in Southampton for 2020 it was found that:

• The three main causes were:
  • Cancer - 518 deaths (25.8%)
  • Circulatory diseases - 453 deaths (22.5%)
  • Respiratory diseases - 235 deaths (11.7%)
• Lung cancer accounted for 1 in 15 of all deaths, the most of all cancers (120 deaths)
• 42.8% of circulatory disease deaths was caused by Ischaemic heart diseases (194 deaths)
• 49.8% of all respiratory disease deaths was attributed to other COPD (117 deaths)
• COVID-19 was responsible for 8.7% deaths in 2020 (173 deaths)

The Office for Health Improvement and Disparities (OHID) have produced an inequalities segment tool which shows the relative contribution that nine broad causes of death have on the gap between life expectancy for Southampton and that for England for the 2020 to 2021 period (the data is provisional). Circulatory disease (20.5%) cancer (19.7%) and respiratory (19.2%) deaths are the largest groups contributing to the gap in male life expectancy compared to England. On closer inspection, the two largest causes are chronic lower respiratory disease followed by heart disease.

For females, circulatory disease (24.6%) is also the largest group contributing to the gap in female life expectancy compared to England, with respiratory diseases (23.6%), other causes (14.9%) and external causes (10.5%) also contributing. Cancer only contributed 3.5% to the gap for females, unlike for males where it was over 5 times higher. More detailed analysis shows the single largest cause of the gap in female life expectancy is chronic lower respiratory diseases followed by other and lung cancer. COVID-19 contributed 4.3% to the gap in male life expectancy and 4.2% to the gap for females.

Preventable Mortality

Preventable mortality is defined as causes of death that can be mainly avoided through effective public health and primary prevention interventions (for example improvement of healthy behaviours to reduce the chance of disease).

In Southampton, under 75 mortality from causes considered preventable, was 189 DSR per 100,000 population in the period 2017-19 (pooled). This is statistically significantly worse than the national average (142 DSR per 100,000 population) and the 4th highest among our Office for National Statistics comparators, behind Liverpool (229), Newcastle upon Tyne (199) and Portsmouth (192). The rate for males and females is also significantly worse than the national average, with both rates the 4th highest amongst the ONS comparator group. For males in Southampton the rate is 241 DSR per 100,000, compared to 189 DSR per 100,000 nationally. For females the rate in Southampton is 138 DSR per 100,000 compared to 98 DSR per 100,000 nationally.

The national trend has seen a decrease from 192 DSR per 100,000 persons in 2001-03 to 142 DSR per 100,000 persons in 2017-19 (pooled). Although the Southampton trend decreased at a similar rate to the national average, reaching a low of 181 DSR per 100,000 persons in 2014-16, the rate since then has increased once more to 189 DSR per 100,000 in 2017-19.

Within the city, there is substantial variation at a ward level. The preventable mortality rate for Bevois is 300 DSR per 100,000 persons, which is 1.6 times higher than the city average, and significantly higher than Bassett which has the lowest preventable mortality at 105 DSR per 100,000 for the period 2018-20 (pooled). There is also significant variation between those living in the 20% most deprived areas and those living in the 20% least deprived areas, with the former experiencing preventable mortality rates 4.3 times higher compared to the latter (264 compared to 61 DSR per 100,000).

Years of life lost

Not only is it important to consider the number of deaths from each underlying cause, but also the impact of each death. One way of measuring this is through calculating the number of life years lost.

Years of life lost (YLL) is a measure of the average time a person would have lived had they not died before the age of 75 years. This data helps measure the social and economic loss from dying younger and highlights the specific causes of death affecting younger people such as suicide and accidents.

