Public Health Flashcards
3 domains of public health
PIS
Health protection (control infectious diseases / environmental hazards)
Health improvement (social interventions aimed at preventing disease / promoting health / reducing inequality)
Health services (organisation and delivery of safe, high quality services)
Inverse care law
The availability of medical or social care tends to vary inversely with the need of the population served
Determinants of health
PROGRESS:
Place of residence
Race/ethnicity
Occupation
Gender
Religion
Education
Socio-economic status
Social capital/resources
Horizontal vs vertical equity
Horizontal = equal treatment for equal need e.g. two identical twins with same level of asthma get same treatment
Vertical = unequal treatment for unequal need e.g. one person with life threatening asthma vs one person with mild asthma get different treatment, or the UK tax system
Health needs assessment definition
A systemic approach for reviewing health issues which leads to agreed priorities and resource allocation to improve health and decrease inequalities (takes into account need, demand, supply)
Epidemiological health needs assessment definition
Disease incidence & prevalence
Morbidity & mortality
Life expectancy
Services available (location, cost, utilisation, effectiveness)
Limitations of a epidemiological health needs assessment
Data availability may be poor
May be inadequate evidence base / quality of evidence
Reinforces a biomedical model of care / doesn’t consider felt need
Comparative health needs assessment definiton
Compares services received by one population to another
Spatial (e.g. different towns) or social (e.g. age, social class)
Evaluates variation in performance/costs of services
Comparative health needs assessment limitations
Data available may vary in quality
May be hard to find comparable population
Comparison may not be perfect
Corporate health needs assessment definition
Takes into account views of any groups that may have an interest e.g. patients, health professionals, media, politicians
Example of data collection = focus groups
Corporate health needs assessment limitations
May be hard to distinguish need from demand
Groups have vested interest - leads to bias
Dominant individuals may have undue influence
Types of need in health needs assessment (4) / Bradshaw taxonomy of social need
FENC
Felt need
Expressed need
Normative need
Comparative need
‘Felt need’ definition
Individual perceptions of deviations from normal health
‘Expressed need’ definition
Seeking help to overcome variation in normal health
‘Normative need’ definition
Professional expert defines intervention for expressed need e.g. vaccination
‘Comparative need’ definition
Comparison between severity, range of interventions and cost
Maslow’s hierarchy of needs
Physiological
Safety
Love/belonging
Esteem
Self-actualisation
Egalitarian resource allocation + pro/con
Provide all care that is necessary and required to everyone
+ equal for everyone
- economically restricted
Maximising resource allocation + pros/cons
Based solely on consequence
+ resources allocated to those likely to receive most benefit
- those with ‘less need’ will receive nothing
Libertarian resource allocation + pros/cons
Each individual responsible for own health
+ onus on patient, therefore may be more engaged
- not all diseases are self-inflicted
Maxwell’s 6 dimensions of quality
3 A’s, 3 E’s
Appropriateness / Effectiveness
Acceptability / Efficiency
Accessibility / Equity
Donabedian’s 3 step approach to quality
Structure
Process
Outcome
Examples of ‘structure’ in Donabedian’s 3 step approach to quality
Buildings e.g. wards
Facilities e.g. beds
Staff e.g. ratios to patients
Equipment e.g. new investment
Technology e.g. electronic notes
Examples of ‘process’ in Donabedian’s 3 step approach to quality
Guidelines + Protocols + Pathways of care = followed
Number of patients treated
User satisfaction surveys
Waiting times
Frequency of follow-up
Examples of ‘outcome’ in Donabedian’s 3 step approach to quality
Recovery
Morbidity rates
Mortality rates
Trends in preventable disease
Reduction in incidence in a population
Health behaviour aim
Behaviour aimed at preventing disease e.g. going for a run
Illness behaviour aim
Behaviour aimed at seeking remedy e.g. going to GP for a symptom
