Chapter Two

Health Determinants, Measurements, and Trends

The Importance of Measuring Health Status

In order to address global health issues, we must understand:

• The factors that influence health status most• The indicators used to measure health status • The key trends that have occurred historically

Determinants of Health

• The interconnected factors that determine an individual’s health status

• Determinants include personal features, social status, culture, environment, educational attainment, health behaviors, childhood development, access to care, and government policy

• Increasing attention is being paid to the “social determinants of health”

Figure 2.1: Key Determinants of Health

Key Health Indicators

Health status indicators are useful for: • Finding which diseases people suffer from• Determining the extent to which the disease

causes death or disability• Practicing disease surveillance

To perform these functions, it is important to use a consistent set of indicators

Table 2.1: Key Health Status Indicators

Source: Data from the Public Health Agency of Canada. What Determines Health. Available at: http://www.phac-aspc.gc.ca/ph-sp/determinants/ index-eng.php#determinants. Accessed November 19, 2010.

Figure 2.2: Life Expectancy at Birth, by World Bank Region, 2008

Figure 2.3: Infant Mortality Rate

Figure 2.4: Neonatal Mortality Rate

Figure 2.5: Under-5 Child Mortality Rate

Figure 2.6: Maternal Mortality Rate

Key Health Indicators

Terms• Morbidity- sickness or any departure, subjective or objective,

from a psychological or physiological state of well-being • Mortality- death• Disability- temporary or long-term reduction in a person’s

capacity to function• Prevalence- number of people suffering from a certain health

condition over a specified time period• Incidence- the rate at which new cases of a disease occur in a

population

Key Health Indicators

Classifications of Disease • Communicable disease- illnesses caused by a

particular infectious agent that spread directly or indirectly from people to people, animals to people, or people to animals

• Noncommunicable disease- illnesses not spread by an infectious agent

• Injury- include road traffic injuries, falls, self-inflicted injuries, and violence, among other things

Vital Registration

• Vital registration systems record births, deaths, and causes of death

• An accurate system is key to having quality data on a population

• Many low- and middle-income countries lack a vital registration system

• Developing a system is progress towards understanding and addressing health problems

Measuring the Burden of Disease

• Twp indicators used to compare how far countries are from a state of good health

• Health-Adjusted Life Expectancy (HALE)- summarizes expected number of years to be lived in what might be termed the equivalent of good health

• Disability-Adjusted Life Year (DALY)- a unit for measuring the amount of health lost because of a particular disease or injury

Measuring the Burden of Disease

DALY• “Health gap measure,” indicating losses due to

illness, disability and premature death in a population

• Gives a better estimate of the health of a population than death rate

• Accounts for health conditions like mental illness that rarely cause death

The Global Burden of Disease

Important to understand: • Leading causes of illness, disability, and death

in the world • Variations by age, sex, ethnicity, and

socioeconomic status • Changes over time

Table 2.3: The 10 Leading Causes of Death and DALYs

Source: Adapted with permission from Lopez AD, Mathers CD, Murray CJL. The burden of disease and mortality by condition: data, methods, and results for 2001. In: Lopez AD, Mathers CD, Ezzati M, Jamison DT, Murray CJL, eds. Global Burden of Disease and Risk Factors. Washington, DC and New York: The World Bank and Oxford University Press; 2006.

Table 2.3: The 10 Leading Causes of Death and DALYs (cont.)

The Global Burden of Disease

Causes of Death by Region • Higher income countries tend to have a greater

burden of noncommunicable disease • Lower income countries to have a greater

burden of communicable disease • Africa and South Asia are set apart by their

large burdens of communicable disease

Table 2.4: The Leading Causes of the Burden of Disease

Source: Reprinted with permission from Lopez AD, Mathers CD, Murray CJL. The burden of disease and mortality by condition: data, methods, and results for 2001. In: Lopez AD, Mathers CD, Ezzati M, Jamison DT, Murray CJL, eds. Global Burden of Disease and Risk Factors. Washington, DC and New York: The World Bank and Oxford University Press; 2006:91.

Table 2.4: The Leading Causes of the Burden of Disease (cont.)

