Public Health Flashcards
Equity vs Equality
Equity - Giving people what they need to achieve equal outcomes
Equality - Giving everyone the same rights, opportunities and resources
Horizontal vs vertical equity
Horizontal - Providing equal treatment for people with the same health needs. E.g. 2 towns with similar rates of asthma getting equal access to treatment and resources
Vertical - Different levels of care based on different needs. E.g. patients with more critical needs prioritised over minor illnesses
What are some determinants of health
PROGRESS
Place of residence
Race
Occupation
Gender
Religion
Education
Socio-economic
Social capital
What are 2 methods used to assess quality of healthcare
Maxwells dimensions of the quality of healthcare (3As, 3Es)
Donabedian’s framework of health service evaluation (structure, process, outcome)
Explain Maxwells dimensions of the quality of healthcare
(3As, 3Es)
- Acceptability
- Accessibility
- Appropriateness
- Effectiveness
- Efficiency
- Equity
Donabedian’s framework of health service evaluation
(structure, process, outcome)
S - What is the service? (e.g. number of hospitals)
P - How does the service work/what goes on? (e.g. how many patients seen)
O - Outcome (e.g. Number of deaths)
Outcomes (5 Ds):
- Death
- Disease
- Disability
- Discomfort
- Dissatisfaction
What are some issues with assessing health outcomes
- Link between service and outcome can be difficult to confirm
- Time lag between service and outcome may be long
- Large sample sizes needed
- Data problems (CART - Completeness, Accuracy, Relevance, Timeliness)
What is a Health Needs Assessment
Systematic method for reviewing the health needs facing a population, leading to agreed priorities and resource allocation that will improve health and reduce inequalities
What are the types of health care need
Felt Need - Individual perception of variation from normal health (patient feels ill)
Expressed need - Individual seeks help to overcome variation (patient goes to doc)
Normative need - Professional defines intervention for expressed need (doctor says what they need)
Comparative need - Comparison between severity, range of interventions and cost
What are 3 perspectives of a health needs assessment
Epidemiological - Looks at evidence base (incidence/prevalence, availability of services, cost effectiveness etc)
Comparative - Compares services and outcomes received by a population with others (can be spacial or social - areas or ages for example)
Corporate - Asking local population what their needs are (focus groups, public meetings, interviews etc)
Give a pro and con for each type of health needs assessment perspective
Epidemiological
- Pro: Uses existing data and provides evidence of incidence/morbidity/mortality
- Con: Quality of data variable, Data collected may not be data required, Does not consider felt needs/opinions
Comparative
- Pro: Quick and cheap if data available. Allows comparison for service effectiveness
- Con: Difficult to find comparable populations, may not be available or high quality
Corporate
- Pro: Based on felt and expressed needs of population. Recognises knowledge and experience of those within the population
- Con: Difficult establishing need from demand. Groups may have vested interests or political agendas
What are 3 resource allocation methods
Egalitarian - Provide ALL necessary and required care to everyone. (Equal, but expensive)
Maximising - Act solely evaluated by its consequence (Resources allocated to those most likely to benefit, those who dont make cut get nothing)
Libertarian - Each individual responsible for their own health (Promotes engagement in own healthcare, most diseases not self inflicted)
What are the 3 types of prevention
Primary - Prevention of condition before it occurs (e.g. vaccine)
Secondary - Early identification to alter disease course (e.g. screening)
Tertiary - Limit consequences of established disease (e.g. preventing worsening of renal function in CKD)
What are 2 approaches to disease prevention and what is a prevention paradox
Population - Prevention approach delivered to everyone to shift risk factor distribution curve (e.g. dietary salt reduction through legislation)
High risk - Identify individuals above a chosen cut off and treat (e.g. Blood pressure screening)
A preventative measure which brings benefit to the population often offers little impact to each participating individual (E.g. if everyone wore seat belt, for every life saved, 400 would never benefit from it)
What is Need, Demand and Supply
Need - Ability to benefit from intervention
Demand - What people ask for
Supply - What is provided
What is the purpose of screening
The purpose of screening is to identify apparently well individuals who have (or are at risk of developing) a particular disease so that you can have a real impact on the outcome.
