Public Health Flashcards
Define Public Health
The science and art of preventing disease prolonging life and improving health through organised efforts of society
Define equity
Define equality
Define horizontal equity
Define vertical equity
equity - give people what they need to achieve equal outcomes
equality - give everyone the same rights opportunities and resources
horizontal equity - equal treatment for people with equal health care needs
vertical equity - unequal treatment to unequal health care needs
define inverse care law
availability of health care tends to vary inversely with its need
Determinants of Health
PROGRESS
P-PLACE OF RESIDENCE
R- RACE
O-OCCUPATION
G-GENDER
R-RELIGION
E-EDUCATION
S-SOCIOECONOMIC
S-SOCIAL CAPITAL
3 domains of public health practise
health improvement - societal interventions aimed at preventing disease, promoting health and reducing inequalities
health protection - measures to control infectious disease and environmental hazards
improving services - organisation and delivery of safe high quality services
in assessing quality of healthcare there is a framework what is it called?
explain it?
then it is important to see structure, process and outcome - what does this mean
maxwells dimensions of quality of healthcare
3 a’s and 3 e’s
acceptability
accessibility
appropriateness
effectiveness
efficiency
equity
structure- what is there? no. of hospitals
process - what goes on? - how many pts seen?
outcome: no. of deaths for ex
health needs assessment involves
give examples?
need - ability to benefit from an intervention
demand - what people ask for
supply - whats provided
eg: abx for mild infection is supplied and demanded but not deeded. routine vaccinations are needed and supplied but not demanded.
4 types of need
felt need - individual perceptions of variation from normal health -pt feels unwell
normative need - proffesional defines intervention for expressed need - then dr says what they need
expressed need - pt seeks help to overcome variation in normal health - pt goes to dr
comparitive need - comparison between severity, range of interventions and cost
when doing a health needs assessment you can look at epidemiological, comparative or corporate perspective.
if i am looking at epidemiological perspective, tell me what it does, where it gets info from and the pros and cons?
look at:;
- size of pop - incidence/prevalence
- services available: prevention/tx/care
- evidence base: effectiveness/cost effectiveness
sources: disease registry, admissions, gp databases
good:
- uses existing data
-provides data on disease incidence/mortality/morbidity
bad:
- quality of data variable
-data collected might not be data required
-doesnt consider felt needs/opinions of pts
when doing a health needs assessment you can look at epidemiological, comparative or corporate perspective.
if i am looking at comparitive perspective, tell me what it does, where it gets info from and the pros and cons?
compares services/outcomes recieved by a population with others
- compare diff areas or pt of diff ages
look at:
- health status
-service provision
-outcomes
good:
- quick and cheap if data available
- shows if services are better or worse than compared group
bad:
- can be difficult to find comparable population
-data might not be available/high quality
when doing a health needs assessment you can look at epidemiological, comparative or corporate perspective.
if i am looking at corporate perspective, tell me what it does, where it gets info from and the pros and cons?
ask local pop what their health needs are
use focus groups, interviews, public meeting
wide variety of stakeholders
good:
- based on felt and expressed need
- wide range of views takes into account
- recognises detailed knowledge and experience of those working with population
bad:
- can be difficult to distinguish need from demand
- groups might have vested interests
-may have political agendas
3 beliefs to resource allocation methods!! and explain
1 good and 1 bad for each
egalitarian
maximising
libertarian
egalitarian: provide all care necessary and required for everyone
good: - equal
bad: too expensive
maximising: - act is evaluated solely in terms of its consequences
good: resources allocated to those who most likely to benefit from it
bad - those who dont make the cut get nothing
libertarian - each are responsible for their own health
- good: promotes positive engagement
bad: most diseases are not self inflicted
explain primary secondary and tertiary prevention
primary
- preventing disease from occuring in first place - eg vaccine
secondary:
- early identification of disease to alter disease course eg : screening
tertiary:
- limit consequences of established disease eg: limit consequences of established disease eg: prevent worsening renal function in ckd
3 approaches to prevention
population approach
high risk approach
prevention paradox
population - prevention approach delivered to everyone to shift the risk factor distribution curve: dietary salt reductions through legislation
high risk approach: identify individuals above a chosen cut off and treat them eg : screening people for high bp and tx them
prevention paradox: preventative measure which brings much benefit to population often offers little impact to each participating individuals
Purpose of screening
disadvantages
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 .
