Global patterns of health and disease

What 3 things is health linked to?

Physical environment e.g. air and water quality.

Social environment e.g. educational opportunities, medical access

Economic environment e.g. type of housing, jobs, etc.

Define health

Defined by WHO as a state of complete physical, mental and social well-being and not merely the absence of disease.

Define morbidity

Relates to illness and disease. Used to describe the incidence of a disease within society. Indicated by its prevalence in society (number of cases at a particular time) and incidence (number of new cases during a particular time period).

Define mortality

Relates to death.

How is health, mortality and morbidity measured by?

Health measured by HALE and DALYs.

Mortality measured by DR, infant mortality etc.

Morbidity measured by total number of cases of a disease in a society or number of new cases.

Outline the global patterns of health

Using HALE: highest for HICs, particularly in HICs of East Asia e.g. life expectancy 83 Japan. High in European countries. Lowest in LICs particularly in Northern and Sub-Saharan African countries e.g. CAR (54.4). Low in isolated areas due to conditions e.g. Haiti (hazards) and Afghanistan (war). Trend of increasing income → increasing life expectancy.

Outline the global patterns of morbidity

Depends upon disease type; communicable disease most prevalent in LICs and tropical regions where disease can spread quicker e.g. TB→ highest morbidity in regions of sub-Sahara Africa (+300 cases per 100,000 in 2015), India and SE Asia. Lowest across Western Europe, Australia and US.

Non-communicable diseases highest in HICs e.g. Western Europe, Australia, US and more recently NEEs.

Globally NCDs each year are responsible for around 74% of deaths globally (increasing proportion as infectious diseases decline).

Outline the global patterns of mortality (spatial and age)

Spatial: Mortality risk greatest for young women in poorer regions due to childbirth complications. Risk of death from disease much higher in less developed regions. Mortality rates differ in a country each year e.g. due to epidemics, natural hazards etc.

Age: highest in over 70s, lowest in children under 15 however varies by country e.g. in areas where malaria is prevalent infant mortality is higher.

Give an example to show that mortality does not = morbidity

Globally, the lowest risks of NCD mortality in 2016 were seen in high-income countries in Asia-Pacific, western Europe, and Australasia, and in Canada. The highest risks of dying from NCDs were observed in low-income and middle-income countries, especially in sub-Saharan Africa, and, for men, in central Asia and eastern Europe. This is opposite to morbidity as highest incidence of NCDs in HICs.

What are the reasons for mortality, morbidity and health variations globally?

Health- depends upon how much disease is in the country (env + social factors), and types of diseases (CD vs NCD), as well as factors such as well-being.

Morbidity- CD is LEDCs due to lack of sanitation and health care, limited health education and overcrowding of urban areas. NCD is MEDCs due to: elderly population that are more likely to suffer from NCDs; unhealthy lifestyles more common in developed countries.

Mortality- higher in LEDCs due to malnutrition and poor access to health care.

What are DALYs?

Disability adjusted life years: a measure of morbidity within a society by measuring the number of years of healthy life lost by being in poor health or state of disability. Developed countries tend to have lower DALYs indicating they are closer to ideal health.

What is the difference between communicable and non-communicable disease?

Non-communicable: medical conditions/disease that aren’t infectious.

Communicable: conditions passed from one person to another.

What is the general trend between health and socio-economic development?

As societies develop, socio-economic conditions should improve. Improvements in food supply and improved infrastructure should lead to less famine and malnutrition related disease. Improving hygiene and clean water reduces spread of water-borne diseases. Vaccination programmes can eradicate infectious disease.

List economic developments that are linked to improved health.

Technology→ improve food productivity and supply (green revolution).

Transport + infrastructure→ distribution of food and medical supplies.

Investment in drainage and sewage systems.

Trading of resources and goods in exchange for wider food variety and medicines.

List social developments that are linked to improved health.

Sanitation

Better education of disease transmission and hygiene.

Advances in medical technology e.g. vaccines

Better training of medical professionals

Aid programmes, NGO provision to improve healthcare resources.

What is the epidemiological transition?

Proposed in 1971 by epidemiologist Abdel Omran: Describes how mortality rates change over time as counties develop. Assumes that infectious diseases are replaced by chronic diseases over time as a country undergoes modernisation (developing to developed status). Stages can be linked to DTM

What are the 4 stages of the epidemiological transition?

1. Age of pestilence and famine: high mortality and fluctuates preventing sustained pop growth. Low life expectancy. Association to wars, epidemics, etc.

2. Age of receding pandemics: mortality rate declines as epidemics are less frequent and pop growth exponentially increases as life expectancy increases. Associated with medical advances and development of healthcare systems.

3. Age of degenerative and man-made disease: mortality continues to decrease and stabilise at low level. Infectious disease replaces with non-communicable degenerative. Fertility high and important to pop growth.

4. (Added later in 1980s) Age of delayed degenerative diseases: Life expectancy rises to late 70s and early 80s. Mortality delayed until older ages due to treatments and prevention of man-made and degenerative diseases

What is the 5th stage people argue for epidemiological transition?

Re-emergence of infectious disease due to antibiotic resistant bacteria as well as increasing travel and trade→ spread of disease.

What do the WHO predict for future in disease?

Next two decades to see increase in lifestyle and behaviour related diseases to account for 70% of all death in developing regions. Suggests that public health policies will need to adapt to changes from emphasis on infectious diseases.