Exam #2 Flashcards
Numbers alive in 2000 US population (000) who would have suffered various fates if 1900 mortality conditions prevailed (White and Preston 1996)?
Hypothetical Total Deaths 137,277 50% of actual pop. Been born and died (direct deaths) 68,441 25% of actual pop. Had mothers who died before their birth 38,096 14% of actual pop. Had grandmothers who died before mother’s birth 22,573 8% of actual pop. Had earlier ancestor die 8,167 3% of actual pop.
Selected life expectancy figures:
Pre-history (before 1300) 20-25 years Greeks, Romans 20-30 British aristocrats 1330 – 1650 30 England 1600-1750 35 1800-1850 39 1900 47 1990 75 2010 80.1 U.S. 1900 48 2010 78.7
Life expectancy at birth, 2011:
Range: Sierra Leone 47 to Japan 83
Global average: 70 years
Points of Reference:
U.S. (78.7), Canada (82), Mexico (75)
Classification of Causes of Death (WHO):
- Infectious and parasitic diseases
- Degenerative or chronic diseases
- Products of the social and economic environment
- Reductions in death rates from infectious and parasitic diseases led to dramatic mortality decline.
- Historically, mortality improvements occurred among young. Today, improvements are concentrated among old.
Hunter-gatherer societies:
Life expectancy = low 20s
Golden Age of Bacteria (1300-1650):
Exchange of diseases among populations newly in contact
- Smallpox
- Syphilis
The Plague
1650 - 1850:
Population growth begins as mortality rates start to decline slowly
Factors responsible for mortality decline (Europe):
- Disappearance of plague
- Agricultural revolution
Medical technology
- Smallpox vaccination developed purely by observation
- No theory of disease was developed at this time
What accounts for mortality decline after 1850?
Economic growth leading to improved nutrition and increased standards of living
Medicine
Public and private preventive measures
These explanations are not mutually exclusive and their relative importance has been of much contention.
Mortality decline due to economic growthThomas McKeown: Modern Rise in Population (1976):
For multiple diseases, bulk of mortality decline occurred BEFORE effective drugs became available .
Concluded that economic growth (which led to improved nutrition) must be responsible but provided no direct proof.
Mortality decline due to economic growth (Robert Fogel):
Found a close connection between improved nutritional status (e.g. height) and lower mortality
Miasma Theory:
A representation of the cholera epidemic of the 19th century depicts the spread of the disease in the form of poisonous air.
Public and Private Preventive Measures:
Germ theory of disease replaces miasma theory (1870s) and led to a series of public and private health initiatives
Public Health Initiatives
- Water sewer systems and sewage disposal improvements
- Pasteurization of milk
Private Health Initiatives:
Better Mothering Campaigns
- “We’ve discovered that the source of most diseases is not outside the home in public spaces, but inside the home. You’re making one another sick. Mothers, it’s your responsibility to maintain hygienic conditions and save your babies. Here’s what you can do.”
Formation of Children’s Bureau (1912)
Main Points:
Dramatic improvements in life expectancy over time since 1850s
Through transition, major causes of death change from infectious to noninfectious, chronic diseases
MDRs have completed the mortality transition
Much of MDR decrease in mortality occurred BEFORE modern medical advances, so medicine is NOT seen as a primary explanation for the decline.
Although debate continues, most demographic and medical historians conclude that mortality declined largely because of public and private health interventions. Rising standards of living as part of economic growth also played a role.
Epidemiological TransitionOmran, 1971:
Basic Components
High and fluctuating mortality and low life expectancy caused by infectious disease replaced by low, stable mortality and high life expectancy
Degenerative and manmade diseases become major causes of death
A shift in mortality from young to old ages.
Increase in life expectancy is implicit in these changes.
Three possible models:
- The Classical or Western Model
Gradual transition due to combination of economic growth, public health, medicine - The Accelerated Model
More rapid transition due largely to public health and medical measures as well as social improvements - The Contemporary Delayed Model
Recent, yet to be completed transitions in LDRs
Public health and medical measures play key role
Key factors in producing mortality decline in LDRs:
Public health initiatives
- Most important is the eradiation of disease-carrying insects/rodents (e.g. DDT and malaria)
- Water sewage improvements
Routes to Low Mortality in LDRs Three countries were particularly successful in lowering mortality rates quickly: Kerala, India; Sri Lanka; Costa Rica
- Important cultural factors
Female autonomy, emphasis on education, egalitarian - Health services
Relied on immunization campaigns, nutritional floors, household visits rather than expensive technology - Created important symbiosis between health services and culture - importance of women’s schooling
Routes to Low Mortality in LDRs
Alternative routes to mortality:
- China; Cuba; Vietnam
- Devoted large resources to health sector. Achieved lower mortality through sheer political will.
Update (Kuhn, 2010)
- Success in Latin America – role of cost-effective primary care programs, increasing democratic inclusion, conflict resolution
- Recent reductions in Muslim world (e.g. Bangladesh) – targeted investments in health systems, narrowing of male/female schooling gap, reliance on human capital rather than resources
The importance of women:
- Women’s education is a strong predictor of child mortality.
- Strong effect on infant mortality rates.
Remaining problems in LDRs:
- Increase in death rate from chronic diseases
- Infant mortality
- Sex differentials in mortality
Remaining Challenges in High IMR countries:
Effectively implementing preventive measures
- Diarrhea; immunization; respiratory infections; malaria; perinatal causes
Need to focus resources on preventive care rather than curative medicine
Why the excess female child mortality?
No biological cause
Rather, excess mortality results from a pattern of relative neglect of female children in some countries
- Less nutrition and medical care for girls
- Deep cultural underpinnings
Cohort life table?
Follows a group of individuals (cohort) from birth to death to record their actual mortality experiences. Useful for many epidemiological/medical applications, but less useful for demographers
Period life table?
Life table based on a hypothetical (“synthetic”) cohort, using age-specific mortality rates from a given year
Short period advances in life expectancy?
World life expectancy has more than doubled in the past 200 years.
- From about 25 years to 65 years for men
- From about 25 years to 70 years for women
Senescence? Its two modern biological theories?
physical condition of the body declines and person becomes more susceptible to disease.
- Programmed theories – we age by design
- Damage or error theories – we age because we experience wear and tear on our bodies
Planned Obsolescence or Gene Expression Theory of Aging?
- Aging follows a biological timetable
- The number of repeats in a telomere determines maximum life span of a cell
- May explain why we see variation in life expectancy across species
Damage/Error Theories or Stochastic Theory of Aging?
- Humans wear out due to stresses and strains of constant use
- Emphasizes environmental factors that may accelerate the aging process
- Helps us to understand why we may see variation in life expectancy within a species
Two views on life expectancy?
Limited: A glass ceiling on life expectancy (Olshansky)
Unlimited: No inherent limits to life expectancy (Vaupel)
How to extend the human lifespan?
Develop better treatments and medication for major killers. (We die because we get sick)
- Cancer cures
- Replace damaged body parts with stem cell therapies.
Slow down the aging process at the molecular and cellular levels. (We die because we get old)