- exposure of well individuals to distressing or harmful diagnostic tests
-detection and treatment of sub-clinical disease that would never cause any problems
-preventive interventions that may cause harm to the individual or population - incorrect results
-anxiety or false reassurance
over tx/tx risks
benefits of screening
reproductive choice
worthwhile use of resources
informed decision
reassurance
more effective tx
better future health
uk 3 screening programme examples in pregnancy
infectious diseases in pregnancy screening programme - hep b, syphillis, hiv
sickle cell and thalaseemia screening
fetal anomaly screening programme - downs, edwards, pataus
3 uk screening programmes in newborn babies
newborn and infant physical exam - hearts, eyes, hip, testes
newborn hearing screening programme - permanent childhood hearing impairement
newborn blood spot screening programme - sickle cell, cf, congenital hypothyroidism + 6 inherited metabolic disease
define sensitivity and specificity?
sensitivity: proportion of those with disease who are correctly idenitified - does the test pick up the disease
specificity - proportion of people without the disease who are correctly excluded by screening test: does the test identify people who dont have the disease
in terms of specificity and sensitivity explain what a positive and negative predictive value would mean?
positive: proportion of people with a positive test result who actually have the disease
negative: proportion of people with negative test result who don’t have the disease
What is the wilson and jungner criteria?
4 bits to it
the saying to help understand
knowledge of disease - important. disease understood. recognisable stage.
the screening test: suitable test. accepted by public
treatment: organisation and cost: cost of case findings balance out to possible expenditure. ongoing process
tx: accepted tx. enough facilities. agreed policies on who to tx.
In Exam Season NAP -
- important disease
- effective tx available
- simple and safe
- natural hx of disease known
- acceptable - not too invasive
-policy on who to tx agreed
calculations with sensitivity and specificity and positive predictive value and negative predictive value
sensitivity: a/a+c
specificity: d/b+d
positive predictive: a/a+B
negative predictive: d/c+d
(REFER TO PAPER TABLE I HAVE MADE)
What is a length time bias?
what is a lead time bias?
length time bias - disease that progresses more slowly is more likely to be picked up by screening which makes it appear that screening lengthens life.
lead time bias - early identification by doesnt alter the outcome but appears to increase survival as pt has the disease identified earlier than normal.
what is a selection bias?
what is an information bias?
what is an allocation bias?
what is a publication bias?
selection - error in selection of study participants. allocation of participants to different study groups.
information - observes recall and reporting, participants, instrument wrong calibrated
allocation: different participants in different groups - not equally spread
publication - trials with negative results less likely to be published
what is confounding?
when a factor is associated with the exposure of interest and independent influences the outcome but doesnt lie on the causal pathway
not part of the exposure and the outcome but influences both. almost like air pollution for when the exposure is smoking and the outcome is lung cancer. but doesnt lie on the pathway from exposure to outcome.
eg:
lack of exercise causes weight gain but there are other confounding variables that also cause it
in a study design
tell me the hierachy of evidence
systematic reviews and meta analysis
randomised control trials
cohort studies
case-control studies
cross-sectional studies
case series and case reports
editorials and expert opinions
what is a case control study?
give me the advantages and disadvantages of it?
retrospecitve observational study look at cause of disease.
compare similar participant with disease to controls without.
advantages;
- good for rare outcomes
- quicker than cohort or intervention studies (outcome already happened)
- can ix multiple exposures
disadvantages:
- difficulties finding controls to match with case
- prone to selection and information bias
how would the design of a case-control study be?
you have exposed and unexposed for people with the disease
exposed and unexposed to ppl without the disease
what is a cross-sectional study and what are the advantages and disadvantages for it?
retrospective observational collects data from population at specific point in time “snapshot”
prevalence of risk factors and itself.
advantages:
- relatively quick and cheap
- provides data on prevalence at single point in time
- good for surveillance and PH planning
disadvantages:
- risk of reverse causality (did outcome or exposure come firsT)
- cannot measure incidence
- recall and response bias risk (may miss quick recoveries)
what is a cohort study?
advantages
disadvantages
prospective longitudinal study looking at seperate cohorts with different tx or exposures. wait to see if disease happens.
advantages:
- can follow-up group with a rare exposure
-good for common and multiple outcomes - establish disease risk and confounders
-less risk of selection and recall bias
disadvantags:
- take a long time
-people drop out
-need large sample size, expensive and time consuming
design of a cohort study
you take people without a disease from population.
split into exposed and not exposed.
then for each split the disease and no disease. (does it happen or not?
what is a randomised control trial/
advantage
disadvantage
prospective study, all participants randomly assigned exposure or control intervention
advantage:
- low risk of bias and confounding
- can infer causality
diadadvantages:
-time consuming, expensive
-drop outs
- inclusion criteria may exclude some populations
how would the design of an RCT look like?
study population
then select by defined criteria
then potential participants - non participants are those who dont meet inclusion criteria
then invitation to participate
the participants
then randomisation
then some give treatment and some control
what is an ecological study?
look at prevalence of the disease over time - population data rather than individual
can show prevalence and association but not causation
what does it mean by odds - as a type of probability and how to work out?
what is an odds ratio? how to calculate?
for binary outcome - disease occurs or it doesnt
divide probability of it happening or not
odds = probability events occurs - p / probability events doesnt (1-p)
compare odds of an outcome occuring between 2 groups - 1 being exposure/tx and other control group :
odds of an events (condition a)/ odds of an events (condition b CONTROL)
if odds ratio is =1 it means?
if odds ratio is more than 1 it means?
if odds ratio is under 1 it means?
