Public Health Flashcards
Define equity versus equality?
equity: what is fair and just
equality: having fair shares, may not always be equitable
What is horizontal versus vertical equity?
horizontal = equal treatment for equal need
vertical = unequal tx for unequal need eg poor area needs more services
Define the inverse care law
Availability of health care tends to vary inversely with need
What are the key determinants of health?
PROGRESS:
Place of residence
Race
Occupation
Gender
Religion
Education
Socio economic
Social capital
What are the 3 domains of public health practise?
- health improvement: societal interventions aimed at preventing disease, promoting health + reducing inequality
- health protection: measures to control infectious disease and environmental hazards
- improving services: delivery of safe, high quality services
What are Maxwell’s dimensions of the quality of health care?
3As, 3Es
Acceptability
Accessibility
Appropriateness
Effectiveness
Efficiency
Equity
What are the 3 steps of health care evaluation?
structure - what is there eg number of hospitals
process - what goes on eg how many patients seen
outcome eg number of deaths
Define health needs assessment
a systematic approach for reviewing health issues affecting a population
in order to enable agreed priorities and resource allocation
to improve health and reduce inequalities
What is need vs demand vs supply?
need = ability to benefit from an intervention
demand = what people ask for
supply = what is provided
What is health need vs health care need?
health need = ability to benefit from an intervention measured using mortality/morbidity
health care need = ability to benefit from health care
Define felt need
individual perceptions of variation from normal health
Define expressed need
individual seeks help to overcome variation in normal health (demand)
Define normative need
professional defines intervention for the expressed need
Define comparative need
comparison of severity, range of interventions and cost between two groups with similar characteristics
A health needs assessment is based on what 3 perspectives?
- epidemiological
- comparative
- corporate
What is considered in the epidemiological perspective of a health needs assessment?
size of problem
services available - prevention or tx
evidence base
What are the pros + cons of using the epidemiological perspective in a health needs assessment?
+ uses existing data
+ provides data on disease incidence/mortality/morbidity
- quality of data variable
- data collected may not be data required
- does not consider felt needs or opinions/experiences of people affected
What is the comparative perspective of a health needs assessment inform health need?
compares services/outcomes received by a population with others
eg spatial, social - age, gender, ethnicity, class
What may the comparative perspective of a health needs assessment include?
health status
service provision and utilisation
heath outcomes - mortality, morbidity, QoL, patient satisfaction
What are the pros + cons of the comparative perspective in a health needs assessment?
+ quick + cheap
+ indicates relative performance of health provision
- difficult to find comparable population
- data may not be available/high quality
What is the corporate perspective of a health needs assessment?
ask local population what their health needs are using focus groups/interviews etc
What are the pros + cons of the corporate perspective in a health needs assessment?
+ based on felt + expressed needs
+ recognises detailed knowledge/experience of those working within the populations
+ wide range of views
- difficult to distinguish need from demand
- groups may have vested interests
- may be influenced by political agendas
What 3 principles is resource allocation based on?
- egalitarian - provide all care that is necessary and required for everyone
- maximising - evaluate entirely in terms of consequences, is it beneficial?
- libertarian - each is responsible for their own health
What are the pros and cons of egalitarian resource allocation?
+ equal for everyone
- economically restricted
What are the pros and cons of maximising resource allocation?
+ allocated to those who it is most likely to benefit the most
- those with less need receive nothing
What are the pros and cons of libertarian resource allocation?
+ promotes patient engagement
- most disease not self inflicted
What is primary vs secondary vs tertiary prevention?
primary = preventing disease occurring g vaccine
secondary = early identification to alter disease course eg screening
tertiary = limit consequence of established disease
What is the population versus high risk approach to prevention?
population = delivered to everyone to lower the number of people at risk eg dietary salt reduction through legislation
high risk = identify individuals above chosen cut-off and treat eg screening for high BP and treat
Define the prevention paradox
A preventive measure which brings much benefit to the population often offers little to each participating individual eg seatbelts
Define screening
A process that sorts out apparently well people who probably have a disease from those who probably don’t
What is the Wilson Jungner criteria for screening?
