public health mods+lectures

Public Health

A field that focuses on the health of populations. It aims to **prevent disease and promote well-being through organized community efforts .... Other fundamental qualities include a focus on real-world problems, evidence-based decision making, a prevention focus (especially primary prevention), organized and collaborative efforts, and a systematic approach

Civil Discourse

The practice of deliberating about matters of public concern in a way that seeks to expand knowledge and promote understanding. Its aim is also to develop mutual respect, build civic trust, and identify common ground on matters of public concern.

Public Health Problem

Anything that significantly gets in the way of maximizing the health of the population or eliminating health disparities. identified and prioritized using data from sources like surveillance, descriptive epidemiology, burden of disease measures, and economic costs.

Public Health Approach

A systematic process for solving health problems. It involves four steps: 1. Identify or Define the Problem, 2. Identify Risk & Protective Factors, 3. Develop & Test Prevention Strategies, and 4. Assure Widespread Adoption. This is often a continual process.

identify or define the problem

step 1 of public health approach

identify risk and protective factors

step 2 of public health approach

develop and test prevention strategies

step 3 of public health approach

assure widespread adoption

step 4 of public health approach

Burden of Disease

Refers to the total loss caused by a particular health condition. It includes mortality (loss of life), morbidity (the state of being diseased or unhealthy), composite measures that combine mortality and morbidity, and economic costs. This measure is used to help prioritize public health problems when resources are finite.

Mortality

Represents the loss of life caused by a health condition. It is often measured by the number of lives lost, fatality rates (usually presented per 100,000), or Years of Potential Life Lost (YPLL).

Years of Potential Life Lost (YPLL)

A measure of premature mortality. It is calculated based on the age at death and a standard life expectancy, giving more weight to deaths that occur in younger age groups. For example, if life expectancy is 75 years, a death at age 35 contributes 40 __, while a death at age 65 contributes 10 _. This helps answer whether all deaths should be weighted equally.

Morbidity

The state of being diseased or unhealthy within a population. It is often measured by the number of non-fatal cases, incidence rates, or prevalence rates. Severity (how bad it is to live with the condition) is also a component

Incidence Rate

The rate at which new cases of a disease occur in a population over a specified period. It is calculated by dividing the number of new cases by the population size and typically presented per a unit of population, such as per 100 or per 100,000.

compare burden of disease

why is incidence rate crucial for comparing dif pops (unlike just comparing case counts)?

Prevalence Rate

The proportion of a population that has a particular disease or condition at a specific point in time or during a specified period. It reflects the total number of existing cases, both new and old, in a population at a given time.

Disability Adjusted Life Years (DALYs)

A composite measure that combines years of potential life lost (YPLLs) with years lived with disability (YLDs). It involves assigning "quality" values for different health states, usually ranging from 0 (death) to 1 (optimal health), and multiplying the time spent with a condition by its health state value. This measure allows for adjusting years lived based on the "quality" of those years.

counts

represent the total number of cases observed.

rates

relate the number of cases to the size of the population, often over a specific time period. are preferred for comparing health outcomes across different populations because they account for population size, whereas counts alone can be misleading.

Risk Factor

Something that contributes to an outcome. Specifically in public health, it is something that increases the likelihood of a negative health outcome.

Protective Factor

Something that contributes to an outcome. Specifically in public health, it is something that decreases the likelihood of a negative health outcome.

Epidemiologic Triad

A conceptual model that describes how disease or injury results from an interaction between the host (susceptible human), agent (cause), and environment (physical and social). It also often includes a Vector or Vehicle (a carrier or intermediary). This model helps identify potential intervention points.

Vector

A carrier that transmits an infectious agent. In the case of Lyme disease, the tick

Cohort Study

An observational study design used to test hypotheses about risk and protective factors. It follows a defined healthy population (or groups defined by exposure status) over time to compare the incidence of disease in exposed and non-exposed groups .... It allows for the calculation of relative risk (RR).... Participants are not assigned to exposure groups; exposure occurs naturally .... An example is comparing the incidence of Lyme disease in homeowners with dogs vs. those without dogs

Case-Control study

used to test hypotheses about risk and protective factors ....

