CAPH Final

3 core functions of public health

Assessment

Policy development

Assurance

5-step process to addressing a public health issue in a community

1. Define the health problem

2. Identify risk factors

3. Develop and test interventions to address the problem

4. Implement the interventions

5. Monitor interventions to assess their effectiveness

Ecological model / Ecological Systems Theory

Individual beliefs and behaviors occur in a social context. 5 levels of influence.

1. Intrapersonal factors (beliefs, attitudes, self-efficacy)

2. Interpersonal relations (family, friends, coworkers)

3. Institutional level (workplace, school)

4. Community

5. Public policy

Health Belief Model

There are four factors that are likely to change behavior when faced with a health threat:

• the extent to which the individual feels vulnerable

• The perceived severity of the threat

• Perceived barriers to taking action to reduce the risk

• The perceived effectiveness of taking action

Transtheoretical Model / Stages of Change

Precontemplation

Contemplation

Preparation

Action

Maintenance

Institutional racism

Systematic racism. There is differential access to jobs, goods, services, etc

Personally mediated racism

Direct racist acts towards other people. (Think, person to person)

Internalized racism

The acceptance of racism and the boxes society has put marginalized people into on an individual level

By “when” prevention framework

Primary: preventing exposure to risk factors

Secondary: implemented after a disease has begun but before it is symptomatic (minimizing severity)

Tertiary: implemented after a disease is established (reduces disability)

By “who” prevention framework

Universal: preventions aimed at everyone

Selective: preventions aimed to those at risk

Indicated: preventions aimed to those already afflicted

True or false: controversies are bound with only some public health interventions

False, they are present with every public health intervention.

Why are there controversies associated with public health interventions?

Public health challenges the status quo

Potential for negative economic impact

Potential for the restriction of individual freedom

Moral and religious reasons

Political pressure

Relative poverty

Can’t afford the standard of living considered normal in one’s country. If the average annual income is higher in a country, the relative poverty line is also higher.

Absolute poverty

Can’t afford the basic necessities of life such as food

Doesn’t really exist in the richest countries

Compression of morbidity

Living a long healthy life and then die quickly

Epidemiology

The study of patterns of disease occurrence in human populations and the factors that influence these patterns.

It is the who, when, and where.

Biostatistics

Methods used to analyze and make sense of data

Social epidemiology

Studies social determinants of health. Identifies and addresses factors in the social environment related to health

FINER criteria for a good research question

Feasible

Interesting

Novel

Ethical

Relevant

PICOT criteria for a good research question

Population

Intervention

Comparison group

Outcome of interest

Time

Incidence

New cases over a period of time

Prevalence

Total number of cases in a population at a specific time

Rate

Cases/population at risk

Surveillance

Requiring certain notifiable diseases to be reported

Helps detect epidemics at an early stage

Permits measures to be taken to control the spread of disease

Involves data collection, analysis, and dissemination

Intervention Study

An experimental study. Typically, a randomized controlled trial, with some sort of blinding (single or double). It involves having an intervention and testing it on a group of people.

Cohort study

An observational and prospective study

Choose a large group of people, ask them detailed questions, then follow them over a certain time period.

Typically need a large sample and it is important to identify confounders

Framingham, Nurses’ Health Study

Case control study

A retrospective and observational study

Interviewing a case group and a control group and trying to determine what causes their differences.

Good for rare outcomes but prone to recall bias

Cross-sectional study

An observational one-time study.

Takes a “snapshot” of the health of a population.

If repeated, it can give an idea of time trends in a population

Confounding variables

Variables that are related to both the exposure and the outcome. They could completely account for the main relationship of interest.

Research with human subjects most follow these three primary ethical principles

Autonomy (informed consent)

Beneficence (researchers have to attempt to maximize benefits for participants and society while minimizing risk of harm to the individual)

Justice (equitable selection, no coercion)

Bacteria

Single celled organisms that grow and reproduce inside and outside the body

TB, cholera, strep, scarlet fever, E. coli

Viruses

Not complete cells (nucleic acid and protein). Reproduce by taking over other cells.

