Week 3 Flashcards
WHO Definition of Health
Health is a state of complete physical, mental
and social well-being and not merely the
absence of disease or infirmity
The Natural Environment
1) Land
2) Air
3) Water
Components of the Epidemiological Triangle
1) Host
2) Environment
3) Agent
Causes of great epidemics
1) Urbanization
2) Increased human biomass
3) Concentration of poverty
4) Global Trade
5) Failure to safely dispose human waste
The Great Endemics (3)
1) Tuberculosis
2) Respiratory viruses and bacteria
3) Diarrheal viruses and bacteria
3 parts of IOM Public Health Definition
1) Mission
2) Substance
3) Organizational Framework
Mission of Public Health (IOM Definition)
The fulfillment of society’s interest in assuring the conditions in which people can be healthy
Substance of Public Health (IOM Definition)
Organized Community Efforts Aimed at the Prevention of Disease and Promotion of Health. It links many disciplines and rests upon the science of epidemiology
Organizational Framework (IOM Definition)
Both activities undertaken within the formal structure of government and the associated efforts of private and voluntary organizations and individuals
Ways public health improves medicine
1) Community Specific prevalence
2) Addresses access issues
3) Avoidance of numerator/denominator confusion
4) Hidden problems identified
5) Rewards of prevention reinforced
5) Addresses community-specific issues
6) Adds opportunity to use robust ecological model
Ways medicine improves public health
1) Identification of issues
2) Identification of system failures
3) Reminder of real world complexity
4) System entry point – local and personal
5) Use of clinical tools to address public health
problems
3 Essential public health services
1) Assessment
2) Policy Development
3) Assurance
Public Health Infrastructure
1) Government
2) Community
3) Organizations
4) Philanthropy
5) Workplaces
6) Medical Care System
7) Academia
Environment is where we:
Work, sleep and play
Current environmental threats
1) Air contamination
2) Water contamination
3) Land use
4) Persticides and Industrial Chemicals
Prevention paradox
Most individuals derive little or no benefit from prevention strategy
Timeline of a chronic, life threatening disease
Health-> disease onset->Illness onset->Complications-> Death
Primary prevention
Take action to eliminate precipitating causes of disease and injury before they happen. Outcome is no health event. (Between Health->disease onset)
Secondary Prevention
Screening Test. Detect and treat asymptomatic disease, or its predisposition, before it becomes symptomatic or does irreversible harm. Outcome is no symptomatic disease. (Between Disease onset->Illness onset).
Tertiary Prevention
Minimize risk of recurrence or clinical deterioration once a disease is diagnosed. (Between Illness onset->Complications)
5 Guiding principles of Clinical Prevention
1) Asymptomatic individuals are legitimate patients who deserve the
attention of busy clinicians
2) People who tend to seek out clinical preventive services are less
likely to benefit from them than people who do not
3) Far more people undergo preventive interventions than would ever
have developed the targeted health outcome without the
intervention
4) Preventive interventions are neither free nor harmless
5) For most people the benefits of prevention are never appreciated
because success is a non-event off in the distant future
5 Predictors of Succesful Clinical Prevention Programs
1) Target condition is associated with high morbidity and/or
mortality
2) Risk is unacceptable to the individual
3) Risk of future harm to an individual is predictable
4) Risk of future harm to an individual is modifiable in the
present
5) Preventive intervention is cost-effective
4 Clinical Preventive Services
1) Immunizations
2) Screening
3) Chemopreventive Agents
4) Lifestyle Counseling
6 Influences on Health Behavior
1) Free Choice
2) Biology
3) Culture
4) Social Position
5) Government
6) Healthcare
Screening cascade
Results after a screening test
PSA Testing
Prostate Cancer Screening is useless
USPSTF
U.S. Preventive Services Task Force
Distributive justice
How to ethically distribute resources among a population
Rationing
Distributing resources under conditions of extreme scarcity
The value problem
to provide higher quality care, with better outcomes, at a lower cost.
Value (formula)
Value = Quality/Cost
The fairness problem
to distribute health care goods and services fairly; to provide access to health care that does not unfairly disadvantage anyone
What does fee for service eat to?
More procedures
What does capitation lead to?
Fewer procedures
What does Capitation + Outcomes lead to?