What are some downsides to screening
Exposure of well individuals to harmful or distressing diagnostic tests
Detection and treatment of sub-clinical disease that would never cause problems
Preventative interventions that may cause harm to individual or population
Anxiety or false assurances
What screening programmes exist in pregnancy
- Infectious diseases in Pregnancy Screening Programme (hep B, syphilis, HIV)
- Sickle Cell and Thalassaemia Screening
- Fetal Anomaly Screening Programme (Down’s syndrome, Edwards’ syndrome and
Patau’s syndrome)
What screening programmes exist in newborns
- Newborn and Infant Physical Examination (hearts, eyes, hips, testes)
- Newborn Hearing Screening Programme (permenant childhood hearing impairment - Done via Otoacoustic Emissions testing and Auditory Brainstem Response as follow up if failed.)
- Newborn Blood Spot Screening Programme (sickle cell disease, CF, congenital
hypothyroidism + 6 inherited metabolic disease)
What is the criteria for disease screening
Wilson and Jungner
Condition
- Important, natural history understood, disease should have a latent, detectable stage
Program
- Ongoing, cost effective
Test
- Simple, safe, precise, validated
- Distribution of values must be known with clear cut off
- Acceptable to population (not too invasive)
- Agreed policy on further investigation of individuals with positive result and on choices available to them
Treatment
- Effective treatment or intervention for patients identified through early detection, with evidence of better outcomes compared to late treatment
- Agreed policy on who to treat
“In Exam Season, NAP”
- Important disease
- Effective treatmtent available
- Simple and Safe to test for
- Natural history known
- Acceptable to population (not invasive)
- Policy on who/how to treat agreed
What is sensitivity, specificity, positive predictive value and negative predictive value
Sensitivity - Proportion of those with condition that are correctly identified with positive test
PPV - Those with positive test, who actually had the condition
Specificity - Proportion of those without disease correctly excluded
NPV - Those with negative test, who actually dont have the disease
Lead time vs length time bias
Lead time: Early identification doesnt alter outcome, but appears to increase survival as disease was identified earlier than normal.
Length time: Disease that progresses slowly is more likely to be picked up in screening, making it appear that screening lengthens life, even though slow progressing disease always wouldve killed that late, as opposed to rapid progressing.
E.g. Lead time: Diagnosed earlier but person still dies same time from symptoms onset
Length time: E.g. Slow-growing disease, or disease with long latent period. Screening more likely to detect less severe disease, falsely suggesting improved outcome
Define these biases:
- Selection
- Information
- Allocation
- Publication
Selection is an error in
- Selection of study participants, allocation of participants to different study groups, causing sample to not be representative of general population
- Including/excluding groups e.g. more health conscious people, or selectively choosing based on sex,age,etc no longer reflecting broader population.
Information bias is
- Error in observer’s recall and reporting. Paricipant, instrument wrongly calibrated. Error in data collection/measurement
Allocation bias is
- Non random assignment of participants to different treatment groups in a study. Can lead to differences between groups confounding the results
- E.g. younger healthier people in one and older and sicker people in another. Younger/healthier always gonna look better
Publication
- When positive or significant results are more likely to be published than not.
- Can lead to overestimations of safety/efficacy of interventions
What is a case control study with pros and cons
Retrospective, observational study looking at cause of disease. Compares similar participants with disease to controls without
Pros: Good for rare outcomes, quicker than cohort or intervention studies, investigate multiple exposures
Cons: Difficulties finding controls to match with case, prone to selection and information bias
What is a cross sectional study
Retrospective, observational
Collects data form population at a specific point in time (“snapshot”). Prevalence of risk factors and disease itself
Pro:
- Relatively quick and cheap
- Provide data on prevalence at point in time
- Good for surveillance and PH planning
Cons:
- Risk of reverse causality (Did exposure or outcome come first?)
- Cannot measure incidence
- Recall and response bias risk (may miss quick recoveries)
What is a cohort study
Prospective longitudinal study looking at separate cohorts with different treatments or exposures
Pros:
- Can follow up a group with rare exposure
- Good for common and multiple outcomes
- Less risk of selection and recall bias
Cons
- Takes a long time
- Large sample size, expensive, time consuming
- People drop out
What is a RCT
Prospective study, all participants assigned a random exposure or control intervention
Pros
- Low risk of bias and confounding
- Can infer causality
Cons:
- Time consuming, expensive
- Drop outs
- Inclusion criteria may exclude populations
What is an ecological study
A study that looks at the prevalence of a disease over time in a population rather than individuals
What are odds
Odds are used to look at binary outcomes e.g. if a disease occurs, or if it doesn’t. To work out divide the probability of it occurring by the probability of it not occurring.
