# Introduction

The aim of this site is to give comprehensible information about trends for cause-specific mortality in different population. Charts may be viewed or downloaded after choice of population, age group and cause of death group. The measures shown in the charts have been calculated using open data from WHO (2017), but the WHO are not responsible for any content on the site. For some countries where population is not available from WHO (2017) for recent years, estimates from United Nations Department of Economic and Social Affairs, Population Division (2015) is used instead.

There are several other websites with visualizations of mortality trends. One of the most advanced is IHME (2015), which contains data for all countries in the world, and uses complicated algorithms to adjust for uncertainties in the underlying data. On this website, the charts are generated dynamically, and the sites may sometimes be slow. Moreover, the visualizations do not go further back in time than 1980, while WHO (2017) has data available from 1950, for several populations. Whitlock (2012) is a website with a great number of static charts based on WHO (2017). This website is no longer maintained, however, because its creator has died.

This website can be used for fast and easy rendering of visualizations mortality trends from the 1950s until recent years. The site contains no server-side code with any database connections. The scripts and data files used to generate the charts and the site are available via a GitHub repo.

# Measures of mortality

Mortality rate is a fundamental measure of mortality. For a cause of death $$c$$, a population $$x$$ during a time $$t$$, the mortality rate due to $$c$$ in $$x$$ during $$t$$, $$m_{c,t}(x)$$, is calculated as $$m_{c,t}(x)=n_{c,t}(x)/p_t(x)$$, where $$n_{c,t}$$ is the number of deaths due to $$c$$ during $$t$$, and $$p_t$$ is the mean population during $$t$$. If $$x$$ is a broad age interval, mortality rates for many causes will often be influenced by trends in the age distribution. If the mean age in a population increases, this will often increase mortality rates from age-related causes such as cancer, circulatory disease and dementia. WHO (2017) has data over population and number of deaths in 5-year intervals; using these, it is possible to calculate mortality rates which are not sensitive to such trends WHO (2017) has data over population and number of deaths in 5-year intervals; using these, it is possible to calculate mortality rates which are not very sensitive to such trends, and therefore gives a better measure of direct effects of things as healthcare and environmental factors on mortality. However, mortality rates in narrow age intervals, may be sensitive to random variations, especially in small populations. Therefore, this website shows unweighted averages of mortality rates over the 5-year intervals included in wider age intervals (15–44, 45–64, 65–74 and 75–84 years). Moreover, there are charts showing proportions of deaths for the different causes for all ages and ages below and above 85 years (this can be used to judge whether trends in the population as a whole are related to trends at the oldest ages, whose interpretation may be problematic).

Available data has a binary classification in females and males. For most causes, mortality rates differ significantly between females and males, and the ratio between sex-specific rates varies over time for many causes, such as ischemic heart disease and lung cancer. Because of this, all charts show sex-specific trends.

# Underlying causes and artificial trends

All data is about so-called underlying causes of deaths. For each death, exactly one underlying cause is registered in the official statistics of the different populations. It is defined as (a) the disease or injury which initiated the train of morbid events leading directly to death, or (b) the circumstances of the accident or violence which produced the fatal injury (WHO 2010, 31). In some cases, this concept is relatively unproblematic: for example, when a person dies of cancer, the primary tumor and not any metastases is underlying cause. In other cases, the interpretation is not as straightforward. Detailed instructions for choice of underlying cause of death has changed between different ICD versions, and practices for choice of underlying cause may differ between different populations using the same ICD version. Some examples, where the interpretation differs, which may give rise to artificial trends:

• Diabetes as underlying cause in people dying form ischemic heart disease or stroke.
• Pneumonia as underlying cause in people with prior diseases which increase the risk of pneumonia.

For ICD versions before ICD-10, causes of death are not available at detailed level, instead, condensed lists are used, such as the so-called A-lists in ICD-7 and ICD-8, and the BTL (Basic Tabulation List) in ICD-9. This often makes it hard to construct meaningful categories covering the same diseases for the different ICD versions, which is reflected, for example, the different categories of infectious diseases discussed below.

