Determinants of Population Health

• Population health perspective: recognizes complex interactions of individual and societal factors in determining health

• Determinants are interconnected and operate in interaction with each other

• Socioeconomic status: is a major determinant of conditions that impact the well-being

  • Link with the risk of vascular and chronic diseases

• Emphasis on the reduction of socioeconomic inequalities and poverty

• Better health = more productive workforce

• Societal affluence = good health

• Gender: encompasses biological and sociological dimensions linked to variations in health, morbidity, and mortality risks

• Culture can also be an important influence

Demographic and Sociological Dimensions of Mortality

• Mortality: the number of deaths taking place in a given interval in a specific population

• Long-term decline of the death rate

Basic Measures of Mortality

Crude Death Rate

• CDR: number of deaths in a given interval (year) divided by the midpoint population

• Three-year average CDR

• Highest CDR: Sierra Leone + Zambia + Afghanistan

• Some developing countries have lower CDR because their age compositions are younger than those in developed countries

Age-Specific Death Rate

• ASDR: number of deaths in a given interval to persons of a given age divided by the mid-interval population at risk in that same age category

Age Pattern of Mortality

• J-shaped pattern of mortality: common in more developed countries

• Mortality probabilities are higher for men than women

• Age pattern of mortality: the shape of the pattern of death rates over age

• Level of mortality: the overall death rate of a population

  • Lower for advanced countries than poorer nations

Infant Mortality Rate and Its Components

• Early neonatal mortality: includes deaths that occur between birth and the end of the first week of life

• Late neonatal mortality: includes deaths that occur from 8th day after birth to the end of the 27th day after birth

• Post-neonatal mortality: includes deaths from the 28th day after birth to the end of the 1st year

• Fetal deaths: death of a fetus prior to its complete removal or expulsion from the mother

• Miscarriage: spontaneous or accidental termination of fetal life early in pregnancy

• Abortion: any termination of pregnancy

• Infant mortality rate (IMR): number of infant deaths in a given year divided by the number of live births in the same year

  • IMR in Central African Republic: 116

  • IMR in Japan and Sweden: 2

• Developing countries have higher rates of infant mortality

Causes of Death in Infancy

• Endogenous infant deaths: related to genetic makeup or internal physiological processes in the fetus - stem from complication

• Exogenous infant deaths: associated with external factors

• Improvements to public health decrease the causes of post-neonatal and early childhood mortality

• Low birth weight: prematurity

Cause-Specific Death Rate

• Heart disease + cancer = important causes of mortality in industrialized countries

• Underlying cause of death: initial cause of the morbid process leading to death

• Cause-specific death rate: number of deaths due to a disease divided by the mid-interval population

• Cause-specific death ratio: the percentage of all deaths in the population that are attributable to causes of diseases

The Life Table

Basic Description of the Life Table

• Life table: describes the survival experience of a fictional cohort subjected to the current age-specific death rates of a population

Mortality Change through History

• Recent increase in life expectancy

  • Decrease in infectious and pathogenic diseases

Epidemiological Transition

• Abdel Omran

  • Before modernity: infectious/parasitic diseases + famine + war = premature deaths

  • Chronic + degenerative diseases now became the leading killers

The Age of Famine and Pestilence

• Mortality + fertility = very high

• Rural population

• Traditional society

• Economy = agrarian system

• Low standards of living

• Life expectancy at birth for women: 20-35 years

• Mortality = higher in urban areas

The Age of Receding Pandemics

• Early phase

  • Improvements in health, agriculture, transportation, communication, standards of living and industrialization

  • Slow decline in mortality

  • Mortality = higher in urban areas

  • Epidemics

  • No health care system

• Late phase

  • Explosive population growth

  • High fertility + mortality decline

  • Improvement in agriculture, sanitation, hygiene

  • Rise of the expectancy at birth

  • Vaccination

  • Increase in non-infectious diseases (heart disease + cancer)

The Age of Human-Made and Degenerative Causes of Death

• Increases in life expectancy

• Mortality decline

• Non-infectious diseases

• Urban population

• Technology + science

• Organized society

• Nuclear family

• Morbidity: rates of disease

• Health systems

• Causes

  • Smallpox vaccine

  • Standards of living thesis: recession of virulent epidemic diseases

Extensions to Epidemiological Transition Theory

The Age of Delayed Degenerative Diseases

• Decline in cardiovascular diseases

The Hybristic Stage

• Features linked to lifestyle and health behaviour: smoking, overeating, unhealthy diet, avoiding exercise

• Infection diseases (HIV)

• Chronic and communicable disease mortality

• In some poor countries, major health improvements are possible without large-scale economic growth

• Agent of health transition can be the Church

Health Transition

• Health transition: improvements in life expectancy and overall health of populations over the historical spectrum

• Systemic factors: related to the environment and social organization

• Societal factors: cultural and structural determinants (stratification/inequality)

• Institutional/household-level factors: working/living conditions, health care systems, lifestyles

• Individual factors: health status, behavioural risk factors

Inequalities in Health and Mortality

The Sex Differential in Mortality

• Increase in the sex gap: women are living longer than men

• Maleness has some intrinsic risks that are genetic/biological kin origin

• Immunocompetence: an organism’s all-around ability to avoid the harmful effects of parasites

  • Low for males

    • Testosterone

• Men have higher death rates from vascular diseases

• Behavioural components: stress, safety, diet, substance abuse

  • Greater risk taking + aggressiveness

• Manhood trials: dangerous rites of passage

• Declining sex difference in life expectancy is largely due to the faster declines for men in death rates

• More female deaths are concentrated in older ages

The Aboriginal Disadvantage in Health and Survival

• Deplorable socioeconomic and epidemiological conditions

• Life expectancy is lower than other Canadians

• Canada’s Aboriginal populations are undergoing the epidemiological transition

• More chronic and degenerative diseases

• More incidence of high birth weight babies

• Higher mortality risk

Socioeconomic Disparities in Health and Mortality

• As socioeconomic status increases, mortality declines

  • More money = access to health care

• Factors of socioeconomic inequality

  • Low social status

  • Poor social affiliations

  • Poor quality or early childhood experiences

• Psychosocial dimensions

Canadian Mortality in Comparative Perspective

• US: low infant mortality, high life expectancy, high rates of adolescent birth rates

• Japan + Sweden: low infant mortality, high life expectancy - top

• United Kingdom: high rates of adolescent birth rates

Future Prospects

• Future increase in the incidence of cancer

• Respiratory conditions

• Congenital anomalies

• Public efforts to reduce inequalities

• Greater public health interventions