Sick role behaviour aim
Behaviour aimed at getting well e.g. taking antibitiotics
6 models of behaviour change
Theory of planned behaviours
Nudge theory
Health belief model
Motivational interviewing
Transtheoretical model
Financial incentives
Theory of planned behaviours model
intention is the greatest predictor of health behaviours
- Attitudes
- Subjective norms
- Perceived behaviour control
Advantages of theory of planned behaviours model
Can be applied to wide variety of health behaviours
Useful for predicting intention
Takes into account importance of social pressures
Disadvantages of theory of planned behaviours model
No temporal element, direction or causality
Doesn’t consider the complexity of human emotions
Assumes attitudes can be measured
Health belief model key 5 factors
Perceived susceptibility
Perceived severity
Health motivation
Perceived benefits
Perceived barriers
Other variables that could influence the health belief model
Demographic variables including age, gender and SE status
Psychological characteristics including personality, peer pressure
Advantages of the health belief model
Can be applied to wide variety of health behaviours
Cues to action are unique component
Longest standing model
Disadvantages of the health belief model
Other factors may influence the outcome
Doesn’t consider emotions
Doesn’t differentiate between first time and repeated behaviours
4 questions to consider when assessing medical negligence
Was there duty of care?
Was there a breach in that duty?
Was the patient harmed?
Was the harm due to the breach in care?
Twin pillars of medical negligence
Bolam rule (would a reasonable doctor do the same?)
Bolitho rule (would that be reasonable?)
Error definition
‘never events’
A serious largely preventable patient safety incident that should not occur if available, preventative measures have been implemented
Types of error (7)
Lack of skill
Over attachment (conducting tests to confirm what we expect to see)
Failure to consider the alternative
Mistriage
Ignorance
Inheriting thinking
Bravado
Variables of ‘self’ in the 3 bucket model of error
Level of knowledge
Level of skill
Level of expertise
Current capacity to do task
Variables of ‘context’ in the 3 bucket model of error
Equipment + devices
Physical environment
Workspace
Team + support
Organisation + managment
Variables of ‘task’ in the 3 bucket model of error
Errors
Task complexity
Novel task
Process
4 screening tests in UK
E.g:
Newborn (heel prick)
Breast cancer (mammography)
Cervical cancer (smear)
Bowel cancer (stool in the post)
Screening criteria: disease factors
Important
Pre-clinical phase
Natural history known
Early treatment better than late / effective treatment available
Screening criteria: test
Fit for purpose (sensitive, specific, cost-calculated)
Acceptable to the population
Facilities available
Simple, safe, precise and validated
Screening criteria: outcomes
Ongoing feasibility
Treatment available
Cost-benefit analysis
True positive
Test +ve
Dx +ve
False +ve
Test +ve
Dx -ve
False -ve
Test -ve
Dx +ve
True -ve
Test -ve
Dx -ve
Cross-sectional study definition
Snapshot data of those with and without disease to find associations at a single point in time
Cross-sectional study positives (2)
Quick and cheap
Few ethical issues
Large sample size
Cross-sectional study negatives (2)
Risk of recall bias and non-response
Cannot measure incidence
Risk of reverse causality
Case-control study definition
Retrospective observational study which looks at a certain exposure and compares similar participants with and without the disease
Case-control study advantages
Good for rare diseases e.g. cancer
Quicker than cohort or intervention as the outcome has already happened
Case-control study negatives
Can only show association (not causation)
Unreliable due to recall bias
Cohort study description
Longitudinal prospective study which takes a population of people recording their exposures and conditions they develop
Cohort study advantages
Can follow-up a group with a rare exposure e.g. natural disaster
Less risk of selection and recall bias
Good for common outcomes
Cohort study negatives
Takes a long time
Large amount lost to follow up (people dropping out)
Large sample size needed
Expensive
RCT description
Similar participants randomly controlled to intervention or control groups to study the effect of the intervention