Years where the ICD list has changed in a population has been marked with red along the x-axis in the charts: 07A and 08A means ICD-7 and ICD-8 with A-list, 09B means ICD-9 with BTL, and 103 and 104 means ICD-10 with codes three or four characters long, where the four-character codes is the most detailed level. Dramatic changes in connection a list change can generally be assumed to be artificial.

# Included populations

The populations included are those with nearly continuous coverage of deaths and population in the WHO (2017) data from the 1950s until the 2000s. This means that most populations included are countries in Western Europe and Northern America, and other high-income countries, such as Australia, New Zeeland, and Japan. Some comments on specific populations:

Germany
Includes West Germany before 1990. Data for East Germany (whose population before the countries were merged was about one fourth of the West German population) and West Berlin are not available for the whole period, so artifical trends could not have been avoided, lest the populations had been separated.
Israel
Only data on Jewish populaton before 1975.

# Included causes of death

## All causes

All causes
ICD-6/7/8/9: 000–E999, ICD-10: A–Y Includes all causes

## Infections

Gastrointestinal infections
ICD-6/7: 040–043, 045–048, 571, 572; ICD-8: 000–003, 004, 006, 008, 009; ICD-9: 001–009; ICD-10: A00–A09 Includes different infections of the gastrointestinal tract. The cateogry is subject to artifical trends because these conditions sometimes have been included under some categories in the chapter for disease of the digestive organs (and it is not possible to separate them from other digestive diseases with only the condensed lists).
General bacterial infections
ICD-6/7: 044, 050–053, 055–058, 060–062, 340, 600; ICD-8: 005, 007, 020–039, 320, 590; ICD-9: 020–041, 320–322, 590; ICD-10: A20–A49, G00, G03, N10–N12 Includes sepsis and other bacterial infections in the first chapter in the ICD classifications, which are not included in other infectious categories, meningits, and kidney infections.
Other infections
ICD-6/7: 036–039, 049, 054, 059, 063–138; ICD-8: 040–089, 099–136; ICD-9: 045–088, 100–139; ICD-10: A65–B19, B25–B99 Includes infections in the first chapter in the ICD classifctions, except for those included in oteher infectious categories, such as different viral, parasitic and fungal infections, as well as unspecified infections. Sudden increases and decreases among, above all, younger males in some populations during the 1980s and 1990s are due to codes from this category being used for HIV infection during some periods.
Respiratory infections
ICD-6/7: 470–500; ICD-8: 460–486; ICD-9: 460–466, 480–487; ICD-10: J00–J22 Includes influenza, pneumonia and other respiratory infections (not tuberculosis). Often influenced by artificial trends when it comes to reporting these conditions as underlying causes of deaths.
Sexually transmitted diseases/HIV
ICD-6/7: 020–035; ICD-8: 090–098; ICD-9: 090–099, 279.5, 279.6; ICD-10: A50–A64, B20–B24 Includes syphilis and other predominantly sexually transmitted infections and HIV/AIDS (from ICD-9).
Tuberculosis
ICD-6/7: 001–019; ICD-8: 010–019; ICD-9: 010–018; ICD-10: A15–A19 Includes pulmonary tuberculosis, as well as other forms.