Better clinical decisions
Unwarranted Variation
Variations that cannot be explained on the basis of illness, scientific evidence or well-informed patient preferences
Effective Care
Care that we know works and improves outcomes
Preference Sensitive Care
Care in which there is equal evidence on both sides of the intervention
Supply Sensitive Care
Care that is sensitive to the supply of medical care in an area
Bedside Rationing
Choosing a suboptimal treatment for a particular
patient based on cost (and not according to
standard guidelines)
Formal Principle
Equals must be treated equally
Material Principles (7)
Give content to formal principle and are:
1) To each an equal share
2) To each according to need
3) To each according to merit
4) To each according to effort
5) To each according to likely contribution to society
6) To each according to fair market exchange
7) To each in redress for past harms
Englehardt’s view (Libertarianism)
Fair processes of
exchange matter, rather than aiming at any desired
end state. —-Regarding the natural and social lottery, no obligations are created. It is unfortunate, but not unfair, that some lose the lottery.
Night watchman state
Idea by Englehardt. Libertarianism. Government should be minimal and only used to implement rules of acquisition and exchange (police, etc.) and to set up a military to protect against foreign invaders.
John Rawls idea of the Social Lottery (Qualified Egalitarianism)
Equal access to the
goods valued by rational actors, with inequality
tolerated only if it benefits least well off. —–The Original Position thought experiment shows that society should compensate for the outcome of the natural and social lottery.
Rawls’s First Principle of Justice
Each person is to have an equal right to the most extensive basic liberty compatible with a similar liberty for others (Vote, Political Office, Speech, No Arbitrary Arrest)
Rawls’s Second Principle of Justice (two parts)
1) Difference Principle: inequalities are to be of the greatest benefit to the least advantaged members of society
2) Opportunity Principle: offices and positions must be open to everyone under conditions of fair equality of
opportunity
Libertarian view of healthcare
Would largely view health disparities as “unfortunate but not unfair,” and would seek to address the issue through voluntary philanthropic activities.
Rawlsian view of healthcare
A well-ordered society would adopt policies that
“even out” the results of the natural and social lottery (even if they are no one’s
fault) in order to allow for an equality of opportunity and to benefit the least well-
off.
Health determinants (4 categories)
Individual behavior, Social Environment, physical environment, health services
Definition Crisis Standards of Care
Substantial change in the usual health
care operations and the level of care it is possible to deliver . . . justified by
specific circumstances and . . . formally declared by a state government in
recognition that crisis operations will be in effect for a sustained period
Primary principle (Institute of Medicine Reports)
Public health disasters justify temporarily adjusting practice
standards and/or shifting the balance of ethical concerns to emphasize the
needs of the community rather than the needs of individuals
Secondary Principles (8)
1) Duty to plan
2) Duty to care
3) Accountability
4) Duty to steward resources
5) Fairness
6) Consistency
7) Transparency
8) Proportionality
Typically, a pre-pandemic duty, but present even as a disaster unfolds.
Duty to plan (secondary principle)
Clinicians retain a duty to care, but shift in priority from caring for individuals to caring for populations
Duty to care (secondary principle)
Institutions and clinicians remain accountable for their actions. Allow for an appeal process before implementing a decision that adversely affects an individual patient(s)
Accountability (secondary principle)
Use resources with optimum efficiency
Duty to steward resources (secondary principle)
Allocate medical services solely to optimize community outcomes; vulnerable populations may require
additional resources
Fairness (secondary principle)
Relevantly similar patients treated similarly; care decisions not made for discriminatory reasons,
e.g., favoring certain religions, races, socioeconomic statuses.
Consistency (secondary principle)
Formalize criteria used for reallocation and publicize appropriately.
Transparency (secondary principle)
Burdensome policies must be commensurate with the scale of the disaster and risk to others.
Proportionality (secondary principle)
Main reasoning of University of Pittsburg Policy
Prioritization versus exclusion
1) does not categorically exclude any patients who, in usual circumstances, would
be eligible for critical care resources
2) allocation framework goes beyond simply attempting to maximize the
number of patients who survive to hospital discharge, because this is a thin conception
of doing the greatest good for the greatest number.