1 means that there is no association between the exposure and the outcome. In other words, the odds of the outcome occurring are the same for both the exposed group and the unexposed group.
if odd is over 1:
- events odds high for group/condition in numerator. risk factor
if under 1:
- probability of outcome occurring lower than the exposed. - protective factor/tx provided
4 types of information bias
measurement - different equipment measuring differently
observer - observers expectations influence reporting
recall: - past events not recalled correctly
reporting: people dont tell truth because of shame/judgement
publication bias is?
trials with negative results less likely to be published
What is the bradford-hill criteria for causality?
strength - strength of association
dose-response - does a higher exposure produce higher incidence?
consistency - similar results in different studies and populations
temporaility - does exposure precede the outcome?
reversibility - removing exposure reduced risk of disease
biological plasuibility - does it make sense biologically?
coherence - logical consistency with lab info : incidence of lung cancer with increased smoking is consistent with lab evidence that tobacco is carcinogenic
analogy - similarity with other established cause-effect relationships in the past like thalidomide in pregnancy, not other teratogenic drugs show similar effects
specificity - relationship specific to outcome of interest: introducing helmets reduced head injuries specifically, it wasnt that there has been an overal injury rate.
what does it man by reverse causality?
- bradford hill criteria?
stress could have caused htn - rather than htn causing stress
why would you get results that suggest that the exposure influences the outcome
bias
confounding factors
chance
reverse causality
true assocation- meet the bradford-hill criteria
define epidemiology
define incidence
define prevalence
define person time
study of frequency, determinants and distribution of diseases and health related states in populations in order to prevent and control disease
incidence: no. of new cases over a certain time period
prevalence: no. of people with a disease at certain point in time
person time: measure of time at risk for all pts in study - eg 1000 pts studied for 2.5 yrs - your study looks at 2,500 person yrs
explain the diff between incidence and prevalence
incidence changes with time, new cases
prevalence - number at set time of existing cases
so eg:
30k student in sheff.
3,600 have asthma.
over past 10 yrs they have 1000 new cases diagnosed.
incidence:
(1000/30,000)*100= 3.3% per 10 yrs
prevalence - 3600/30000*100= 12%
define health behaviour
illness behavior
sick role behaviour
aimed to prevent disease - eg regular exercise
illness behaviour - aimed to seek remedy- going to the doctor
sick role behaviour - aimed at getting well - take meds
perceptions of risk influence by?
health
- lack of personal experience with problem
- belief that it is preventable by personal action
- belief that if it has not happened by now, its unlikley
- belief that the problem is infrequent
points at with intervention are thought to be more effective - transition points
leaving school
entering workforce
becoming parents
becoming unemployed
retirement and bereavement
tell me the different models of behaviour change
health belief model
theory of planned behaviour
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 will change their behaviour if:
- believe are susceptible to the condition
- believe in serious consequences
- believe taking action reduces susceptibility
- believe that taking benefits of action outweigh the costs.
+ a cue to action
Stages of change - transtheroretical model
precontemplation - no intention of changing behaviour
contemplation - aware of problem but no comitment to action
preparation - intent on taking action to adress problem
action - active modification of behaviour
maintenance - sustained change, new behaviour replaces old
relapse - fall back into old patterns
what is an addiction?
craving, tolerance, compulse drug seeking behaviour, withdrawal
what can you offer a newly presenting drug users?
screening for blood borne virus
health check
sexual health advice/contraception
check immunisation hx
signpost to drug services
what is positive conditioning in drug users?
negative conditioning?
addiction increases desire to use drug.
people dont quit due to unpleasant symptoms.
principles of treating drug users?
reduce harm to user and family./friends
improve health
stabilise life
reduce crime
how does heroin work?
sx?
side effects
acts on opiate receptors
euphoria, miosis, drowsiness
dependence, bad withdrawals, nausea, itching, sweating, constipation, resp depression
what is an opiate detox
benefit of the 1st drug
methadone - helps transition - free no theft not injected
naltrexone and buprenorphine used too
cocaine crack
method of use
how it works
side effect - leads to what?
oral/snorting/iv smoking
blocks reuptake of serotonin - intense pleasurable sensation
depletion at secretory neurons - anxiety, panic, adrenaline secretion, wired.
leads to depression, panic, paranoia
explain maslows hierachy of need
self-actualization - achieving ones full potential
esteem needs - prestige and feeling of accomplishement
belongingness and love needs: intimate relationships, friends
safety needs: security,safety
physiological needs: food water warmth rest
self-actualisation is self fullfillment
esteem and belongingness is psychological and safety and physiological is basic needs
screening questionaire for alcohol dependance
how to calculate units?