The Global Burden of Disease

Causes of Death by Age• Children in low- and middle-income countries

often die of communicable disease • HIV/AIDS and TB are among the leading

causes of death among adults in low- and middle-income countries

Table 2.5: The 10 Leading Causes of Death in Children Ages 0-14, by Broad Income Group, 2001

Table 2.6: The 10 Leading Causes of Death in Adults 15-59, by Broad Income Group, 2001

The Global Burden of Disease

The Burden of Deaths and Disease Within Countries

In most low- and middle-income countries: • Rural people will be less healthy • Disadvantaged ethnic minorities will be less

healthy• Women will suffer from their weak social positions• Poor people will be less healthy• Uneducated people will be less healthy

Risk Factors

• Risk factor- an aspect or personal behavior or life-style, an environmental exposure, or an inborn or inherited characteristic, that, on the basis of epidemiological evidence, is known to be associated with health-related conditions considered important to prevent

• Most important risk factors in low- and middle-income countries are malnutrition, high blood pressure and high cholesterol, smoking, and unsafe sex

Table 2.8:The Leading Risk Factors for the Burden of Disease, 2001, Low- and

Middle-Income and High-Income Countries, Ranked in Order of Percent of Total DALY

Demography and Health

Population Growth • Majority of population growth will occur in

low- and middle-income countries • Put pressure on the environment • Create need for more infrastructure and

services

Demography and Health

Population Aging• Population of the world is aging • Implications for burden of disease because

people will be living longer with morbidities and disabilities

• Healthcare financing will be affected by change in ratio of working people to those over 65 years

Demography and Health

Urbanization• Majority of the world’s population lives in

urban areas for the first time • Enormous pressure on urban infrastructure like

water and sanitation

Demography and Health

The Demographic Divide • Highest income countries: low fertility,

declining populations, aging populations• Lowest income countries: relatively high

fertility, growing populations

Demography and Health

The Demographic Transition• Shift from pattern of high fertility and high mortality

to low fertility and low mortality• Mortality declines due to better hygiene and nutrition• Population grows with younger share of population

increasing• Fertility declines • Population growth slows and older share of

population increases

Figure 2.9: The Demographic Transition

Demography and Health

The Epidemiologic Transition• Shift from burden of disease dominated by

communicable disease to burden of disease dominated by noncommunicable disease

• Most low-income countries are in ongoing transition so they face large burdens of communicable and noncommunicable disease

Figure 2.10: The Burden of Diseae by Group of Cause, Percent of Deaths, 2001

Progress in Health Status

• Improvements in raising life expectancy and improving health not uniform across countries

• Life expectancy in South Asia and sub-Saharan Africa lag that in other regions

• Life expectancy in Europe and Central Asia changed little due to break-up of Soviet Union

• Life expectancy in East Asia has increased dramatically due to rapid economic growth

Table 2.11: Life Expectancy and Percentage Gain in Life Expectancy, 1960-2008, by World Bank

Region

Looking Forward

Economic Development• Economies of low-income countries need to

grow in order to invest in health • Impact of economic development will depend

on countries investing in areas that improve health such as water, sanitation, and education

Looking Forward

Scientific and Technological Change • Development of vaccines, drugs, and

diagnostics • Country’s ability to adopt these changes will

determine their effect on health

Looking Forward

Climate Change • Impact not entirely clear • Possible migration from places that become

inhabitable • Adverse weather • Possible change in populations of disease

vectors

Looking Forward

Political Stability • Necessary for long-term gains in health • Instability causes illness, disability and death

as well as breakdown of infrastructure and services

Looking Forward

Emerging and Re-emerging Infectious Disease

• Occurrence and impact difficult to predict • Pandemic flu• Anti-microbial resistance

Looking Forward

Projecting the Burden of Disease • Substantial changes from 2004 to 2030• Low- and lower-middle-income countries will

shift away from communicable disease • Causes associated with aging will increase in

importance • Mental health issues will increase in importance

The Development Challenge of Improving Health

• Health usually increases as national income increases

• Some countries have achieved higher life expectancies than their incomes would predict

• This is possible with investments in nutrition, education, good hygiene, and low-cost services that have a high impact such as vaccination programs