Smallpox, polio, hepatitis, HIV, rabies, common cold, yellow fever

Parasites

Single celled animals

Malaria, tapeworms

Prions

Strand of protein but no nucleic acid.

Mad cow disease

Methods of transmissions

Aerosols

Fecal-oral route

vector borne (from animals like insects)

Fomites (contaminated object like a doorknob)

Sexual contact (HIV)

Direct contact / bite (rabies)

Epidemiological Triad

Host, Agent (e.g., bacteria or virus), Environment

Vector in the middle

Chain of Infection

Pathogen → reservoir → place of exit → method of transmission → port of entry → susceptible host

Measles

Rash, fever, can cause serious complications in young children

Symptoms appear 7-14 days after contact

Highly contagious among those who are unvaccinated

Were declared eliminated in the US in 2000, but with vaccination rates decreasing there have been some outbreaks

By “how” prevention framework

Education

Motivation

Obligation/enforcement

Engineering

Social cognitive theory

People acquire new behaviors by observing others, interacting with their environment, and experiencing the consequences of their actions

Bobo doll experiment → children learn aggressive behavior by watching adults

Key assumptions:

Individuals are social beings

Individuals learn by observing others

Individuals can anticipate outcomes

Six core constructs:

Self efficacy

Observational learning

Outcome expectations

Behavioral capability

Reinforcements

Situation

Nongovernmental Organization (NGO)

A nonprofit nongovernment group who tries to fix social, environmental, or human rights problems

NIH

National Institutes of Health

It is the official medical research agency of the US and is part of the Department of Health and Human Services

What do screening tests need to be in order to be effective?

Highly sensitive and highly specific. Otherwise, there will either be too many false positives of false negatives

YPLL

Years of potential life lost

Estimate of the average years a person would have lived if they had not died prematurely

Sensitivity vs. Specificity

Sensitivity: is the test detecting the true cases (ability to rule out the false ones)

Specificity: is the test excluding the false cases (ability to include the true ones)

Ebola

Symptoms occur from day 1-3

Impaired organ function, internal and external bleeding (late stage)

Can be fatal if not treated

Current outbreak is difficult to control because there is no approved vaccine or therapeutics. There is also active armed conflict, and high population mobility

Incidence

The rate of new cases of a disease in a defined population over a specified period. The probability that a healthy person will get that disease

Prevalence

The total number of cases in a defined population during a specific time period

Relative Risk

Ratio of the incidence rate for the people exposed to the risk factor to the incidence rate for people in the unexposed group. Risk 1 means there is no association.

Odds Ratio

A ratio of two ratios that estimates the strength of the association between exposure and disease

DALY

Disability adjusted life years

measure of overall disease burden, it is the number of healthy years lost to a disease

Framingham Heart Study

determined the major risk factors for CHD:

Cigarette smoking

Hypertension

Low HDL cholesterol

Unintentional vs intentional injuries

Accidents vs. perpetrated by somebody

True or false: injuries follow predictable patterns, including disparities, and are often preventable

True

Three E’s of injury prevention

Education

Enforcement

Engineering

Occupational Injuries

Injuries that happen at work. Overlooked by the Occupational Safety and Health Administration (OSHA) as the regulatory agency

Personal stigma

self-disguist, shame, and self-hate

Social stigma

Isolation and rejection from friends and family

Institutional stigma

Unequal treatment in healthcare, the media, law enforcement, employers, government agencies, etc

Case fatality rate

The proportion of people who die from a specified disease among all individuals diagnosed with the disease over a certain period of time

Lethal means safety

Suicide prevention practice that involved making a suicide attempt method less available or more difficult to access

Endemic

The expected base rate of a disease/morbidity in a population

Epidemic

An outbreak of a disease in a specific population

Why is sampling important?

For generalizability