GOLD STANDARD
RCT study positives
Can infer causality
Less risk of bias/confounders
RCT study negatives
Time consuming and expensive
Ethical issues can interfere
Bradford Hill criteria for causality (4)
Specificity (relationship specific to outcome of interest)
Strength of association
Dose response relationship
Temporality
Confounding factor definiton
Risk factor independently associated with the exposure and the outcome
Bias definition
A systematic error that results in a deviation from the true effect of an exposure of an outcome
Types of bias (SIP)
Selection
Information
Publication
4 types of information bias
Measurement bias (different equipment used to measure the outcome in the different groups)
Observer bias (not double blind)
Recall bias (past events incorrectly remembered)
Reporting bias (responder doesn’t tell the truth)
Sensitivity equation
it is able to pick it (true positives) up but it might not pick it all up (false negatives left behind)
Specificity equation
True negatives / True negatives + False positives
2 ethical frameworks that can be used to assess an ethical dilemma
Seedhouses’s ethical grid
Four quadrants approach
Four quadrants approach to an ethical dilemma
Medical indications (beneficence and non-mal)
Contextual features (justice)
Patient preferences (autonomy)
Quality of life (beneficence and non-mal)
Analogy: GP appointment - PC/PMH (medical indications), social history (contextual features), ICE (patient preferences), Management (QOL)
Seedhouse’s ethical grid 4 layers
Core rational
Deontological layer (beneficence and non-mal)
Consequential layer (increase of good)
External considerations
Who can provide consent for a child who lacks capacity
Consent from one parent is sufficient to administer treatment as long as it is in the best interest of the child
Public health definition
The science and art of preventing disease, prolonging life and improving health through organised efforts of society
3 perspectives of a health needs assessment
- Epidemiological
- Comparative
- Corporate
3 systems of resource allocation
- Egalitarian
- Maximising
- Libertarian
Primary prevention
Preventing disease from occurring in the first place e.g. vaccine
Secondary prevention
Early identification/Screening e.g. cancer screening
Tertiary prevention
Limit consequences/Treatment e.g. stroke rehab
Population approach to prevention
Shift the risk factor distribution curve e.g. dietary salt reduction through legislation to reduce blood pressure
High risk approach to prevention
Identify high risk individuals and treat them e.g. screening for BP and treating with anti-hypertensives
Prevention paradox
Benefit to the population often offers little impact to each participating individual e.g. most people don’t ever need a seatbelt but wearing a seatbelt saves thousands of lives
Pros of screening
Reproductive choice
Informed decision
Reassurance
More effective treatment
Cons of screening
Exposure of well individuals to distressing or harmful diagnostic tests e.g. colonoscopies
Detection and treatment of sub-clinical disease that would never have caused any problems
Over treatment
Difficult decisions
Anxiety or false reassurance
UK screening programmes (11)
3 in pregnancy (sickle cell and thalassaemia, infectious disease (HIV, Hep B and syphilis), and Down’s, Edward’s and Patau’s)
3 in newborn baby (NIPE, hearing, heel prick)
5 in young people and adults - BBC (bowel 60-74, breast 50-70, cervical 25-64), Diabetic eye screening (from age 12), Abdominal aortic aneurysm (over 65 men)
Wilson and Jungner Criteria for a screening test
- The condition: knowledge of the disease (important, understood, recognisable stages)
- The screening programme (ongoing, cost balance)
- The test (suitable test, accepted by public)
- The treatment (accepted treatment, enough facilities, agreed policies on who to treat)
Sensitivity definition
The ability of a test to correctly identify patients with a disease
Specificity definition
The ability of a test to correctly identify people without the disease
Positive predictive value definition
Out of the total positive screening test results, who was actually positive?
Negative predictive value definition
Out of the total negative screening test results, who was actually negative?
