public health Flashcards
what are the basic economic problems when thinking about health care?
- resources are finite (scarcity)
- the desire to do good and services that could be provided are infinite
- no country treats all of the ill people in the country because they don’t have the capacity to do so
- therefore the choice on where to provide health care cannot be avoided
what is the opportunity cost?
the opportunity cost of an activity is the sacrifice of benefits of other activities not chosen in order to choose the activity you fund
what is efficiency? (in terms of health economics)
efficiency is achieved when resources are allocated to activities to maximise benefit
what is an economic evaluation?
- the method used to asses whether resources have been used efficiently
- are the incremental costs worth the incremental benefits?
what are the three types of economic evaluatoin? describe what they are.
- cost-effectiveness analysis (incremental cost per life year gained)
- cost-utility analysis (incremental cost per quality life year gained)
- cost benefit analysis (net monetary benefit)
what is equity in terms of health economics?
the fairness or justice of the distribution of costs and benefits
opposing views on what fair is so difficult to quantify
what is health?
a state of complete physical, mental and social well being; not the absence of disease
what is the relationship between life expectancy and social class?
- as social class increases, life expectancy increases
- this gap is getting wider (thanks tory pigs)
what is the relationship between type of disease and social class?
- when a country reaches a certain threshold of income epidemic diseases of poverty are replaced by degenerative disease
- further increase income has no effect on the health of the nation
- unequal societies have worse health
what is social class?
- measure of occupation, social position, stratification and access to power and resources
- quantified using - registrar general (occupation focused) - NS-SEC model
what is the inverse care laws?
-those that require good medical care are often those that are most unable to access it
define incidence and state how it can be increased or decreased.
- the number of new cases per unit time
- increased - use screening to identify new cases and risk factors
- decreased - reducing risk factors (primary prevention)
define prevalence and state how it can be increased and decreased.
- number of existing cases at a point in time
- increased - screening, if risk factors increase, increased life expectancy due to better treatment
- decreased - cures for conditions and reducing risk factors
define sociology .
- the study of social relations and social processes
- it is a measure of social inter dependencies
- social structures - religion, family, medical profession etc. etc.
what is the role of the sick? (characteristics of someone who is adopting this role)
- they are exempt from normal social roles
- they are not responsible for their condition
- they should try to get well
- they should seek help from/cooperate with the medical profession
what is the medicalisation hypothesis?
-doctors see everything medically - this may be a problem when a condition is actually a product of the patients social environment ie depression
define iatrogenesis.
unintended effects of a therapeutic intervention.
what is the health belief model?
- a psychological model that attempts to explain and predict changes in health behaviours
- perceived susceptibility, barriers, benefits and self efficacy are all influences in changing behaviours
what is the stages of change model? (6 stages)
1) not thinking/pre-contemplation model
2) thinking about changing/ contemplation
3) preparing to change
4) action
5) maintenance
6) stable changed lifestyle or relapse
what are some other factors that change behaviour?
- motivational interviewing
- social marketing
- nudge theory (changing environment to make healthier option the easies)
- mindspace
- financial incentives
define public health.
- concerned with health protection, promotion and improving and organising health sciences
- can be local, regional, national, international or make you want to commit suicide
what is happening to world’s populations?
- population size is increasing
- infertility is increasing
- the elderly population is increasing
what is the definition of CAM (complementary and alternative medicine)?
- a broad domain of healing resources that encompasses all health systems, modalities, practices and their beliefs
- healing resources that aren’t part of the domminant health system of a particular society or culture in a given time
what are some names for CAM?
- complementary
- alternative
- folk
- non allopathic
- unorthodox
- traditional
- energy medicine
what are the NHS perspective ‘BIG 5’ in regard to CAM?
- acupuncture
- chiropractice
- homeopathy
- herbal medicine
- osteopathy
what are the major concerns with CAM?
- unrealistic expectations
- delayed conventional treatment and care
- general safety - unregulated practitioners and treatments - unknown drugs interactions
What would cause a person to seek CAM?
