Causes of premature death

1. Key messages

2. Causes of death - Belgium

Tumour is the main group of causes of premature deaths

The main groups of causes of premature deaths are tumours, diseases of the circulatory system, and external causes (mostly suicides and road accidents).

The proportion of tumours in premature deaths is higher in women than in men. Conversely, the proportions of diseases of the circulatory system and external causes are higher among men. In 2021, the proportion of deaths due to COVID-19 was higher in men than in women, and the opposite was observed for diseases of the respiratory system. 

Lung cancer and COVID-19 are the main causes of premature deaths in Belgium

Based on age-adjusted premature mortality rates, lung cancer and COVID-19 were the leading causes of death in 2021 for both men and women. In third place for men was ischemic heart disease and for women breast cancer. 

When expressed in the number of potential years of life lost (PYLL), a measure that takes age at death into account, then the ranking is different. In men, suicide then becomes the leading cause of death, followed by COVID-19 and lung cancer. Among women, breast cancer takes first place, followed by lung cancer and suicide. Transport accidents also appear in sixth place among men.

Positive trends for the main causes of premature death, but some points of attention remain for women

Most causes of premature deaths tend to decrease (or at least remain stable) over time, but there are some exceptions.

• Premature mortality due to ischemic heart disease fell by 31% in men and 37% in women over the period 2011-2021 ;
• The same trend is observed for cerebrovascular diseases, with a 23% reduction in men and 16% in women;
• Premature lung cancer mortality rates have also fallen considerably in men (38% reduction between 2011 and 2021);
• In contrast, premature lung cancer mortality rose dramatically among women (60% increase) between 2000 and 2015, then stabilized. From the fourth leading cause of death in 2000, it has risen to first place, just above breast cancer;
• An increase in COPD in women was observed in the years preceding COVID-19 (28% increase between 2011 and 2021).

3. Causes of death - Regions

COVID-19, lung cancer, breast cancer, and suicide are the main causes of death in the three regions

In 2021, according to the age-adjusted premature mortality rate:

• Among men, the leading causes were COVID-19, which ranks first in the Walloon and Brussels-Capital Regions and second in the Flemish Region; lung cancer, which ranks first in the Flemish Region and second in the other regions; and ischemic heart disease in the third place. 
• Among women, the leading causes were lung cancer, which ranked first in the Flemish and Walloon Regions and second in the Brussels-Capital Region, COVID-19, which ranked first in the Brussels-Capital Region, and breast cancer. 

In 2021, according to the potential years of life lost (PYLL):

• Among men, the leading causes were suicide, which ranks first in the Flemish and Walloon Regions and third in the Brussels-Capital Region, lung cancer and COVID-19, which ranks first in the Brussels-Capital Region.
• Among women, the leading causes were breast cancer, which ranks first in the Flemish Region and second in the Walloon and Brussels-Capital Regions, and lung cancer, which ranks first in the Walloon Region and third in the other regions. In 2021, COVID-19 was the primary cause of death in the Brussels Capital Region, whereas it ranked fourth in the other regions.

Mortality rates are generally higher in the Walloon Region than in the other regions, except for COVID-19 in the Brussels-Capital Region.

COVID-19 is the main cause of death, leading to regional differences 

As shown on the page ‘Premature mortality’, there are major regional disparities in the age-adjusted premature mortality rate. Here we analyze which causes of death contribute most to the regional difference in age-adjusted mortality rates, by subtracting the cause-specific mortality rates of the Flemish Region from those of the other regions and ranking the differences.

Among men, the causes of death contributing most to the excess premature mortality in the Walloon Region compared to the Flemish Region are COVID-19 (+34 per 100,000), ischemic heart disease (+17), lung cancer (+11), chronic liver disease (+7.7) and COPD (+7.6).