cage questioniare
audit - if score over 15 go to specialist
units : volume (l) * % of alcohol = units
alcohol dependence - level of dependency - factors
withdrawal sx
cravings - very strong desire to drink
drink despite negative consequences: physical, mental or social/work life
tolerance - individual has to drink larger amount to get similar effect
primacy - put drinking before other activities - neglect other activities
loss of control
narrowing of repertoire - start to drink only 1 type of drink in 1 place
treating alcohol dependence
disulfiram - promote abstinence - alcohol intake causes severe reaction due to inhibition of acetaldehyde dehydrogenase
acamprosate: reduces craving, weak antagonist of NMDA receptors, improves abstinence in placebo controlled trials
CI of disulfiram
IHD psychosis
barriers to health for refugees
reluctance of gps to register them
illiteracy
communication
lack of permanent site
mistrust of professionals
what is an asylum seeker?
what is a refugee?
what happens if persons asylum seeker claim refused?
someone applying for refugee status
someone grafted asylum status for 5 yrs
only access emergency nhs services- get charged after.
what healthcare benefits do refugees get ?
vouchers to live off- sometimes restricted where they can spend
NASS support package
access to nhs
not allowed to work initially, no control over location
what kind of health problems for refugees?
injury/illness from war/travelling
communicable disease
lack of health screening and immunisation
malnutrition
untreated chronic disease
mental illness
explain malnutrition
deficiencies, excesses or imbalances in persons intake of energy and/or nutrients.
covers 2 conditions:
undernutrition - stunting - low height for age, wasting - low weight for height, underweight - low weight for age, and micronutrient - deficiencies or insuffieincyes - lack of important vits and minerals
overweight, obesity and diet related noncommunicable diseases - heart disease, stroke, diabetes, cancer
what is triple burden= micronutrient deficiencies - hidden hunger
tell me the 4 dimensions of food insecurity
availability (affordability) of food
access - economic and physical
utilisation - opportunity to prepare food
stability of 3 dimensions over time
tell me all the different ways there can be error in practise by the doctor
sloth error: being lazy, not checking results/info for accuracy
lack of skill: lack of appropriate skills or teaching in practise
communication breakdown: unclear instructions or plans and not listening to others
system failure: machine/equipment stopped working
human factors: bravado, timidity
fixation/loss of perspective = focus on 1 diagnosis = confirmation bias
judgement failure
neglect
poor performance
misconduct
mistriage = over/under estimating the severity of the situation.
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 is the bolam rule?
what is the bolitho rule?
bolam - would a reasonable doctor do the same?
bolitho - would that be reasonable?
4 aspects of negligence and error
was there a duty of care?
was there a breach of that duty?
was the pt harmed?
was the harm due to the breach of care?
explain the swiss cheese model of error
falling through the holes because there is failed or absent defences against error happening. - called latent failures.
organisational influence (to) unsafe supervision (to) preconditions for unsafe acts (to) unsafe acts
what is the bucket model of error
self = poor knowledge, fatigue, little experience/skill, feeling unwell
context = distraction, poor handover, lack of team support, equipment
task = errors, take complexity, new task, process
what is never event?
serious largely preventable pt safety incident that shouldnt occur if available, preventative measures have been implemented.
eg:
wrong site for surgery
wrong drug given
escape of psychiatry pt
what is a duty of candour
every healthcare professional must be open and honest with pts when something goes wrong with their tx causes, or has the potential to cause, harm or distress
define epidemic, pandemic, endemic, hyper-endemic
epidemic - more than expected incidence in a country
pandemic - more than 1 country
endemic - persistent level of disease occurence
hyper-endemic - persistently high level of disease occurence
features of a disease that make it a public health concern
high mortality
high morbidity
highly contagious
expensive to treat
effective interventions
tell me about childhood consent - fraser and gillick
never inform parents - encourage them to inform
under 13s can never consent to sex - inform social services.
fraser guidlines
- does she understand the advice?
- has the dr encouraged her telling the parents?
- will she have sex anyway?
- is the mental/physical health going to be effected if you dont give it
- best interests
gillick’s competence
- does a child under 16 have capacity to make own medical decisions?
-clinical judgement made by the dr: age capacity, maturity
what is the donabedian framework of health service evaluation?
issues with health outcomes?
structure - what actually is the service eg: how many heart surgeons there are
process - how does the process work
outcome - 5 Ds = death, disease, disability, discomfort, dissatisfaction
issues with health outcomes:
- link between health service and health outcome can be difficult to confirm
- time lag between service and outcome may be long
-large sample sizes may be needed
-data may not be available or have a problem with it (CART= completeness, accuracy, relevance, timeliness)