- lack of effectiveness of conventional treatment
- concern about unpleasant
- experience of poor communication with doctors therefore rejecting science
- disease isn’t serious enough
- high patient satisfaction rates
- gullibility and naivety
who mainly uses CAM?
- 35-60 mainly women
- higher income and education
- poor health status - 60% have a chronic disease
- geographical variation - southerners do it more - southern twats
- autism spectrum disorders
what is the point of screening?
- it’s a form of secondary intervention
- indentifies individuals that are more likely (not certain) to have a disease
what are true and false positives?
true +ves = positive test results when the person has the disease
false +ve = positive test result but the person doesn’t have the disease (also known as type 1 effor)
what are true and false negatives?
true negative = negative test result and person doesn’t have the disease
false negative = negative test result and person does have the disease
what is sensitivity? (of a test)
- number of true positive results/total number of results
- measures how well a test picks up those with a disease
what is specificity? (of a test)
- number of true negative results/total number of results
- measures how well a test recognises those without a disease
what is prioritised when designing a test, sensitivity or specificity?
sensitivity - the effect of missing the disease is worse than the trauma caused of a false positive result
this increases the number of false positives
define positive and negative predictive values.
PPV - the proportion of people with a +ve test result who have the disease
NPV - the proportion of people who are correctly excluded by the screening test
what is the relationship between PPV + NPV and prevalence + incidence?
- if prevalence is high = false positives fall, PPV increases and NPV decreases
- if prevalence is low = false positives rise, PPV decreases and NPV increases
give three examples of screening tests.
- Gothrie test - new borns heal prick test. tests for phenylketononia, CF, sickle cell.
- PAP test - cervical smear test for cervical cancer
- PSA test - prostate specific antigen test for prostate cancer
what are the principles of screening?
- condition tested for should be important
- should be acceptable treatment
- there should be a recognised early or latent stage
- there should be a suitable test that should be acceptable to the whole population
- the cost of case finding should be economical should be balanced in relation to the possible expenditure as a whole
what are the arguments for and against screening?
for - prevent suffering, early intervention improves outcomes of treatment, early treatment is cheaper
against - damage and distress that may be caused by false +ves and -ves, personal choice is compromised
define primary intervention and give examples.
- aims to prevent disease becoming established
- to reduce/eliminate exposures or behaviours that are known to increase a patients risk of developing a disease
-smoking cessation, vaccinations, proper dental hygiene and hospital decontamination
define secondary intervention and give examples.
- aims to detect a disease early and slow down/halt it’s progress
- screening - mammography, blood sugars, PSA, PAP etc
- low Na+ diet and daily exercise to prevent further MI or stroke
define tertiary intervention and give examples.
- aims to reduce complications and severity of disease softening the impact of chronic illness or injury that has long lasting damage
- cardiac rehab post MI, HIV medication, chronic disease management plans diabetes, arthritis, depression etc.
what is the difference between eustress and distress?
eustress = positive beneficial and motivating stress
distress = negative, damaging and harmful
what are the 5 types of stress?
- biochemical
- physiological
- behavioral
- cognitive
- emotional
what is biochemical stress?
endorphins and cortisol levels are altered
what is physiological stress?
shallow breathing, increased BP, increased acid production in stomach
what is behavioral stress?
absenteeism, smoking, alcohol, stress eating, sleep disturbance
what is cognitive stress?
negative thoughts, loss of concentration, stress headaches
what is emotional stress?
mood swings, irritability, aggression, boredom, tearful
what are the two types of stress in terms of duration?
- acute - dangerous situation, noise, hunger, infection
- chronic - financial, work, relationship, children and friends
what are the 2 types of data?
- qualitative
- quantitative
what type of graph shows continuous data?
- stem and leaf diagrams
- histogram
- box and whisker
what types of graph show discrete data?
- bar charts
- pie charts
what are the three measures of spread?
