Determinants of Health

The third step in the public health approach to solving health problems: develop and test prevention strategies.

Before we talk about how to prevent something, we need to be clear on what exactly it is we are trying to prevent.

• we are trying to prevent the problem that we have identified, defined, and described in step 1 of the Public Health Approach. Generally speaking, it will be some type of communicable disease, some type of non-communicable diease, or some type of injury. It is helpful to know which category it belongs to because similar prevention approaches tend to work for problems in the same category.

Burden of Disease and Injury

Two ways to prevent disease or injury: eliminate the things that cause the disease (risk factors) or stop the natuarl sequence of eventsthat lead to bad outcomes. Both ways require us to think broadly about prevention. What exactly is "prevention"?

Prevention is the things we do to solve public health probelms. To solve a public health problem means to eradicate the things that get in the way of maximizing the health of the population and/or eliminating health disparities.

• in public health, it also refers to any effort to reduce the burden of disease or injury

Burden of a disease or injury (or other health condition) refers to the amount of healthy life lost across a defined population because of that particular disease or injury.

• "burden of disease" developed out of an aspiration to compare the total suffering in the world caused by every different kin of health condition. This is necessary becuase it helps us make decisions on where to devote resource.
• Comparing burden is tough because its hard to quantify the loss and suffering caused by each condition using the same unit of measurement.

One way to compare health conditions: look at the total years of healthy life lost due to each condition. This number is called the Disability Adjusted Life Years (DALYs). This metric combines measures of the suffering from mortality and morbidity across a population into one number, expressed inyears.

• Years of potential life lost because of premature death
• Amountof life lost to diminishedquality. (# years lived with a particular health condition discounted by a fration representing a reduction in quality of life lived during these years)

Prevention is the effort to reduce burden if disease/injury, so it encompasses:

• efforts to improve outcomes of health conditions (reduce likelihood fo death, reduce impairement)
• efforts to reduce the incidence of disease and injury so that fewer people are affected by them

How to prevent disease or injury

From the risk factors identified in step two of the Public Health Approach, we can now develop ways to address those risk factors and thereby lower the incidence of that disease in our population.

To address those risk factors, we can come up with interventions to help people reduce those risk factors. To create effective interventions, we must think about why people take on those risks. Behind every risk factor are the determinants of health, which refers to something that influences health outcomes. Determinants differ from risk beacuse it referes to the more "upstream" causes of morbidity and mortality that influence things down stream, like health outcomes and the presence of other risk factors.

We'll explore the determinants of health.

Social Factors

Smoking is a risk factor to lung cancer. We want to reduce this risk factor, so we must ask "why do peope smoke."

One reason are the social determinants of health- things about your social environment that can influence your health-related behaviors.

• You may smoke because of your friends and families do it (social network), you may be stressed, it may be the social norm, and it may be completely legal.

In cities across the US, we saw that areas with high income levels have higher education and employement levels and also higher life expectancies. The vise versa is also true.

• Income, education, and occupation all influence our health and each other.
• These factors combined are called one's socioeconomic status, a concept that describes one's place in society relative to one another. It determines one's life expectancy.

There's no one way to measure socioeconomic status. Finding the status of an individual requires collecting a different data than finding the status of an entire population. Data points can serve as proxies or substitutes for socioeconomic status.

Racial segregation in Baltimore historically is a result of discriminatory practices that date to the middle of the last century.

• Segregation of living locations were done through "redlining", which was the encouragement of denying mortgages to Blacks. Home ownership is a major source of wealth.

Environmental Factors

Other influences of lung cacner include living with someone else who smokes (second-hand smoke), ambient air pollution, or occupational exposures.

The environment refers to everything outside the body including the natural and built environment. Environmental health is the field fo study on understanding the effect of environmental factors on health. they study both disease and injury outcomes.

In order for something in the environment to harm a person's health, it has to follow a path:

1. Hazard: something that can cause harm is present in the environment. E.g., toxins,r adiation, partcles, chemicals
2. Pathway: transported through environmental pathways. E.g., air, water, soil, food, etc.
3. Exposure: the hazard enters the human body through routes of exposure like inhalation, ingestion, or absorbsion
4. Disease: variety of negative health effects results. E.g., cancer, neurological damage, lung disease, etc.

The environmental determinants of health are things taht allow hazards to be present in our environment in the first place.

Conceptual Models

The ecological model of health behavior, or the social-ecological mdoel is a tool to viulize the relationships beteen the factors that determine health outcomes.

conceptual models (or frameworks) are abstract depictions of the relationship between various concepts that are involved in a process/sstem.

• useful for helping visuzlize the complex relationships and interactions between health determinants, risk factors, and health coutcomes

The epidemiologic triad models the relationship between a hazard (agent), the enviornment it is found, and the way the agent and environment interact with us (hosts). and in the middle is the vector/vehicle

• disease/injury results from an interaction between the host, agent, and environment.
• we can look and think about the different risk factors that play a role in the problem because every part of the model contributes to the probelm (therefore we can target it and start prevention efforts in any aspect of it. )

Another well-known model is the ecological model of health behavior (social-ecologicla model). It reminds us of the factors at different levels that contribute to an indivdual's risk of disease.

read Glanz and Kahan Conceptual Framework for Behavior Change.pdf to learn more.