Chapter 7

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