- range
- interquartile range
- standard deviation
what is the standard deviation?
- The Standard Deviation is a measure of how spread out numbers are
- the average distance each piece of data is from the mean
what is normal distribution?
- bell shaped curve
- 2/3 of date lies within one standard deviation of the mean
- 95% lies within 2 standard deviations of the mean
- mean and median are the same in normal distribution
what is the prevention paradox?
- more people with a disease have a low risk of getting a disease
- less people with high risk of disease actually present with a disease
what is the high risk approach to prevention?
- target high risk individuals
- aims to reduce risk below a set limit
- accepted by society as we treat those ‘outside’ normal levels
what is the population approach to prevention?
- target all individuals
- aims to reduce risk for each individual
- recognises that low risk people contribute to most cases (prevention paradox)
- not as accepted by society (concerns with treating the well unnecessarily - nanny state)
what approach to prevention is best for what people?
high risk approach - best for rich and educated as they’re more likely to interact with the healthcare systems, comply with treatment, have the means to change their lifestyles
population approach - best for all individuals this approach reduces social inequality
what are some methods of primary intervention for CHD?
SNAP
Smoking - taxation, cessation, control areas and packaging
Nutrition - recommendations (low salt, 5 fruit and veg etc), food standards, sugar taxation
Alcohol - taxation and awareness campaigns
Physical activity - 5x per week and PE in schools
what are methods of secondary and tertiary preventions in CHD?
medical management - antihypertensives, statins, metformin, asprin
Cardiac rehabilitation
phase 1 - hospital
phase 2 - 1-4 weeks post discharge
phase 3 - 4-16 weeks post discharge
phase 4 - long term of maintenance and lifestyle changes
what are some unmodifiable risk factors?
- age
- sex
- ethnicity
- family history
- early life circumstances
what are some (potentially) modifiable risk factors?
physiological
- high cholesterol
- hypertension
- T2 diabetes
lifestyle
- SNAP
- weight and BMI
what are some psychological influences on health?
- personality - Type A = neurotic, hostile, impatient (all increase CHD risk)
- depression and anxiety
- work - high demand and low control = stress = poorer health
- social support - quantity and quality of relationships
what are some smoking statistics?
- more men than women though closing gap
- prevalence increasing
- low socioeconomic status = higher rates
- higher in homosexuals than heterosexuals
what reasons are cited for smoking?
- nicotine addiction
- coping with stress
- habit
- socialising
- fear of weight gain
what are the criteria for a pandemic spread?
- a novel virus capable of infecting and causing illness in humans
- large pool of susceptible people
- readily available/sustainable person to person transmission
what are the 4 main types of STI?
- chlamydia
- gonorrhoea
- syphilis
- trichomoniasis
what are some public health interventions for dealing with pandemics?
- hand washing
- reduce social contact
- travel restrictions
- school closures
- airport screening
- quarantine and barrier nursing
how can pandemics be spread?
direct
- direct contact ie STI
- faecal-anal route - ingestion of faecal matter
indirect
-vector borne ie malaria
airborne
-respiratory route ie TB
what are the recommended amounts of alcohol for men and women?
men - 3-4 units/day or 28/week
women - 2-3 units/day or 21/week
new guidelines
2 units/day or 14/week for both men and women
how much alcohol is in a standard unit of alcohol?
10ml or 8g of ethanol
what is the CAGE questionnaire?
accronym for 4 questions to assess whether a person has a alcohol abuse problem
- have you ever thought you should CUT down?
- been ANNOYED by people telling you to cut down?
- feel GUILTY about how much you drink?
- EYE OPENER! ever had a drink to get you out of bed in the morning?
what is compliance?
- extent to which a patient follows the treatment plan/advice of a medical professional
- paternalistic concept - assumes the doctor knows best, doesn’t take into account patients problems in managing conditions
why are patients non-compliant?