## Neoplasms

Neoplasms
ICD-6/7/8/9: 140–239; ICD-10: C00–D48 Includes malignant as well as benign and unspecified neoplasms.
Breast cancer
ICD-6/7: 170; ICD-8/9: 174; ICD-10: C50 Includes breast cancer.
Cervical cancer
ICD-6/7: 171; ICD-8/9: 180; ICD-10: C53 Includes cervical cancer.
Intestinal cancer
ICD-6/7/8/9: 152–154; ICD-10: C17–C21 Includes cancer of the small intestine, and colorectal cancer.
Leukaemia
ICD-6/7: 204; ICD-8: 204–207; ICD-9: 204–208; ICD-10: C91–C95 Includes acute and chronic leukaemia.
Lung cancer
ICD-6/7: 162–163; ICD-8/9: 162; ICD-10: C33–C34 Includes cancer in the lungs, bronchi and trachea.
Lymphoma/myeloma
ICD-6/7: 200–203, 205; ICD-8: 200–203, 208, 209; ICD-9: 200–203; ICD-10: C81–C90, C96 Includes lymphoma (Hodgkin and non-Hodgkin), myeloma and other malignancies of lymphoid or haematopoietic tissue, except for leukaemia.
Ovarian cancer
ICD-6/7: 175; ICD-8/9: 183; ICD-10: C56 Includes ovarian cancer.
Pancreatic cancer
ICD-6/7/8/9: 157; ICD-10: C25 Includes pancreatic cancer.
Prostate cancer
ICD-6/7: 177; ICD-8/9: 185; ICD-10: C61 Ages below 45 are excluded because the cases are too few.
Stomach cancer
ICD-6/78/9: 151; ICD-10: C16 Includes stomach cancer.
Tumors of the nervous system
ICD-6/7: 193; ICD-8: 191–192, 225, 238; ICD-9: 191–192, 225, 237; ICD-10: C70–C72, D32–D33, D42–D43 (for list 101 only C70–C72) Includes tumors in the brain and other parts of the nervous system.
Uterine non-cervical cancer
ICD-6/7: 172–174; ICD-8/9: 181–182; ICD-10: C54–C55, C58 Includes cancer of corpus uteri, placenta and unspecified part of uterus (which may include some cases of cervical cancer).

## Circulatory diseases

Circulatory diseases
ICD-6/7: 330–334, 400–468; ICD-8/9: 390–459; ICD-10: F01, I00–I99 Includes heart diseases, stroke (which, for ICD-10, includes vascular dementia), and other circulatory conditions. Cardiovascular disease may be used as a synonymous expression, but may also refer to subclasses of this disease category.
Arterial disease except for IHD and stroke
ICD-6/7: 450–456; ICD-8/9: 440–448; ICD-10: I70–I79 Includes arterial diseases not included in ischemic heart disease and storke (arteriosclerosis outside the brain or heart, or with general or unspecified location, aortic aneurysm). Excludes hypertensive disease.
Heart disease
ICD-6/7: 400–447; ICD-8/9: 390–429; ICD-10: I00–I51 Includes conditons related to the heart, such as ischemic heart disease, hypertension, diseases of the pulmonary circulation, myocarditis, valvular heart disease and functional heart conditons (such as heart failure).
Ischemic heart disease
ICD-6/7: 420–422; ICD-8/9: 410–414; ICD-10: I20–I25 Includes myocardial infarction and other conditions due to insufficient oxygen supply to the heart muscle. Coronary heart disease is often used as a more or less synonymous expression. The conditions is commonly abbreviated as IHD. This category is not defined in classifications before ICD-8: the nearest category in ICD-6/7 available from the condensed WHO lists is arteriosclerotic and degenerative heart diseases. For some populations, such as Italy and Japan, this leads to significant artificial trends wit the switch to ICD-8.
Non-IHD circulatory diseases
Includes all codes in the circulatory disease category, except for those included in ischemic heart disease. This category is included because of the importance of ischemic heart disease in determining secular trends for circulatory diseases in many populations.
Non-atherosclerotic circulatory diseases
Includes all codes in the circulatory disease category, except for those included in ischemic heart disease, stroke and other arterial disease. Mainly conditions in the general category for heart disease except for ischemic heart diseases. This category is included because of the importance of ischemic heart disease and other conditions typically ascribed to atherosclerosis in determining secular trends for circulatory diseases in many populations.
Stroke
ICD-6/7: 330–334; ICD-8/9: 430–438; ICD-10: F01, I60–I69 Includes cerebral haemorrhage, cerebral infarction and other cerebrovascular diseases. For ICD-10 with detailed list, vascular dementia is also included.
Stroke and atrial fibrillation
ICD-6/7: 330–334; ICD-8/9: 430–438; ICD-10: F01, I48, I60–I69 Includes cerebral haemorrhage, cerebral infarction and other cerebrovascular diseases. For ICD-10 with detailed list, vascular dementia and atrial fibrillation (in recent years often reported as underlying cause of cerebral infarction) are also included.