• compares a group of individuals with a disease (cases) to a group without the disease (controls)

• The study assesses prior exposure to potential risk factors in both groups

• It allows for the calculation of the odds ratio (OR) .... An example is comparing the odds of hiking frequently among people with Lyme disease vs. those without Lyme disease

Behavior Change Intervention

An intervention that aims to change what people do so that they do the healthier or safer thing. These are considered "active protection" because people have to actively do something to be protected. Designing these requires understanding behavioral science and how to reach the target population.

Environmental/Technological Intervention

An intervention that changes the world around people so that they are protected from disease or injury. These are considered "passive protection" because people do not have to do anything to be protected. Designing these involves engineering principles and incorporating safer designs.

Primary Prevention

Prevention strategies that aim to prevent the disease or injury process from starting. This is generally done by limiting exposure to harmful things. It is the best-case scenario and always preferred whenever possible87 .... Examples include wearing seatbelts or avoiding activities in wooded areas where ticks are prevalent

Secondary Prevention

Prevention strategies that aim to prevent full-blown disease or injury after the disease or injury process has already started .... This often involves early detection/screening and early intervention .... An example for Lyme disease is identifying a tick bite or initial rash and starting treatment

Tertiary Prevention

Prevention strategies that involve medical treatment and rehabilitation after a disease or injury has occurred. The goal is to reduce the impact of the disease/injury and prevent complications or long-term disability .... An example for Lyme disease is managing persistent symptoms

Policy

A course or principle of action adopted or proposed by a government, party, business, or individual. It consists of the written or unwritten aims, objectives, targets, strategy, tactics, and plans that guide actions. In public health, policies often aim to improve the health of the population. They are typically mandatory rules made by agencies and organizations, both public and private. Examples include legislation, regulations, taxes, and fees.

Program

A description or plan of action for an event or sequence of actions over a short or prolonged period. It's a more formal outline of how a system or service will function, with specifics like roles, responsibilities, expenditures, and outcomes.

• refer to mechanisms through which services like education, assistance, or incentives are provided, often on a voluntary basis.

Policy Analysis

A process to assess and compare different policy or program options ("alternatives"). The goal is to determine which option will best achieve stated goals based on selected criteria. The steps involve stating goals, selecting criteria (like effectiveness, affordability, implementability, social acceptability, political acceptability), and then assessing and comparing the options against those criteria.

Effectiveness (of a policy)

One key criterion used in policy analysis. It assesses how likely an intervention (or policy/program) is to solve the problem. Evidence for effectiveness can come from intervention studies or examples from other places.

Affordability (of a policy)

One key criterion used in policy analysis. It assesses how much it will cost to implement an intervention (or policy/program). This involves cost analysis and considering budget constraints.

Community Based Participatory Research (CBPR)

A research approach that involves full collaboration with the community at all stages of the research process. In this model, the community defines the issues and research questions, creates data collection tools, recruits participants, collects and analyzes data, disseminates findings, and generates and carries out action plans. It contrasts with traditional research where researchers primarily design the study and questions, and the community provides answers. A CBPR approach can be particularly useful for addressing complex community issues.

Traditional Research

A research approach where researchers design the study and questions, and the community's primary role is to answer questions. Researchers typically conduct the data collection, analysis, dissemination, and design interventions based on findings, with potentially some community input on generating solutions.

Health Care System

A complex set of organizations, institutions, and resources organized to deliver health care services. Public health is concerned with the system's overall ability to maximize access and quality while keeping costs low.

Intervention Studies

Studies designed to evaluate whether a specific action or intervention is effective. They ask questions like, "Does X prevent Y?" or "Is X associated with improvement in Y?". Common designs include experimental studies (randomized controlled trials) and quasi-experimental studies (observational studies)

Experimental Studies (Randomized Controlled Trials)

An intervention study design where participants are randomly assigned to an intervention group or a control group (who receive no intervention or standard care). This design helps to assess the true effect of the intervention by minimizing bias from confounding factors. An example is randomly assigning residents to receive a fire safety program or not and comparing fire safety practices.