University of Pittsburg Policy Steps
Step 1: Calculate the SOFA Score
Step 2: Translate the raw SOFA score into 4-point scale
Step 3: Identify comorbidities of the patient at baseline. Severe comorbidities imply that the patient baseline health makes survival for one-year unlikely
Step 4: Add the scores from steps 2 and 3 to generate a prioritization score
Utilitarianism
Distribute goods to maximize the
overall quantity of goods in a society
Communitarian-Pluralist (Current)
Plurality of
material principles based on the practices that
evolved in the history in a community.
Unifying Principles
1) Libertarianism (Englehardt)
2) Qualified Egalitarianism (Rawls)
3) Utilitarianism
4) Communitarian-Pluralist (Current)
Ethical principles related to value problem (3)
1) Beneficence: We underuse effective care
2) Non-Maleficence: We overuse supply sensitive care, creating the potential for
iatrogenic injury
3) Justice: Money that is wasted cannot be spent on prevention, public health,
social services, etc., which tend to benefit the least well off.
Characteristics of Pittsburg Model
1) Resources assessed at least daily. Determination of which categories can
receive the scarce resource. 2) Not receiving scarce resource does not imply no disease directed therapy.
3) Ties are broken by life-cycle (age) considerations
4) Strict separation between treating team and triage team. 5) Appeal process available.
6) Health care providers and first responders given some priority.
7) Triage used both to allocate and to reallocate resources.
Choosing the most appropriate and effective intervention and achieving the best outcome
Quality
Types of Quality Problems (3)
- Misuse or avoidable errors in medical practice
- Overuse of unnecessary services
- Underuse of needed services
What Contributes to Quality Problems?
- Fragmentation in how health care system is organized
- Poor communication and coordination
- The way we pay for health care services
- Lack of evidence-based care and lack of consistent practice guidelines
- Disparities in access to care 6. Human error
- Systems errors more so than bad apples
- Medical malpractice system not designed to address systemic problems
STEEEP
We want a healthcare system that is:
- Safe
- Timely
- Effective
- Efficient
- Equitable
- Patient-Centered
How do we identify a quality problem?
- Measure the domains of misuse, overuse, and underuse
- Attend to problems in the STEEEP domains
- Monitor trends in performance over time
- Assess performance relative to an evidence-based
threshold - Compare U.S. performance to other countries
- Investigate variation regionally, between institutions, or between populations (i.e., disparities)
Medical errors estimate
Earliest estimate: 98k
Recent estimate: Between 210k-440k
Donabedian’s 3 categories for measuring Healthcare Performance
- Structure
- Process
- Outcome
Sructure (Donabedian)
Physical and organizational characteristics in settings where health care occurs
Process (Donabedian)
Care delivered to patients, such as services, diagnostics, treatment
Outcome
Effect of health care provision on the status of patients and populations
Challenges with Quality Measurement
- Cannot measure everything we care about with process
- Processes do not always predict outcomes
- Outcomes take time to measure
- We pay attention to what gets measured – may divert from other resources
- Costly to track and report measures for practices
- Multiple measures required for different agencies
- Takes time and money to update to keep up with best practices
Principles of Quality Improvement
- Focus on Systems and Processes
- Orient Toward Patients
- Measurement and Data Are Essential
- Invest in a Team Approach
Five Why’s
Used to identify causes of problems. You state a problem and then ask 5 why’s to reach the root of the problem
Affinity Diagram
Used to identify causes of problems. You use post-it notes to organize ideas into related groupings
Fishbone diagram
Used to identify causes of problems:
- Starts with the problem
at the head of the fish
2.Major branches correspond to a major cause (or class of causes) that directly relates to the effect - Minor branches correspond to more detailed causal factors
Flowchart
Used to problem solve a process: • Visualizes the sequence of events and decision points in a process • Identifies bottlenecks, delays, inefficiencies, redundancies, workarounds, breakdowns in communication, unnecessary complexity, and gaps in care
Swim lane diagram
Used to problem solve a process:
• Plot interconnections between processes, departments, and teams
• The swim lane flowchart identifies who does each step, not just what is done
• Discuss high-level process steps first, and then each team member documents his or her own individual work steps within a swim lane
• As team compiles detailed work steps, team members begin to understand each others’ work and can see the process from the patient’s perspective
Driver Diagram