INASEP
Important disease
Natural history of disease understood - known marker, recognisable early/latent stage
Acceptable to population - not too invasive
Simple, safe, precise test
Effective treatment - early vs late detection has better outcomes, accepted by population
Policy agreed on who to tx + facilities to treat them
Cost
Screening must be ongoing
What are the disadvantages of screening?
over detection of subclinical disease
harmful/distressing diagnostic tests following screening
preventive interventions may be harmful eg SEs of meds
Define sensitivity
ability to detect people with disease
= TP/total disease population (TP + FN)
What can a highly sensitive test indicate?
high SeNsitivity = SNout = rule out
disease has a trait which is almost always present + the test looks for this trait > if the trait isn’t present > disease unlikely > rule out
Define specificity
excluding those without disease correctly
= TN/TN + FP
What can a highly specific test indicate? But what is the caveat to this?
highly SPecific = SPin = rule in
helps rule a disease in when positive as the trait is rare in other diseases
HOWEVER a positive doesn’t = diseases because it doesn’t factor in prevalence of the disease
What is the consequence of low specificity?
high number of FP follow ups
Define positive predictive value
proportion of people who test +ve who actually have the disease
= TP/TP + FP
Define negative predictive value
proportion of people who test negative who don’t have the disease
= TN/FN + TN
What factor impacts predictive values but not sensitivity and specificity?
underlying prevalence
Define lead time bias
early identification doesn’t alter outcome but APPEARS to increases survival eg pt knows they have the disease for longer
Define length bias
slowly progressing diseases more likely to be caught in screening > makes it look like screening prolongs life when it is only catching slow growing types eg cancer
What are the 2 types of observational study?
descriptive > ecological, case reports
analytical > cohort, case control
both > cross sectional
What is an ecological study?
type of cross sectional study
carried out on the population, not individual
eg income, pollution, climate, diet
shows prevalence + association, not causation
What is a cross sectional study?
data collection from a population at a single point in time = prevalence study eg census
shows snapshot of populations current health data
not emerging new data
What are the pros and cons of a cross sectional study?
+ large sample size
+ data on prevalence of RF/disease
+ useful for PH planning
+ cheap, quick
- no time reference > risk of reverse causality (outcome caused the exposure) > cannot assume causality
- cannot distinguish between causal factors and factors that cause the disease to persist
- not useful for rare conditions
What is a cohort study?
longitudinal study on a group of individuals who share a common characteristic
RFs/tx eg one has intervention, one doesn’t
follows up over time to measure who gets disease
can be retro/prospective
What are the pros and cons of a cohort study?
+ can follow up rare/dangerous exposure that would be unethical in RCT
+ identification of RFs
+ accurate + detailed exposure assessment in a prospective study incl dose response
+ identify potential confounders prospectively
+ meet temporality criteria for causality
- long time, can be impractical
- large sample size required
- people dropout
- cost - active follow-up costly
What is a case control study?
looks for people with a disease, then looks back at exposure, to establish cause
What are the pros and cons of a case control study?
+ quick, cheap
+ good for looking at rare DISEASE
+ can study effect of multiple exposures on risk for a single disease
- difficulty finding similarly matched control participants
- prone to selection, information, observer and response bias
- not suitable for rare exposures
- not suitable for studying multiple outcomes for a single exposure
What are the 2 types of study?
- observational
- experimental
Name an experimental study type
RCT - participants randomised, one group receives tx, other acts as a control
What are the pros and cons of an RCT?
+ low risk of bias/confounding due to randomisation
+ can infer causality
- time consuming
- expensive
- still can be unreliable if sample not representative eg volunteer bias
What are the 5 stages of grief?
denial
anger
bargaining
depression
acceptance
What is adjustment disorder? Provide examples.
reaction to an event is maladaptive/not expected
- recovery too long - acceptance in grief pathway should be by 6m
- coping mechanisms extreme/harmful
-continuing impact on relationships/school/work - self-harm/suicide
What is the toxic triangle for child abuse?
parents MH
alcohol + drug abuse
domestic abuse
What risk assessment is used do assess domestic abuse?