Quasi-Experimental Studies (Observational Studies)

An intervention study design used to evaluate the effect of an intervention when random assignment is not possible or ethical .... These studies often compare outcomes in a group that received the intervention to a group that did not, or compare outcomes in the same group before and after the intervention.... An example is comparing residential fire death rates before and after a building code change requiring sprinkler systems is implemented

Surveillance

The routine, systematic collection and analysis of data. Surveillance data is a key methodological approach in public health, particularly in Step 1 (Identify the Problem) of the public health approach.

Descriptive Epidemiology

**The study of the distribution of health-related states or events in specified populations49 . It involves examining who is affected, what the health outcome is, when it occurs, and where it is happening49 . Descriptive epidemiology, using surveillance data, is crucial for identifying and defining public health problems in Step 1 of the public health approach

Hazard, Pathway, Exposure, Disease Model

A conceptual model used particularly in environmental health investigations. It describes how a Hazard (like a chemical or pathogen) can travel through a Pathway (like municipal water or air) leading to Exposure (like ingestion or inhalation), which can then result in Disease (like watery diarrhea or bronchiolitis obliterans). This model helps identify how environmental factors make people sick

Goals/Aims of Public Health

The two overarching goals of public health are to **maximize the health of the population** and **eliminate health disparities**. These goals are fundamental to public health efforts. Anything that significantly prevents achieving these goals can be considered a public health problem.

Core Functions and Essential Services of Public Health

These are the **activities that public health undertakes to achieve its goals** of maximizing population health and eliminating health disparities. While too numerous to list exhaustively, examples include **providing vaccinations, issuing nutrition guidelines, setting safety standards for motor vehicles, monitoring air pollution levels, and regulating tobacco sales**. These activities are performed by various public health agencies and organizations.

Public Health Infrastructure

This refers to the **agencies and organizations that perform activities supporting the core functions and essential services of public health**. In the United States, there are many key components to this infrastructure, including government agencies and nongovernmental organizations. Understanding the relationships between these components is crucial for understanding public health.

Identify or Define the Problem

This involves determining what issues are significantly getting in the way of maximizing the health of the population or eliminating health disparities. Data on deaths (like leading causes) and non-fatal health conditions (like arthritis prevalence) are used in this step to identify problems. Using data breakdowns can help define problems more specifically, such as identifying "fentanyl-related deaths in the Baltimore Metro area" as a key problem.

Health

The concept of health is more complex than simply being "not-sick". You can work to improve your health even when you are not sick. Measures of well-being, while seemingly simple, are **subjective**, time-consuming and costly for large populations, capture only individual importance (not societal), and **do not provide actionable information** about specific things to improve health. Public health often quantifies health by looking at sickness.

Quantifying Sickness

In public health, quantifying sickness means determining the **number of people in a population who are sick and with what ailments**. Multiple methods can be used to obtain this information, including looking at **medical records** to count diagnoses (though this misses those who don't visit the doctor), conducting **surveys** of the population (which can capture conditions not leading to a doctor visit), and requiring healthcare providers to **report cases of certain diseases to the government** (notifiable diseases).

Notifiable Diseases

These are generally **highly contagious and very serious diseases that healthcare providers are required to report to the government**. Reporting these diseases allows public health officials to know quickly when they appear and act fast. COVID-1

Measuring Health using Deaths

Using data on deaths is a common way to measure health in public health. This is because there is generally **access to good, complete, and reliable data on deaths**. Deaths are almost universally documented on death certificates, and this information is compiled into large databases by central agencies. Death as a "health state" is considered **unambiguous**, unlike living with a health condition where experiences can vary greatly between individuals with the same diagnosis. This data is useful for identifying public health problems.

