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?