[Probability the event occurs (p)] / [Probability it doesn’t (1-p)]
What is an odds ratio, and how should they be interpreted
Comparing the odds of an outcome occurring between 2 groups. E.g. a group with a treatment, and a control group.
Odds ratio = Odds of an event (Group/Condition A) / Odds of an event (Group/Condition B - (Tends to be control))
Ratio = 1
- No change in odds of outcome in either group. Change in condition did not affect odds.
Ratio > 1
- Numerator>denominator. Odds of event happening are higher in numerator than denominator. Often denotes a risk factor.
Ratio < 1
- Denominator>numerator. Odds lower for condition in the numerator. Often protective factor or treatment
Explain these types of information biases:
- Measurement
- Observer
- Recall
- Reporting
Measurement - Different equipment measuring differently
Observer - Observers expectations influencing reporting
Recall - Past events not recalled correctly
Reporting - Not telling truth due to shame/judgement
What is confounding
A situation where a factor is associated with the exposure of interest and independently influences outcome, but does not lie on causal pathway.
E.g. Lack of exercise causes weight gain, but many confounding variables also affect weight gain.
What is the criteria for causality
Bradford Hill - 9 criteria
- Strength - of association
- Dose-response - higher exposure=higher incidence?
- Consistency - Similar results in other studies/populations
- Temporality - Does exposure precede outcome?
- Reversibility - Does reducing exposure reduce risk?
- Biological plausability
- Coherence - Logical consistency with other info
- Analogy - Similarity with other cause-effect relationships
- Specificity - Relationship specific to the outcome of interest. E.g. helmets reduced head injuries, as opposed to accidents going down in general.
What is reverse causality
E.g. Did stress increase HTN or did increased HTN cause stress.
Define epidemiology, incidence, prevalence and person time
● Epidemiology: The study of the frequency, determinants and distribution of diseases and health related states in populations in order to prevent and control disease
● Incidence: Number of new cases over a certain time period
● Prevalence: The number of people with a disease at a certain point in time
● Person time: Measure of time at risk for all the patients in the study- therefore if 1,000 patients were studied for 2.5 years, the study would have looked at 2,500 person years
Define relative risk, absolute risk, and number needed to treat
Relative risk - Risk among exposed group divided by risk in unexposed group - doesn’t take into account baseline risk (e.g. new drug reduces incidence by 50%, may only be from 2 to 1)
Absolute (or attributable) risk - Subtract risk from control group from the exposed group, giving you the excess risk caused by the exposure (e.g. new drug reduces incidence 2 in 1000, down to 1 in 1000, so AR is 1 in 1000)
Number needed to treat - Number of patients to treat for one to benefit. 1/absolute risk. (E.g. AR is 1 in 1000, 1/(1/1000) = 1000 treated to save 1)
What are health behaviours
Health behaviour - Behaviour aimed at preventing disease e.g. eating healthy
Illness behaviour - Behaviour aiming to seek remedy e.g. going doctors
Sick role behaviour - Behaviour aimed at getting well e.g. taking tablets and resting
What 4 factors are perceptions of risk influenced by
- Lack of personal experience with problem
- Belief that it is preventable by personal action
- Belief that if it hasn’t happened by now, its not likely to
- Belief that the problem is infrequent
What are transition points
Points at which interventions are thought to be more effective
- Leaving school
- Entering workforce
- Becoming a parent
- Becoming unemployed
- Retirement and bereavement
What are some models of behaviour change
- Health belief model (HBM)
- Theory of Planned Behaviour (TPB)
- Stages of change /transtheoretical model (TTM)
- Social norms theory
- Motivational interviewing
- Social marketing
- Nudging (choice architecture)
- Financial incentives
What is the Health Belief Model
Individuals likely to change behaviour if they:
- Believe they are susceptible to condition
- Believe in serious consequences
- Believe action reduces susceptibility
- Believe benefits of taking action outweigh the costs
According to the Theory of Planned Behaviour, what 3 factors determine an individual’s health behaviour?
- Their attitude to the behaviour
- The subjective/social norm
- Their own perceived behavioural control
What are the 6 steps of the States of Change (Transtheoretical) Model?