Leading Causes of Death

These are the health conditions or events that people in a population **die from the most**. They are identified by counting the number of deaths attributable to each cause and ranking them from most to least frequent. In the U.S. in 2020, the top 10 leading causes included Heart Disease, Cancer, COVID-1

Non-Fatal Conditions

observing this helps stop overlooking the impact of health conditions that people are mostly living with. These _______ can significantly affect the quality of life of millions of people. Data from surveys and medical records can be used to identify the leading causes of these ________. For example, arthritis is a _______ affecting a large portion of the U.S. population and causing activity limitations.

National Center for Health Statistics (NCHS)

The NCHS is a division within the CDC that is responsible for **collecting and compiling mortality data** through the National Vital Statistics System (NVSS). They collect this information from death certificates. In addition to mortality data, the NCHS also collects information on **non-fatal health outcomes** and maintains several other public health data systems.

National Vital Statistics System (NVSS)

This is the system through which the **National Center for Health Statistics (NCHS) collects mortality data**. The data is obtained from death certificates.

CDC WONDER

A **public interface offered by the CDC** that allows users to **query the U.S. mortality database**. This tool enables users to obtain data on deaths based on various parameters, such as cause, location, demographic characteristics, and time period, allowing for tailored mortality data.

MMWR, NCHS

Information about non-fatal health outcomes can be found from various sources. The CDC website is a general resource for information on all kinds of health conditions. The CDC’s A-Z Index is a useful starting point for finding information on specific health topics, including risk factors and prevention strategies. ____ published weekly by the CDC, contain tables and figures with data on health conditions. Additionally, the ____ maintains various public health data systems that collect information on non-fatal outcomes, such as the National Health Interview Survey (NHIS) and the National Health and Nutrition Examination Survey

Morbidity and Mortality Weekly Reports (MMWR)

These are **reports published every week by the CDC**. They typically contain numerous tables and figures presenting data on various health conditions and topics. They are a source of data on both fatal and non-fatal health outcomes.

Prevalence

proportion of persons in a population who are living with the disease, injury, or risk factor of interest at a specified point in time. It counts all ongoing "cases" in the population at that moment, regardless of when the condition began.

Identify Risk & Protective Factors

This step follows identifying or defining the problem. It involves understanding the determinants of the health condition, including causes and factors that increase risk (risk factors) or decrease risk (protective factors). This step is closely related to Step 3 (Developing & Testing Prevention Strategies) as identifying these factors is necessary for addressing them. Epidemiology, specifically risk factor studies, is used to identify these factors.

Determinants

In epidemiology, determinants are defined as the **causes of a health condition or things that increase one’s risk for that health condition**. Risk factors are a type of determinant. Step 2 of the Public Health Approach involves identifying risk and protective factors (determinants). Public health uses conceptual models, like the Social-Ecological Model, to visualize and understand the complex relationships between determinants, risk factors, and health outcomes. Determinants can range from immediate risk factors to broader social and environmental factors.

Risk Factor

type of determinant that increases one's risk for a health condition. focus of Step 2 of the Public Health Approach. Epidemiology is the method used to identify these. Examples include smoking > lung cancer.

Risk

refers to the probability that harm will occur.

typically measured by calculating the incidence rate of the health condition of interest in the population.

Incidence Rate

the proportion of the population of interest who develop a disease or injury during a specified period of time. It is calculated by dividing the number of new cases in the population during the time period by the total population at risk during that period.

• used to measure risk and is a key component in calculating Relative Risk in cohort studies.

Cohort Study

A type of risk factor study design that starts with a defined healthy population and follows them over time to compare the incidence of disease or injury in individuals who are exposed to a factor versus those who are not exposed. In a ____, participants are not assigned to exposure groups; the exposure occurs naturally. The primary measure calculated in a _____ is the Relative Risk (RR). A _____ can investigate whether exposure to a factor causes an outcome.

Relative Risk (RR)

**A measure calculated in cohort studies** to quantify the association between an exposure and a health outcome. It is the **ratio of the incidence rate of the outcome in the exposed group to the incidence rate in the non-exposed group**. An RR > 1 suggests the exposure is associated with an increased risk of the outcome in the exposed group compared to the non-exposed group. For example, an RR of 20 for smoking and lung cancer means the incidence of lung cancer is 20 times greater in smokers than in non-smokers, or smokers have a 20 times higher risk.