- accidental/unintentional ie forgetting to take meds or not understanding instructions
- intentionally - patient beliefs about their condition/treatment
- non-compliance is one of the biggest financial losses to the NHS
what is concordance?
- the concept of patients and doctors are equal in the care of the patient
- they are expected to take part in treatment decisions
when might a patient not take part in their own care?
- if they don’t have the mental capacity
- if their decisions are detrimental to their well being
- if they pose a potential threat to the health of others
- children - if child is of sufficient understanding they can give permission, if not guardian must consent
define and describe healthspan.
- the number of years during which one is healthy and free from serious disease
- assessment of limitation by via scales - Katz, Barthel, instrumental activities of daily living
- prevalence of chronic conditions increases exponentially during mid to late life
what is palliative care?
-improves the quality of life of patients and families who face life threatening illness by providing symptom relief and psychosocial support until end of life
can be specialist or generalist
what is the doctrine of double effect?
- if doing something good has a morally bad side effect it is ok to do if the bad side effect wasn’t intended. holds true even if you foresaw the bad side effects would probably happen
- relevant to giving terminal ill patients drug pain relief despite knowing it will shorten their life span
what are the four principles bioethics?
autonomy
-the patient is allowed self governance
-enables individuals to make informed rational decisions
benevolence - providing benefit balancing them against risks
non-maleficence - do no harm, reduce or prevent harm
justice - distribution of benefits, risks and costs fairly
what two things are required to construct a confidence interval?
- sample mean
- standard error
where is the 95% confidence interval found?
1.96 errors above and below the mean
what happens to the 95% confidence interval when with increasing sample size?
it gets smaller
what happens to the confidence intervals when the sample size is squared?
they half in size
what are the 6 steps to hypothesis testing?
- set null hypothesis as H0 and study hypothesis to H1
- carry out significant test
- obtain test statistic
- compare test statistic to hypothesisd critical value
- obtain p value
- make decision based on p value
what is usually the opposite of the null hypothesis?
the study hypothesis
what is the formula for test statistic?
(observed value - hypothesised value) / the standard error for the hypothesised value
what does the test statistic do to the data?
reduces the date to a single value
what is a p value?
the probability of committing a false error ie rejecting the null hypothesis when it is actually true
At what p value can the null hypothesis be rejected?
less than or equal to 0.05
what is the power of a study?
- the probability of rejecting the null hypothesis when it is actually false.
- the probability of concluding that there is actually a difference when a difference truly exists
how should data be summarised if it is symmetrical?
mean and standard deviation should be used
how should date be summarised if if is skewed?
median and interquartile ranges should be used
define positive skew.
- mode is less than the median which is less than the mean.
- mode
define negative skew.
- mode is greater than the median which is greater than the mean
- mode>median>mean
what is a reference range?
limits within which we would expect the majority of data to fall
what are two types of non-random sampling?
- convenience sampling
- purposive sampling
what are the 3 types of random sampling?
- simple random
- stratified random
- cluster
what is simple random sampling?
all within a population are equally likely to be picked
what is stratified random sampling?
the population is divided into groups and then randomly sampled within those groups
what is cluster sampling?
sample clusters of people
what is standard error?
the standard deviation of all the sample means. standard error is an estimate of precision. it provides a measure of how far from the true value the sample estimate is likely to be.
how is standard error calculated?
standard deviation divided by the square root of the number in the sample
what is the relationship between standard error and standard deviation?
the higher the standard deviation the higher the standard error.
define reliability.
how consistent the results are - if the experiment was to be repeated would similar/same results be found
define applicability.
how relevant a study is to clinical medicine
what shows study quality?
- random allocation
- suitably large sample size
- shows causation not association
what shows data quality?
CART
- Completeness
- Accuracy
- Reliability
- Timeliness
what are the three types of observational studies?
- descriptive
- descriptive and analytical
- analytical
what are descriptive studies?
- case reports of case studies - study individuals
- ecological studies - uses routinely collected data - shows trends; used to generate hypotheses but can’t establish causation
what are descriptive and analytical studies?