- Precontemplation - No intention of changing the behaviour
- Contemplation - Aware of the problem but no commitment to action
- Preparation - Intent on taking action to address problem
- Action - Active modification of behaviour
- Maintenance - Sustained change, new behaviour starts to replace old
- Relapse - Fall back into old patterns
What does heroine act on and what does it do to the patient. What are some side effects
Acts on opiate receptors
Causes euphoria, miosis, drowsiness
Dpeendance, bad withdrawals, nausea, itching, sweating, constipation, respiratory depression
What drug is used for an opiate detox
Methadone
Naltrexone or buprenorphine are also used
What is crack cocaine and how does withdrawal present
Oral/snorting/IV/smoking
Blocks reuptake of serotonin - intense pleasurable sensation
Depletion at secretory neurons - anxiety, panic, adrenaline, wired. Leads to depression, panic, paranoia
What is Maslows hierarchy of needs
Self fulfilment:
- Self actualisation: Achieving full potential, including creative activities
Psychological
- Esteem: prestige/ accomplishment
- Belongingness/love: Intimate relationships, friends
Basic needs:
- Safety/security
- Physiological: food, water, warmth, rest
Works from bottom up. In order to fulfil self actualisation, basic necessities need to be fulfilled
What is used for Alcohol overuse assessment
CAGE questions
AUDIT - If score >15, refer for specialist support
Units: Volume (L) x %ABV = Units
How can alcohol dependency be gauged
- Withdrawals
- Cravings
- Drinking despite negative consequences on physical, mental, social/work life
- Tolerance - This is said to occur when the individual has to drink larger amount of alcohol to obtain similar effect
- Primacy (put drinking before other activities)
- Loss of control
Asylum seeker vs refugee
AS if seeking refugee status
R once granted, usually for 5 years
What do asylum seekers receive
- Vouchers to live off (restricted)
- NASS support package
- Access to NHS
- Not allowed to work, no control over location
What are some barriers to life for refugees
- Reluctance of GPs to register them
- Illiteracy
- Communication
- Lack of permanent site
- Mistrust of professionals
Health problems for refugees
Health problems for
refugees:
Injury/illness from war/ travelling
Communicable disease
Lack of health screening and immunisation
Malnutrition
Untreated chronic disease
Mental illness
Define malnutrition
Deficiencies, excesses, imbalances in a person’s intake of energy and/or nutrients. 2 broad groups:
- Undernutrition - Stunting (low height for age), wasting (low weight for height), micronutrient deficiencies (vitamins, minerals)
- Overweight, obesity and diet related non communicable diseases (heart disease, stroke, diabetes, cancer)
Four dimensions of food insecurity
- Availability
- Access - economic/physical
- Utilisation - Opportunity to prepare food
- Stability of 3 dimensions over time.
Types of error:
● Sloth error: being lazy, not bothering to check results/information for accuracy.
● Lack of skill: lack of appropriate skills or teaching in practice
● Communication breakdown: unclear instructions or plans and not
listening to others
● System failure: machine/equipment stopped working
● Human factors: bravado (working beyond means), timidity (not working to competence)
● Judgement failure
● Neglect
● Poor performance
● Misconduct
What should be taken into account when classifying the severity of an error
- Intention
- Action
- Outcome
- Context
What are the 4 components to consider in regards to a negligence error
- Was there a duty of care?
- Was there a breach in that duty?
- Was the patient harmed?
- Was the harm due to the breach in care?
What rules are questioned in the case of negligence
Bolam rule: Would a reasonable doctor do the same
Bolitho rule: Would that be reasonable?
What is a never event
Never event: Serious, largely preventable patient safety incidents, should not occur if the available preventative measures have been implemented
Why is a systems approach preferred to a person approach
Person approach - hold one person accountable
Systems approach - Identify there are latent errors in the system
Why is this good: systems approach
eliminates blame culture.
What is the swiss cheese model of error
When an error occurs due to a multiple failed or absence defences against errors
Holes line up, allowing the error to occur
What is the bucket model of error
The bucket model of error in healthcare categorizes mistakes into three “buckets”:
Knowledge Errors:
- Gaps in clinical knowledge or expertise.
Rules Errors:
- Failures to follow established protocols or guidelines.
Action Errors:
- Mistakes in performing tasks correctly, even when knowledge and rules are clear.
This model helps identify and address multiple sources of error, emphasizing a systems-based approach to improve patient safety by reducing individual blame and focusing on comprehensive safety measures.
What is duty of candour
Every healthcare professional must be open and honest with patients when
something that goes wrong with their treatment causes, or has the potential to
cause, harm or distress.