Among women, the causes of death contributing most to the excess premature mortality in the Walloon Region compared to the Flemish Region are COVID-19 (+15 per 100,000), COPD (+7.9), ischemic heart disease (+5), lung cancer (+4.7) and infectious and parasitic diseases (+4.5). As rates are lower for women than for men, regional differences by cause among women are smaller.

Among men, the causes of death contributing most to the excess premature mortality in the Brussels-Capital Region compared to the Flemish Region are COVID-19 (+54 per 100,000), ischemic heart disease (+7.9), lung cancer (+5.4), COPD (+5.2) and diabetes (+4.7). However, lower rates are found for some specific causes in the Brussels-Capital Region than in the Flemish Region, such as suicide (-4.5) and transport accidents (-3.4).

Among women, mortality rates by cause in the Flemish Region and the Brussels-Capital Region are generally relatively similar. However, in 2021, as in 2020, we observed a higher premature mortality in the Brussels-Capital Region for COVID-19 (+21 per 100,000) than in the Flemish Region.

Most causes of premature deaths decline among men

Trends in premature mortality by cause of death are fairly similar for all three regions. Here we highlight five interesting trends for specific causes of death. In addition, you can find information on trends in suicide mortality on the suicidal behaviour page.

1. The premature mortality rate from lung cancer has decreased among men in all three regions over the period 2011-2021 (-34% in the Walloon Region, -41% in the Flemish Region and -31% in the Brussels-Capital Region). These rates have remained higher in the Walloon Region than in the Flemish Region over the whole period.

Among women, the premature mortality rate from lung cancer increased in the Flemish and Walloon Regions until 2015 and 2013 respectively, while remaining stable in the Brussels-Capital Region since 2007. Women in Brussels used to have the highest rates of premature lung cancer mortality, but, since 2010, women in the Walloon Region experience the highest rates. A slow decline in mortality has been observed in recent years; between 2011 and 2021, the decrease is significantly greater in the Brussels-Capital Region (-31%) than in the Flemish Region (-12%) and the Walloon Region (-12%).

2. Premature mortality rates due to ischemic heart disease are decreasing more rapidly among women (-31% in the Walloon Region, -38% in the Flemish Region and -61% in the Brussels-Capital Region) than among men (-26% in the Walloon Region, -35% in the Flemish Region and -34% in the Brussels-Capital Region). The decreasing trend is slowing down for men in recent years. Among men, rates in the Walloon Region have consistently been higher than in the Flemish Region, and this gap is widening, with a faster decline in the Flemish Region than in the Walloon Region. 

3. The premature mortality rate from breast cancer in women has decreased in all three regions over the period 2011-2021 (-35% in the Flemish Region, -32% in the Walloon Region and -44% in the Brussels-Capital Region). Regional differences in breast cancer are small.

The premature mortality rate from breast cancer is very low among men and therefore not presented here.

4. Among men, premature COPD mortality rates decreased in all three regions between 2011 and 2021; the decrease was 33% in the Walloon Region, 26% in the Flemish Region and 27% in the Brussels-Capital Region. The rate is the highest in the Walloon Region, but regional differences diminish over time. In contrast, mortality rates for women increased between 2011 and 2021 in the Walloon Region (+14%) and in the Flemish Region (+12%). The decrease in mortality in the Brussels-Capital Region was 14%. COPD mortality in women was lower in 2020 but increased again in 2021.

5. There is a strong decrease in the premature mortality rate due to colorectal cancer between 2011 and 2021. This decrease is greater in the Flemish Region (-36% in men, -38% in women) than in the Walloon Region (-19% in men, -9% in women) and the Brussels-Capital Region (-25% in men, -19% in women). As a result, the Flemish Region has gone from being the region with the highest premature mortality rates for colorectal cancer in 2000 to the region with the lowest mortality rates for this disease in 2021.