Case-Control Study

A type of risk factor study design that **starts by identifying individuals with a disease or injury (cases)** and then selecting a comparison group of **healthy individuals without the disease (controls)**. The study then **compares the past exposure** to a potential risk factor in the cases versus the controls. The primary measure calculated in a case-control study is the **Odds Ratio (OR)**. This design is often used when the disease is rare or has a long latency period.

Odds Ratio (OR)

**A measure calculated in case-control studies** to quantify the association between an exposure and a health outcome. It is the **ratio of the odds of exposure in cases to the odds of exposure in controls**. The odds of exposure in cases is calculated as the number of exposed cases divided by the number of unexposed cases. The odds of exposure in controls is calculated as the number of exposed controls divided by the number of unexposed controls. An OR > 1 suggests the exposure is associated with higher odds of the outcome.

Develop & Test Prevention Strategies

This step follows identifying risk and protective factors. It involves figuring out what actions can be taken to address the identified public health problem and testing whether these actions are effective. Developing interventions can be informed by behavior change theories when behavioral change is the goal. Testing interventions involves studies like experimental (RCTs) or quasi-experimental designs. This step is crucial because it provides information needed to decide whether to implement an intervention more widely (Step 4).

address risk factors, interrupt progression of disease/injury

Public health professionals think about preventing disease or injury in two main ways

Interrupting the Progression of Disease/Injury

This is one way of thinking about preventing a health condition. It involves understanding the **natural phases a disease or injury process goes through** and identifying points within that progression where interventions can stop or alter the outcome. The general principle is that **intervening earlier in the process is likely to lead to better health outcomes**. Conceptual models illustrating these progressions are used to identify intervention points.

Progression of Disease/Injury (Conceptual Model)

A useful conceptual model that represents the **natural phases through which a disease or injury process progresses**. While the specifics differ for communicable diseases, non-communicable diseases, and injuries, the generalized model shows **Exposure** leading to the **Disease/Injury Process Starting** (after a Latency/Incubation Period), followed by **Disease/Injury Symptoms**, and potentially resulting in **Death or Recovery/Non-Fatal Outcome**. Understanding this progression helps identify points for primary, secondary, and tertiary prevention.

Primary Prevention

In the context of the progression of disease/injury, primary prevention aims to **prevent the disease/injury process from starting**. This is generally achieved by **limiting exposure to harmful things**. In the injury model, primary prevention prevents the "Event". In the communicable disease model, it prevents "Transmission". In the non-communicable disease model, it prevents "Accumulation". Examples include smoking cessation, promoting healthy diet/exercise, sunscreen use.

Secondary Prevention

aims to prevent full-blown disease/injury after the disease/injury process has already started. This often occurs during the latency or incubation period, before symptoms appear. In the injury model, prevents the "Injury" during an "Event". In the communicable disease model, it prevents symptoms from showing during the incubation period. In the non-communicable disease model, it involves screening to detect early stages and intervening to prevent more advanced disease. Examples include cancer screenings, cholesterol/blood pressure screenings with medication or lifestyle changes.

Tertiary Prevention

In the context of the progression of disease/injury, occurs after disease/injury symptoms appear. It involves providing medical treatment to prevent death or complications and, depending on the condition, to restore functioning or maintain the best possible health. In the injury model, aims to prevent "Death" and result in "No Death (But Temporary or Permanent Disability)". In the communicable disease model, it involves treating symptomatic individuals, ideally leading to recovery. In the non-communicable disease model, it aims to prevent "Death" and result in "Maintenance". Examples include surgery, chemotherapy, radiation, medications.

Conceptual Model / Conceptual Framework

abstract depictions that visualize the relationships between various concepts involved in a particular process or system. In public health, they are incredibly useful for understanding the complex relationships between health determinants, risk factors, and health outcomes. They help identify important factors and show how they are expected to interact. Examples include the Epidemiologic Triad and the Social-Ecological Model, as well as models illustrating the progression of disease/injury.