DASH
low = serious harm unlikely
medium = serious harm unlikely without change in circumstance > give helpline contact details
high = risk of imminent harm > refer to MARC/IDVAS
Define public health
state of complete physical, mental + social wellbeing
What is the equation for odds?
probability/1-probability
Define odds ratio
measure of association between exposure + outcome
ie odds something will happen given a particular exposure compared to odds it will happen without that exposure
= odds in cases/odds in controls
Define bias
systematic error that results in deviation from the true effect of an exposure on an outcome
What is selection bias?
systematic differences between characteristics of individuals sampled and the population from which the sample is taken
OR between the comparison groups within the study
What is information bias?
systematic error in measurement/classification of exposure or outcome
Name some sources of information bias
MORRP
Measurement bias - different equipment measure things differently
Observer bias - observer’s expectations influence reporting
Recall bias - past events not recalled correctly
Reporting bias - respondent doesn’t report truth due to shame/judgement
Publication bias - trials with neg results less likely to be published
What are confounders?
factors other than those being studied which influence the outcome
must be independently a/w exposure and outcome but must not lie on the causal pathway between the two
eg grey hair + back pain > CF = age
What are the possible causes for an association found in a study?
bias
chance
confounding
reverse causality
true association
What are the Bradford Hill criteria for causality?
STDS R CrAP
Strength of association - amount of RR
Temporality - does exposure precede outcome in time?
Dose response - the higher the risk of exposure the higher the risk of disease
Specificity - the relationship is specific to the outcome of interest
Reversibility - removal of exposure reduces risk of disease
Consistency - similar results from different researchers using various study designs
Coherence - coherence with previous knowledge/biological background
Analogy - similarity with other established cause-effect relationships
Plausibility - existence of reasonable mechanisms for the cause and effect
Define epidemiology?
study of the frequency, determinants + distribution of diseases + health related states in populations in order to prevent/control disease
Define incidence
number of new cases/time
incidence rate = new cases in a time period/total person time at risk in time period
Define prevalence
number of people with a disease at a certain point in time
Define person time
measure of time at risk ie time from entry to study until disease onset, loss to follow up or end of study
used to calculate incidence rate
Define absolute risk
likelihood of an event happening under specific conditions
needed to contextualise RR
has units
eg there is a baseline absolute risk of developing bowel cancer of 5.6% + RR of 1% if you are a meat eater > absolute risk is 6.6% for meat-eaters
Define relative risk
ratio of risk of disease (incidence) in the exposed to the risk in the unexposed
no units
Define attributable risk
incidence in exposed minus incidence in unexposed
What is the number needed to save 1 person equation?
1/attributable risk of exposure
What is the number needed to treat equation?
1/absolute risk reduction
What is positive versus negative conditions in addiction?
positive = addiction increases desire to use drug
negative = don’t quit due to unpleasant withdrawal
What are the methods of opiate detoxification?
transition to abstinence = methadone (free, taken orally so no injection related issues)
buprenorphine - alternative, safer than methadone as is a partial agonist
naltrexone - opioid antagonist used to prevent relapse
Who is more likely to do opiate detoxification effectively?
young users
less time addicted
low level of drug use
What is the mode of action of cocaine/crack?
blocks reuptake of serotonin + dopamine at synapses > intense pleasure
depletion > anxiety, panic, adrenaline secretion, wired
What is health versus illness versus sick role behaviour?
health behaviour = aimed to prevent a disease eg healthy eating
illness behaviour = activity aimed at defining the illness to seek a remedy eg going to the dr
sick role behaviour = action taken aimed at getting well eg taking meds
What is theory of planned bheaviour?
best predictor of behaviour is intention
eg personal attitude, the subjective norm (friends/family), perceived behavioural control
What is the key criticism of theory of planned behaviour?
lack of time element > lack of direction/causality
What is unrealistic optimism theory?
people engage in health risky behaviours due to inaccurate perception of risk and susceptibility
What is the transtheoretical model?