Between 2018 and 2020, nearly 30,200 years of life were lost for Southampton residents aged under 75 years. During this period:

• Cancer (27.8% of YLL), circulatory diseases (17.7% of YLL) and respiratory diseases (6.3% of YLL) together accounted for over half of all years of life lost
• 8,384 years of life were lost due to cancer. The two highest contributing types of cancer were:
  • Lung cancer – 1,665 years of life lost (19.9% of years lost to cancer deaths)
  • Breast cancer - 927 years of life lost (11.1% of years lost to cancer deaths)
• 5,358 years of life were lost due to circulatory diseases. The highest contributing type was:
  • Coronary heart disease - 2,756 years of life lost (51.4% years lost to circulatory disease deaths)
• 2,271 years of life were lost due to suicide (and injury undetermined)
• 1,890 years of life were lost due to respiratory diseases

More information on causes of mortality and years of life lost can be found in the resources section below, whilst analyses of the causes of mortality which contribute most to inequalities in life expectancy in Southampton can be seen in the life expectancy and health inequalities pages.

Excess winter deaths

Excess winter deaths are estimated by comparing the four winter months: December to March with the average of the four-month periods before and after. In England, an estimated 27,330 excess winter deaths occurred in England and Wales in winter 2019 to 2020, which was 17.2% higher than winter 2018 to 2019.

The number of excess winter deaths depends on the temperature and the level of disease in the population as well as other factors, such as how well equipped people are to cope with the drop in temperature. Most excess winter deaths are due to circulatory and respiratory diseases, and the majority occur amongst the elderly population.

The excess winter mortality index (which is used to compare between sexes, age groups and geographical areas) in England was statistically significantly higher than for winter 2018 to 2019, but statistically significantly lower than the 2016 to 2017 and 2017 to 2018 winters.

Overall, the excess winter mortality index in 2019 to 2020 was higher for males than females, conversely compared to previous years. The most recent period, males excess winter mortality exceeding females, which was the first time since 1994 to 1995 for England. Those aged 90 years and over continued to have the highest index score in England.

Respiratory diseases continued to be the leading cause of excess winter deaths that occurred in 2019 to 2020.

In the excess winter death index, Southampton had an estimated 40 (7.4%) excess winter deaths, all ages, occurred in the winter 2019 to 2020. This is lower compared with 17.4% in England and 10 of Southampton’s ONS comparators where the highest was 24.3% in Coventry. In Southampton there was a fall of -50 deaths between 2018 to 2019, (90 deaths or 15.4%) and 2019 and 2020 (40 deaths or 7.4%).

In Southampton’s wards, between 2018 to 2021 (3 years pooled) Harefield (35.7%) and Peartree (35.6%) have the highest levels of excess winter deaths. This is compared to 12.2% in Southampton over the same period and -11.7% in Freemantle, a negative number means there are fewer winter deaths than summer ones.

Looking at sub-city deprivation, at national quintiles, between 2018 to 2021 (3 years pooled), excess winter deaths were highest in the 3rd quintile (24.5%) and 15.8% in the 20% least deprived areas. The 20% most deprived areas had a rate of 10.5%.

For those aged 85 and over, for the period 2019 to 2020, there were estimated to be 20 (7.0%) excess winter deaths. Compared with 20.8% in England. Southampton is ranked second lowest compared to its ONS comparators, Bournemouth, Christchurch and Poole was the lowest at 6.5% and Coventry has the highest percentage of 28.9%.

In Southampton’s wards for the period 2018 to 2021, (3 year pooled) for those aged 85 and over the largest areas are Peartree (45.9%) and Bassett (44.1%). This is compared to 12.4% in Southampton, Freemantle has the lowest ratio of -17.1%, a negative number meaning that there are more deaths during the summer months.

In the 85 and over age group sub-city deprivation, national quintiles, between 2018 to 2021 (3 years pooled), excess winter deaths were highest in the 4th quintile (27.4%) and the 3rd quintile (17.0%). The 20% most deprived areas in Southampton, excess winter deaths were 6.6%. In the 20% least deprived areas the rate was -1.7% meaning that there were fewer deaths in the winter than in the summer.