Social-Ecological Model

A conceptual model that **expands upon the Epidemiologic Triad** by explicitly identifying multiple levels of environmental factors that can influence health. It views the individual (host) within nested levels of environment. This model is helpful for identifying both immediate risk factors and more upstream determinants of health. The levels are typically represented as concentric rings and include the **Individual, Interpersonal (Family & Friends), Institutional (Workplaces, Schools), Community (Neighborhood Setting, Local Economy), and Society (National & State Policies, Social Norms)**. Prevention strategies can address factors at any of these levels.

Social Determinants of Health

These are the **things about an individual's social environment that can influence their health**. They are factors situated within the levels of the Social-Ecological Model outside of the individual. A key example discussed in the sources is **socioeconomic status**. Social determinants are often linked to geographic location and can contribute to health disparities.

Socioeconomic Status (SES)

Socioeconomic status is a complex concept often characterized by factors such as **income level, education level, and occupation**. In public health, SES is often assessed for whole populations or communities rather than just individuals. Since direct measures like average income or education level for a neighborhood might be difficult, **proxies or substitutes** are often used, such as the percentage of the population that completed high school, home ownership rates, eligibility for free school lunch, or employment rates. SES is generally seen to have an association with health outcomes. Differences in SES across communities can be linked to factors like racial segregation, which is a result of discriminatory practices.

Environmental Factors

These are factors that are **outside the body** and can influence health outcomes. They include both the **natural environment** (like ambient air pollution) and the **built environment** (like buildings, infrastructure, or even personal items like clothes or toothpaste). Environmental factors are often tied to where a person lives. For example, areas with lower socioeconomic status tend to have higher levels of air pollution, which in turn are associated with higher rates of related health outcomes like asthma. These factors are considered determinants of health.

Interventions

In the context of the Public Health Approach, interventions are the **strategies or actions developed and tested to address a public health problem**. Developing interventions often involves using models, such as behavior change theories, particularly when the goal is to change people's behaviors. Testing interventions is crucial to determine their effectiveness before widespread implementation. This testing is done through intervention studies, like experimental or quasi-experimental designs. Interventions are part of Step 3 of the Public Health Approach.

Behavior Change Theories/Models

Theoretical frameworks that attempt to **explain why people do what they do**. These models are useful in public health for **developing interventions aimed at changing health-related behaviors**. By understanding the factors influencing behavior, public health professionals can identify specific aspects to target with an intervention. There is no single perfect model, so the most fitting one is chosen for the specific intervention being designed. An example discussed is the **Health Belief Model**.

Health Belief Model

A specific **behavior change theory** that describes the factors influencing a person's likelihood of taking a particular health-related action. The model posits that this likelihood depends on the individual's **perceived threat** of the disease/injury, the **perceived benefits** of taking action, the **perceived barriers** to taking action, **cues to action**, and **self-efficacy**. Perceived threat is a product of perceived susceptibility and perceived severity. A person is more likely to act if perceived benefits outweigh perceived barriers.

susceptibility and severity

What is perceived threat determined by? Perceived threat is an assessment of how much of a health threat a disease or injury is. A higher perceived threat increases the likelihood of taking action to prevent it.

Perceived Susceptibility (Health Belief Model)

Within the Health Belief Model, this refers to an individual's belief about the chances that a particular disease or injury will happen to them. It is one of the two components contributing to perceived threat. For example, a flu prevention campaign might aim to increase students' ________ to catching the flu.

Perceived Severity (Health Belief Model)

Within the Health Belief Model, this refers to an individual's **belief about how bad it would be if they did happen to get a particular disease or injury**. It is one of the two components contributing to perceived threat. For example, a flu prevention campaign might aim to increase students' perceived severity of catching the flu.

Perceived Benefits (Health Belief Model)

In the Health Belief Model, this refers to an individual's **belief about what good taking a particular health-related action will do**. If the perceived benefits of taking action are greater than the perceived barriers, the individual is more likely to take the action. For example, the perceived benefit of getting a flu shot is not catching the flu.