5 stages of change:
1. pre-contemplation
2. contemplation
3. preparation
4. action
5. maintenance
What is motivational interviewing?
attempts initiating behaviour change by resolving ambivalence
Define nudge theory
nudge the environment to make best option the easiest eg putting fruit next to checkouts
What is the health belief model?
chance of action being carried out is a/w person’s belief that it will work + cues to action
What factors are involved in the health belief model?
perceived benefit, severity, susceptibility + barriers
health motivation
What are the 5 domains of exclusion in older people?
material resources
civic activities
basic services
neighbourhood
social relationships
What are the steps in the management of a disease outbreak?
- clarify problem - make a dx
- outbreak? - 2+ related cases
- gain help
- call outbreak meeting
- identify cause
What are the 5 stages of Maslow’s hierachy of needs?
- physiological: air, water, food
- safety: security of body, resources
- love belonging: friendship, family, intimacy
- esteem: confidence, achievement, respect
- self-actualisation: morality, creativity, problem solving
What are the common causes of homelessness?
relationship breakdown
DA
fight with parent
bereavement
What is an asylum seeker versus refugee?
AS: someone who is applying for refugee status
refugee: someone who has been granted asylum status, usually lasts 5yrs
What does an asylum seeker receive in terms of support?
vouchers to live off
NASS support package
access to NHS
not allowed to work
no choice where they go
Define humanitarian protection?
failed to get asylum but serious threat of returning means they can stay for 3yrs
What antimicrobial resistance are asylum seekers/refugees more likely to have?
ESBL/extended spectrum B-lactamase producer
= resistant to ALL pencillin + cephalosporins
= need broad-spec
What are the 5 key articles in the human rights act 1998?
right to:
2 - life
3 - freedom from inhuman/degrading tx
8 - respect for privacy + family life
12 - marry and found a family
14 - freedom from discrimination
What are the causes of error in our own work?
sloth error - laziness, not checking things
skill based error
fixation/loss of perspective
error of commission
error of omission
communication breakdown
system failure
human factors eg bravado/timidity
judgement failure
neglect
poor performance
misconduct
What 4 things is error classification based on?
intention?
action?
outcome?
context?
What are tools of risk assessment?
incident reporting
complaints/claims
audits
external accreditation
active measurement
What are strategies to reduce error in our work?
team training
checklists
simplification and standardisation of clinical practise
What are the 4 parts of determining negligence?
- was there a duty of care?
- was there a breach in duty?
- was the pt harmed?
- was the harm due to the breach in care?
What are the 2 key negligence cases and their teachings?
bolam - would a group of reasonable drs do the same?
bolitho - would that be reasonable?
Define never events
serious large preventable patient safety incidents that should not occur if available preventable measures have been implemented
What is the personal versus systems approach when invetigating never events?
personal: holding 1 person responsible
systems: identifying there are latent errors in the system, latent + active causes come together to cause error = eliminates blame culture
What are the 6 key GMC duties of a dr?
- make the care of your patient your first concern
- protect and promote the health of the public
- provide good standard of practise and care
- treat patients as individuals and respect their dignity
- work in partnership with patients
- be honest and open and act with integrity
What is the medical model of disability?
is housebound, confined to a wheelchair, can’t walk/see/hear, needs help and carers etc > the problem is the disabled person
What is the social model of disability?
badly designed buildings, no ramps/lifts, few sign language interpreters, discrimination, inaccessible transport, isolated families, poor job prospects > the problem is the disabling world
Define negligence
breach of duty of care which results in damage
Define duty of candour
duty of dr to be open, honest and transparent > disclose errors
What is the swiss cheese model of negligence?
an organisations defences against failure are modelled as a series of barriers (slices of cheese)
holes in the slices = weakness in individual parts of the system > vary in size and position across the slices
system produces failure when a hole in each slice momentarily aligns and hazards pass through the holes (trajectory accident opportunity)
What is ethnocentrism?
tendency to value other groups according to the values/standards of one’s own culture group
especially with the conviction that one’s own culture group is superior to others
What is rationing?
refusing resources based on lack of affordability rather than clinical inaffectiveness
What may perception of risk be influenced by?
lack of personal experience with problem
belief if it hasn’t happened now, it is not likely to
belief that the problem is infrequent, may be linked to age etc
What are some criticisms of the health beliefs model?