## Other diseases

Chronic respiratory diseases
ICD-6/7: 501–527; ICD-8/9: 490–519; ICD-10: J30–J98 Includes COPD, asthma, and other non-infectious, non-neoplastic respiratory diseases.
Dementia/neurodegenerative disease
ICD-6/7: 300–309, 341–352, 354–369, 380–384, 386, 388–390, 394–398; ICD-8: 290–299, 321–344, 346–358, 370–373, 376–380, 384–389; ICD-9: 290, 330–340; ICD-10: F01–F09, G10–G37 (för lista 101 F01–F99, G04–G98) Includes neurodegnerative diseases (like Alzheimer, Parkinson, mutliple sclerosis), including so-called organic mental disorders (mostly dementia) in the chapter for mental disorders. Increases in the proprtion of deaths among old people during later decades are mainly due to a tendency to more often report dementia rather than e.g. pneumonia or atherosclerosis as underlying cause of death (compare the estimations of trends in dementia mortality from the 1980s based on prevalence, available from IHME (2015)).
Dementia/neurodegenerative disease, non-VD
Identical with the category for dementia and neurodegnerative diseases, except that it excludes F01, vascular dementia, for ICD-10 with detailed list. This category has been includes to have a defintion of dementia and neurodegnerative diseases disjoint with stroke for ICD-10.
Diabetes
ICD-6/7: 260; ICD-8/9: 250; ICD-10: E10–E14 Diabetes mellitus (type 1 and type 2). The tendency to report diabetes rather than compliacations (such as ischemic heart disease) as underlying cause of death often varies between populations and over time within populations.

## Ill-defined causes

Ill-defined causes
ICD-6/7/8/9: 780–799; ICD-10: R00–R99 Includes codes in the second last chapter in the ICD classifications, such as deaths without any mentioned cause at all, symptom without mentioned causes, and senility (old age without mention of dementia). A high proportion of deaths in this category may indicate poor quality of the reporting, and implies that trends for other causes have to interpreted with caution. Some codes in other ICD chapters may also be regarded ill-defined when reported as underlying causes of death (such as heart failure and respiratory failure without mentioned cause). Some formally well-defined causes may in some populations be overreported so that their diagnostic meaning is watered down (such as ischemic heart disease among older people).

## External causes

External causes
ICD-6/7: E800–E999; ICD-10: V01–Y89 Includes accidents, suicides, homicides, legal interventions and even complications of medical care (in these cases, the diseases behind the medical interventions are often reported as underlying causes of death, however).
Accidental falls
ICD-6/7: E900–E904; ICD-8: E880–E887; ICD-9: E880–E888; ICD-10: W00–W19 Trends may be infleunced by tendency to report unspecified accidents or complications of falls (such as thrombosis or pneumonia) as underlying causes.
Suicide
ICD-6/7: E963, E970–E979; ICD-8/9: E950–E959; ICD-10: X60–X84 Includes also cases with underlying mental disorder, such as depression. Does not include events of undetermined intent. Trends may be influenced by propensity of reporting suicide.
Transport accidents
ICD-6/7: E800–E866; ICD-8: E800–E845; ICD-9: E800–E848; ICD-10: V01–V99 Includes accidents with motor vehicles and other kinds of transprot accidents.

## References

IHME. 2015. ”COD Visualization”. https://vizhub.healthdata.org/cod.

United Nations Department of Economic and Social Affairs, Population Division. 2015. ”World Population Prospects”. https://esa.un.org/unpd/wpp/.

Whitlock, Gary. 2012. ”Mortality Trends [arkiverad 21 december 2014]”. http://web.archive.org/web/20141221203103/http://www.mortality-trends.org/.

WHO. 2010. ICD-10 volume 2 Instruction Manual 2010 Edition. http://www.who.int/classifications/icd/icdonlineversions/en/.

———. 2017. ”WHO Mortality Database”. http://www.who.int/healthinfo/mortality_data/en/index.html.