Perceived Barriers (Health Belief Model)

In the Health Belief Model, this refers to an individual's **belief about how hard or costly it will be to take a particular health-related action**. If the perceived barriers are greater than the perceived benefits, the individual is less likely to take the action. Examples of barriers might include the inconvenience or cost of getting a flu shot.

Cues to Action (Health Belief Model)

In the Health Belief Model, these are **signals that can increase the likelihood of a person taking a particular health-related action**. They serve as reminders or prompts to engage in the desired behavior. For example, signs posted on campus reminding students that a flu clinic is happening that day are cues to action.

Self-Efficacy (Health Belief Model)

In the Health Belief Model, this refers to an individual's **belief in their ability to successfully perform a particular behavior or action**. If a person does not believe they can do something, they may not even try. A higher sense of self-efficacy increases the likelihood of taking the action. For example, flu clinic signs might implicitly suggest that getting a flu shot is easy enough for anyone to do, potentially reinforcing self-efficacy.

Experimental Study Design (Randomized Controlled Trial - RCT)

A study design used to test the effectiveness of interventions. It involves recruiting participants, collecting baseline measurements, and then **randomly assigning** them to either receive the intervention (treatment group) or not (control group). Random assignment is a key characteristic. After the intervention period, follow-up measurements are collected, and the outcomes are compared between the groups. While powerful, this design is **not always feasible for public health interventions that are delivered to whole communities** rather than individuals.

Quasi-Experimental Study Design

A study design used to test the effectiveness of interventions, particularly when **random assignment of individuals is not possible**, which is often the case for community-level public health interventions. This design involves comparing an intervention group to an existing control group that is similar but does not receive the intervention. Data is collected from both groups **before the intervention (baseline)** and again **after the intervention (follow-up)**. The effectiveness of the intervention is assessed by **comparing the change in the outcome measure from baseline to follow-up** between the intervention and control groups. These are also referred to as "observational studies" when used for intervention evaluation.

Assure Widespread Adoption

This step follows the development and testing of prevention strategies in Step 3. Based on the results of intervention testing, if an intervention is found to be effective, public health professionals would want to expand its implementation, potentially scaling it up to other communities or nationally. Conversely, if testing reveals an intervention is ineffective, resources would not be used to replicate it.

Public Health vs. Medicine

Public health and medicine have distinct focuses. **Public health focuses on populations**, aiming to improve health outcomes for groups of people. **Medicine, in contrast, focuses on individual patients**, providing care and treatment to one person at a time. Public health tends to emphasize **primary prevention**, stopping conditions before they start, while medicine often focuses more on **treatment** for existing conditions. Despite these differences, they intersect significantly, as public health is concerned with the healthcare system where medical care is delivered.

access, cost, quality

3 traits of good healthcare system

Major Issues with Health Care Systems

Access to health care, the Quality of care provided, and the Cost of health care.

price x quantity

The cost of health care. Pricing in the U.S. is complex, often influenced by market forces and negotiations between insurers and providers, with uninsured patients potentially facing higher charges. Ways to control costs include reducing utilization or reducing prices. Government approaches can involve increasing competition or setting price limits for public insurance plans. Reducing utilization is challenging due to new technologies and payment systems like fee-for-service.

Health Care Utilization (Quantity)

Refers to the **quantity of health care services being consumed** by an individual or a population. It can pertain to the overall amount of care or specific types of care. Reducing health care utilization is one strategy for controlling costs. However, reducing utilization can be difficult without rationing and is influenced by factors like new medical technologies and payment structures that incentivize providing more care, such as fee-for-service.

Fee-for-Service

A payment system commonly used for doctors in the U.S., where they **get paid each time they provide a service or care**. This system **incentivizes doctors to provide more care** because doing so increases their earnings, creating no incentive to limit the amount of care provided. This is identified as one reason why lowering health care utilization in the U.S. is difficult.

Defensive Medicine

The practice by doctors of **ordering more diagnostic tests** or providing more care than might be strictly necessary. This behavior is often driven by the **fear of malpractice lawsuits**, where a misdiagnosis leading to a bad outcome could result in legal action. Defensive medicine contributes to increased health care utilization.