alternative factors may affect health behaviours eg outcome expectancy, self-efficacy (person’s belief in their ability to carry out preventative behaviour)
does not consider influence of emotions on behaviour
doesn’t differentiate between 1st time and repeat behaviour
cutes to action often missing
What can help bridge the huge gap between intention and actual behaviour?
perceived control - think about the success of drug/action
anticipated regret - reflect on unwell they were/how they felt
preparatory actions - break down tasks into sub-goals
implementation intentions - what-if plans
relevance to self
What are the disadvantages of bridging methods between intention and actual behaviour?
patient’s emotions not taken into account
doesn’t tell us how attitudes/intentions/perceived behavioural control interact
assumes that attitudes/subjective norms/PBC can be measured
relies on self-reported behaviour
What are some important transition points in life to consider?
leaving school
entering workforce
becoming a parent
becoming unemployed
retirement
bereavement
What are the 4 types of leader?
inspirational
transactional - promotes compliance with reward and punishment
laissez faire - delegates, hands off approach, allows team members to make decisions for themselves
transformational - inclusive leadership distributes throughout all levels of organisation
WHat can decrease prevalence of a disease?
new tx
What factors influence incidence of a disease?
NOT affected by changes in prognosis
only changes in determinants of the disease
Does sample size affect bias?
no
Which methods can be used to reduce bias?
statistical methods cannot adjust for bias
random selection/allocation can reduce bias
In which studies is reducing selection bias most important in?
case-control - where cases and controls should only differ on outcome and exposure
problem because characteristics that influence the selection of participants may also affect the outcome of interest
Which type of participant selection has the highest selection bias?
people to volunteer = self-selected
likely to differ from general population > health awareness/education
What are the 2 most common confounding factors?
age
socioeconomic status
How can confounders be reduced?
randomisation
restriction - limits study to people who are similar in relation to confounder
matching - selects comparison groups to have same distribution of potential confounders
What is ecological fallacy?
mismatch that arises from trying to draw conclusions about individual level epidemiological associations from a group-level study
eg assuming every med student is good at maths because the average med student is
not possible to make causal inferences
What is a prospective vs retrospective cohort study?
prospective: start now and follow up, events not taken place yet
retrospective: uses existing data on exposure and outcomes
What bias may be present in a cohort study?
loss to follow up (selection bias - lose exposure group more/less than other group)
non-participation (selection)
classification of outcome/exposure (observer)
Why are double blinded RCTs the best?
avoids measurement/reporting/analytical bias
What bias can occur if an RCT is not blinded?
ascertainment bias > participants knows if they are receiving intervention/placebo their behaviour during the trial may be affected
observed bias > can occur if person assessing the outcome is aware of the allocation
What is opportunistic versus systematic screening?
opportunistic - when pt visits a HCP and is offered screening unrelated to the reason for their visit
systematic - organised health programmes
What does a low sensitivity mean?
identify many with the condition as not having the condition
Which types of disease is a high sensitivity essential for?
infectious
to reduce number of false negatives that could result in continued transmission
What does a low specificity mean?
lots of false positives
Does a screening programme need to prioritise high sensitivity or specificity?
specificity
subsequent dx tests are very expensive/carry risks, to avoid unnecessary procedures
Why is it difficult to measure the effectiveness of screening programmes?
selection bias - participants often differ from those who don’t eg fhx breast ca more likely to go to mammogram
lead-time bias - identifies an outcome earlier that it would otherwise have been but has no effect on outcome/prognosis
length-time bias - outcomes that take longer to develop to a stage where they threaten health eg slow growing breast ca tumour more likely to be detected by screening prior to sx than fast growing but are less aggressive with better prognosis = over-estimate screening success
What is seedhouse’s ethical grid? What 4 layers does it contain?
tool used by HCPs to consider possible actions to take when faced with a difficult situation
What 4 layers does Seedhouse’s ethical grid contain? Give examples of each
- core rationale eg respect people equally, respect + create autonomy, serve needs first
- deontological layer eg keep promises, tell the truth, do most positive good, minimise harm
- consequential layer eg most beneficial outcome for self, the individual, a particular group and society
- external considerations eg risk, codes of practise, law, wishes of others, resources available etc