Used to develop a solution: • Systematically plan your improvement project • State the aims • Identify 2-5 primary drivers to achieve that aim • Identify secondary drivers that influence the primary drivers • Brainstorm change ideas to address specific drivers to address the secondary and primary aims
PDSA Cycles
Used to test solutions:
- Plan
- Do
- Study
- Act
Plan (PDSA)
Determine tasks needed to
assess change, and predict
what will happen
Do (PDSA)
- Execute your plan • Collect data to measure change
* Observe what happens
Study (PDSA)
• Study the effect of the change
• Describe the results and how
they compared to the
predictions
Act (PDSA)
Describe what modifications to the plan will be made for
the next cycle from what you
learned
COVID-19 Attack Rate
– 75% if cohabitating with someone sick
– 10% if cohabiting with someone until they are
quarantined
– 5% if 15 minutes face to face with a confirmed
case
– < 5% if minimal contact
USA case fatality tase and CDC actual estimate
Case fatality: 0.046
CDC model estimate: 0.002-0.01
Transmission via aerosols (tiny respiratory droplets that can
remain suspended in the air)
Airborne spread
Infection status of virus (2)
Latent period, infectious period
Clinical status (2)
Incubation period, clinical period
Latent period
Time of infection to time individual becomes infectious
Incubation period
Time of infection to time symptoms first appear
Average number of individuals directly infected by an infectious case over the entire infectious period, when encountering a totally susceptible population in the absence of control strategies
Basic Reproductive Number (R0)
Basic Reproductive Number (R0)
Basic Reproductive Number (R0)Average number of individuals directly infected by an infectious case over the entire infectious period, when encountering a totally susceptible population in the absence of control strategies
R0=1
Disease will become endemic
R0>1
Disease will become epidemic
Determinants of R0 (formula)
R=cDp
c=number of contacts per unit time
D=Duration of infectiousness
p=Transmission probability per contact
Transmission probability per contact depends on 4 characteristics:
- Infectious source
- Infectious dose
- Susceptible Host
- Type of contact
Effective (Net) Reproductive Number (RN) & formula
Average number of secondary infectious cases produced by a typical infectious case as the epidemic evolves.
RN=R0*S
S=proportion of population that is susceptible
Herd Immunity
Collective immunity in a population
Herd Immunity Threshold (HIT) & Formula
Proportion of the population that must be immune in order for the disease to remain stable.
HIT=1-1/R0
Her immunity for COVID-19
About 50-70%
Herd immunity for COVID-19
About 50-70%
Management in a Pandemic
Joint response capabilities between public health agencies and their healthcare partners in key response categories: 1. Surveillance & Epidemiology 2. Command, Control & Communications 3. Risk Communication 4. Surge Capacity 5. Disease Prevention & Control
Herding cats
Individual physicians with idiosyncratic
beliefs
Key messages for pandemic risk communication
– The truth – What we know and don’t know – Forecast MUST include what eventually happens – What people should do – Reassure/prevent panic (without lying)
Disease Prevention Strategies for COVID19
• Contact Tracing (Based on testing & clinical
cases) • Isolation (for the sick) • Quarantine (for the exposed) • Pharmaceuticals & Vaccines (when available) • Social Distancing
Pretest probability for detecting covid
Population prevalence->Risk factors->Clinical Presentation
How to confirm diagnosis using test
Leading diagnostic: Choose test with high specificity to “rule in”
Active Alternative diagnosis: Choose tests with high sensitivity to “rule out”
Other diagnosis: Test for these only id leading hypothesis and alternatives disproved
Excluded diagnosis: no further testing
When is confirmatory (patient already presenting symptoms) testing most useful?
• When the pretest probability is well below 100%
• When confirming the presence or absence of the condition
would affect management
• When an accurate test is available
When is screening (patient not presenting symptoms) most useful?
• When the pretest probability is not too low or too high
• When confirming the presence or absence of the condition
would affect management
• When an accurate test is available
Components of pre-test probability (COVID-19)
Population prevalence Exposure history
Clinical presentation
Components of Effect on Management (COVID-19)
Patient
Potential contacts
Test Accuracy
Sensitivity
Specificity
Indirect method of detecting covid
Blood oxygenation, complete blood count, chest imaging
Direct methods of detecting covid
RT-PCR, Serology
Modes of COVID19 Supportive Treatment
- Close monitoring
- Supplemental 02
- Mechanical ventilation
- Fluid management
- Symptom Control
Modes of COVID 19 Directed Treatment
- Disruption of Viral Replication
2. Modulation of Immune Response