Analysing screening test (2 types of bias)
Length time bias
Lead time bias
Top of the hierarchy of evidence
Systematic reviews & meta analysis
Bottom of the hierarchy of evidence
Editorial reviews
Odds equation
Probability event occurs / probability event does not occur
Causes of association
Bias
Confounding factors
Chance
Reverse causality
True association
Epidemiology
Branch of medicine that deals with incidence, distribution and possible control of diseases
Incidence
Number of new cases over a certain time period
Prevalence
number at set point in time
Person-time definition
Measure of the actual ‘time at risk’ that all patients contributed to a study
Risk definition
The probability that an event will occur
Relative risk
Percentage of outcomes in one group/percentage of outcomes in another group
e.g. 1/3 women getting breast cancer vs 1/833 men
RR = 0.33/0.001 = 330 (women are 330 x more likely to get breast cancer than men)
Number needed to treat definition
The number you need to treat to prevent one bad outcome from happening
Factors that influence perceptions of risk (4)
Lack of personal experience with problem
Belief that it is preventable by personal action
Belief that if it has not happened by now, its not likely to
Belief that the problem is infrequent
Transition points (6)
Leaving school
Entering the workforce
Becoming a parent
Becoming unemployed
Retirement
Bereavement
Transtheoretical model stages of change
Principles of treating drug use
Reduce harm to user, friends and family
Improve health
Stabilise life
Reduce crime
Level of alcohol dependency factors (3)
Withdrawal symptoms
Tolerance
Narrowing of repertoire
Barriers to refugee health
Reluctance of GPs to register them
Illiteracy
Communication
Lack of permanent site
Mistrust of professionals
Malnutrition 2 groups
Under nutrition
Overweight, obesity
Triple = coexistence of undernutrition (stunting and wasting), micronutrient deficiencies (often termed hidden hunger), and overnutrition (overweight and obesity)
4 dimensions of food insecurity
Availability (affordability) of food
Access - economic
Utilisation
Stability
Need definition
The ability to benefit from an intervention
Need supply demand Venn diagram
Benefits of comparative health needs assessment
Quick
Inexpensive
Evaluation of health needs assessment (2 +, 2 -)
+ improved patient care
+ better use of resources
- data access
- conflicts of interest
Health equity audit
Helps services reduce health inequalities by using evidence to inform service planning and investment decisions
Health impact assessment
Systematically assesses the potential health impacts of programmes and policies to improve decision making and help to predict future positive and negative health impacts of other projects
Quaternary prevention
Prevent complications from over medicalising or over treatment of a condition
Primordial prevention
Prevents risk from developing
Public health interventions at population vs individual vs community level examples
Population: clean air act to reduce air pollution e.g. smoking ban
Individual: childhood immunisation schedule
Community: creating community spaces e.g. playgrounds
Prevalence of no disease
Everyone who does not have the disease out of the whole population tested i.e. are we testing for a disease that is actually rare? Is it worth testing for?
Length time bias example
Less aggressive cancers are diagnosed more on screening tests because a patient will survive longer to participate in screening
Lead time bias
A patient can appear to have survived longer from a disease because their disease was identified earlier
Absolute risk
Risk of developing a disease over a time period e.g. 1 in 3 women will develop breast cancer during their lifetime
Reverse causation
People believe X causes Y, but actually Y causes X
Odds ratio
How strongly an event is associated with exposure, commonly reported for case control studies
Odds of event in exposed group / odds of event in non-exposed group
Advantage of the epidemiological approach health needs assessment
Uses existing data e.g. from GPs
Provides data on disease incidence, mortality etc.
Can calculate services by trends over time
Selection bias
Systematic error in selection of study participants
1. Non-response
2. Loss to follow up
3. Differences in intervention group to control
Corporate health needs advantages
Based on the felt and expressed needs of the population in question
Recognises the detailed knowledge of those working with the population e.g. teachers, social workers
Comparative health needs assessment advantages
Quick and cheap if data is available
Indicates whether health or services provision is better or worse than comparable areas
