Public health Flashcards
what is primary disease prevention
prevention of disease onset - target risk factors
what is secondary disease prevention
early detection and optimise progression such as screening
what is tertiary disease prevention
effective symptom management and slowing of progression with things such as medication and surgery
what is quintenary disease prevention
prevention of overmedicating the patient
what is the prevention paradox
measures to improve public health will have little effect on most people
what is a tests sensitivity
it is the correct identification of a disease
how do you work out the sensitivity
true positive / (true positive + false negative)
what is a tests specificity
how well it correctly excludes negative results
how do you work out a tests specificity
True negative/ (true negative + false positive)
what is the positive predive value
it is all those who are positive who tested positive
how do you work out the positive predicted value
True positive/ (true positive + false positive)
what is the negative predictive value
it is all those who are negative who test negative
how do you work out the negative predictive value
True negative/(true negative + false negative)
what are the criteria for a successful screen
WILSON JUNGNER
Important problem
Available diagnosis and treatment facility
Treatable
recognisable latent stage
obvious diagnosis test
general public accepted
economically viable
natural history of untreated disease known
issued agreed policy (who to treat)
continuously done (not abruptly stopped)
what is lead time bias
this is that screening earlier gives an apparent increase in life expectancy
what is length time bias
this is slower progressing diseases are more likely to be picked up on screening than rapidly progressing ones
what are the types of study design
ecological
cross section
case control
cohort
randomized control trial
systematic review
what is an ecological study
it is an observational study - censes, population data
what are positives and negatives of an ecological study
positives: readily available data, shows correlation
negatives: cant show causation, biases and other confounders
what is a cross sectional study
it is a retrospective observational study, stops at a point in time and looks at risk factors and disease development at this time period
- identified prevalence
what are positives and negatives of a cross sectional study
positives: large samples, Data on all variables are only collected at one time point, Multiple outcomes and exposures can be studied, quick and inexpensive
negatives: reverse causality can occur, there can be length time bias, cant use for rare diseases
what is a case control study
this is a retrospective study which is establishing risk factors and disease relationship with a positive and negative group
- identifies predictors of outcomes: odds ratio often used
what are positives and negatives of a case control trial
positives: rapid and are good for rare diseases
negatives: reverse causation and are bias prone
what is a cohort study
it is a prospective longitudinal study: uses positive and negative groups which are followed up with exposure or nor not over time
what are positives and negatives of a cohort study
positives: can show causation
negatives: takes a long time to complete, can be expensive, there may be a change in behaviour in the cohort, loss to follow up
what is a randomised control trial
it is the most rigorous - blinded or double blinded groups with a placebo, looking at exposure and then followed up over time
what are positives and negatives of a RCT
positives: gold standard for causation, can balance the arms
negatives: change in behaviour of cohorts, ethical issues, loss to follow up
what are positives and negatives of a systematic review
positives: combines studies therefore more effective data and higher statistical power
negatives: ignoring differences between studies, bias prone, depends on other data
what is the incidence of a disease
the number of new cases a population in a given time
what is the prevalence of a disease
it is the total number of cases in the population at a given time
what is the meaning of person years
it is the unit of measurement that represents the number of ears that a person contributes data until they are lost to follow up, the disease develops or the study ends
what is a confounder
it is an associated factor which independently affects the outcome
what are the types of biases
selection bias
information bias
publication bias
and lead and length time bias
how do you determine causation
use the BRADFORD HILL CRITERIA
1. must be dose response
2. must be reversible
3. must be consistent
4. must have biological plausibility
5. temporality
6. coherence
7. analogy
8. strength
9. specificity
what are factors for causation
change
confounder
causation
correlation
and bias, reverse causation
what are the public health domains
- Improving health promotion: reducing inequality through education, employment
- Protection of health (environmental and occupational hazards identified)
- Service improvement (audits, equity)
what is equality
part of deontology - everyone deserves the same thing
what is equity
this is fairness: everyone deserves enough for success
what is horizontal equity
equal treatment for equal needs for example the same income tax
what is vertical equity
unequal treatment for unequal need i.e managing severe T2DM vs newly diagnosed
what are the three levels involved in interventions for equity
individual
community
population
what are promoting health behaviours
health behaviour - maintenance of good health
illness behavours - seeking remedy
sick role - aimed at recovery
what are reasons for damaging health behavours
reasons: cultural, unrealalistic optimism ( problem is infrequent, unlikely, lack of experience with problem, preventable), stress
what is the Becker model of behaviour/ health belief model
Health Belief model 1974
pervieved barriers is the most important determinant of change
- believe they are susceptible
- believe it has serious consequences
- believe that taking action reduces susceptibility
- believes cost of taking action outweighs carrying on
what are positives and negatives of Becker model of behaviour
Positives: long standing use, applicable in lots of situations
Negatives: no emotional or social cues, no temporality, no differential diagnosis list vs repeat illnesses
what is the transtheoretical model of behaviour
precontemplation
contemplation
preparation
action
maintenance
(+relapse)
what are the positives and negatives of the transtheoretical model of behaviour
positive: temporality, and accounts for relapse
negatives: people may not go through all states, people can go forward and back, there are no social cues involved
what is the theory of planned behaviour
a positive attitude, subjective norms and perceived behavioural control all act together to give someone intention to change which then becomes action
what are positives and negatives of the theory of planned behaviour
positives: accounts for emotional cues, lots of scenarios
negatives: lack of temporality, report bias
what is the nudge theory of behavioural change
fruit next to the checkout rather than sweets
what are Bradshaws health needs
Felt
Expressed
Normative
Comparative
what is the health needs assessment cycle
assessment - planning - implement - evaluate - assessment etc
what are different assessment approaches to health needs assessment
epidemiological
comparative
corporate
what is the epidemiological assessment approach
Top down approach, defines size, issue and service (Biomedical data on the population, capacity to benefit and with what service)
- issue is there is no felt or expressed need taken into account
what is the comparative assessment approach
comparing two demographically different services - how does our service compare to others
- issue is they may compare two bad services or two good services so there is no baseline