4. Read more

View the metadata for this indicator

Statbel: Causes of death

Sciensano: Standardized Procedures for Mortality Analysis (SPMA)

WHO: ICD-10

Background

The causes of death are classified according to the International Classification of Diseases 10th Revision (ICD-10) [1]. In this report, mortality is analyzed with the underlying cause of death as indicated on the death certificate. The underlying cause of death is by rule preferred to the immediate and the contributing causes of death for mortality statistics because, from a public health perspective, the objective is to break the chain of events leading to death and to prevent the precipitating cause [1].

In a first step, the causes of premature death are presented here according to the ICD-10 main chapters. Those are based on the first digit of the ICD-10 code. In a second step, the 10 most important specific causes of premature death are ranked by mortality rates for Belgium and by regions.

Premature mortality refers to deaths occurring at any age lower than the life expectancy. In the operational definition used here, the threshold was set to the mortality occurring below 75 years of age. Most of the causes of premature death are avoidable either through the health care system or by the implementation of public health policies. Reducing premature mortality is a key public health objective. The ranking of the causes of premature deaths is as a consequence a very important tool to set up public health priorities.

The premature mortality by cause can be evaluated either by using:

• Premature mortality rates, which measure the frequency of deaths due to a specific condition occurring before 75 by 100.000 people under 75 in the population. This indicator is allowing to compare the frequency of different causes of death.
• Potential Years of Life Lost (PYLL), which is taking into account the frequency and the age at death, is weighting each death in function of the age when the death occurred and is thus gives more weight to death occurring at younger ages. PYLL’s consequently allow to compare causes according to their burden in terms of years of life lost [2].

The importance of the causes of premature deaths can be expressed in rates which reflect only the frequency of the cause or in PYLL which reflects the burden of the cause in terms of years of life lost. The PYLL-based ranking ranks external causes higher than the rates-based one because external causes usually occur at a younger age than deaths due to chronic diseases.

Both indicators are adjusted for age using the structure of the European standard population 2010 as reference in order to take into account the effect of variations in the age structures between populations.

The COVID-19 mortality between 2020 and 2022 based on the ad-hoc surveillance is analyzed in a factsheet.

Definitions

Crude mortality rate

The crude mortality rate is the number of deaths registered in a population divided by the number of people in this population.

Age-standardized (or age-adjusted) mortality rate

The age-standardization is a weighted average of age-specific mortality rates to remove variations arising from differences in age structure between population groups.

International Classification of Diseases (ICD-10)

The International Classification of Diseases is an international codification for diseases and for a very wide variety of signs, symptoms, traumatic injuries, poisonings, social circumstances and external causes of injury or illness.

Potential Years of Life Lost (PYLL)

The potential years of life lost (PYLL) measure the number of years of life that have been lost due to premature death. The PYLL weights the deaths occurring in younger age groups more heavily than the ones occurring in older people. The calculation of PYLL involves summing up deaths occurring at each age and multiplying this with the number of remaining years to live up to a selected age limit (here, 75 years). Age-specific PYLL rates are calculated by dividing the number of PYLL in a given age group by the number of people in this age group. An age-adjusted PYLL rate is then calculated as a weighted average of age-specific PYLL rates until 75 years.

Premature mortality rate

The premature mortality is defined here as deaths occurring before the age of 75; the age-standardized premature mortality rate is calculated as a weighted average of age-specific mortality rates until 75 years.

Underlying cause of death

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.

Tumours

Also known as neoplasms in ICD-10. The neoplasms group includes 95% of malignant neoplasms (or cancers), the other 5% being tumours of benign or borderline behaviour.

References

1. World Health Organization. International statistical classification of diseases and related health problems 10th. 2016.
2. Gardner JW, Sanborn JS. Years of Potential Life Lost (YPLL). What Does it Measure? Epidemiol 1990;1:322-9.

Please cite this page as: Sciensano. Mortality and Causes of Death: Causes of premature death, Health Status Report, 15 Apr 2024, Brussels, Belgium, https://www.healthybelgium.be/en/health-status/mortality-and-causes-of-death/causes-of-premature-death