- cross sectional - divides population into those with and with disease
- collects data on them at a given time
- looks for association not causation
- no time scale/how things change
- generates hypotheses
what are analytical studies?
case control
- retrospective; people with disease matched to those without on a series of variables (sex, class, age etc) and study previous exposure to potential causative factors of disease
- quick inexpensive, only association, potentially poor reliability
cohort study
- start with a population without a disease, study of incidence
- are patients exposed to a causative agent and do the get the disease as a result
- prospective - can establish causation
define utilitarianism.
- an act is evaluated in terms of it’s consequences
- the act that benefits the most people is right
define deontology.
- a duty based approach
- do the right thing and do it because it’s right
- don’t do the wrong thing and avoid them because they’re wrong
- concerned with features of the acts themselves and not the consequences
define virtue ethics.
- concerned with the person carrying out the action
- the act can only be virtuous if it performed in the right state of mind and for the right reasons
what are the 5 virtue ethics?
- compassion - regard for others well being
- discernment - ability to make descions judgement without influence from external factors
- trustworthiness - confidence in ones character and conduct
- integrity - being consistent
- conscientious - doing whats right
what are the 5 features of evidence based medicine?
- asking focused questions
- finding the evidence
- critical appraisal
- making a decision
- evaluating performance
what are the 4 things involved in asking focused questions?
- right population
- specifically what is the intervention
- relevant comparison
- outcome
what is the hierarchy of evidence?
- a way of ranking the quality of data collected
- 1a = systemic reviews/meta-analysis of RCTs= gold standard
- 1b = at least 1 RCT,
- 2a = 1 non-RCT
- 2b = quasi experiments
what is critical appraisal?
an assessment of validity, reliability and applicability
define validity.
- how close to the truth something is
- is a studying testing what it says it is or are there confounding variables that are the actual cause of the results
what are experimental/interventional studies?
RCT
- randomly split into 2 groups
- intervention to one control to other
- measure outcome
- minimal confounding or bias
- large and expensive to run
- volunteer bias may be seen
- shows causation
what is the difference between a dependent and independent variable?
independent - variable that you change
dependent - variable that you measure dependent on the independent variable
what are the features of a causal relationship?
- consistency
- strength of association
- specificity
- dose dependent relationship
- biological plausibility and coherence with existing theories
what are some pros and cons of utilitarianism?
\+it's flexible there are no rigid rules \+accounts for lots of people therefore increases happiness of the world -individuality not taken into account -can't quantify it -there may be unforeseen consequences
what are some pros and cons of virtue ethics?
+person centered
+broad and non prescriptive - no single criteria for goodness
-broad and non prescriptive - can also mean no consistency ie can vary among cultures
what are some pros and cons of deontology?
+very rigid guidelines - no vagaries easily applied
+quickly applied - no need to weigh up consequences
-the duties are different for different people
-doesn’t take into account the person
what are necessary for capacity?
- ability to understand information
- retain information
- use information to make a decision
- communicate the decision
what is nominal data?
- no numerical significance
- type of discrete data
- non overlapping labels ie hair colour, place of birth
what is discrete data?
-can be numerical or categorical ie number or apples that are red or green
what is continuous data?
occupy any value over a continuous range ie age
what is ordinal data?
can be put into an order; can be abstract ie happiness on a scale from 1-10
what is interval data?
can be put into an order and we know the exact difference between the values ie temperature, time etc
what is binary data?
data is in one of two possible states ie yes or no, on or off
What is a clinically significant difference?
One which is big enough to be worthwhile. It is important that the size of the sample is adquate to detect the clinically significant result, at the 5% significance level with at least 80% power.
What is RISK?
The incidence divided by the population- also known as absolute risk
How is absolute risk difference calculated?
Risk in an exposed group - risk in unexposed group
What is relative risk?
The risk of an event in an exposed group divided by the risk in the not exposed group
What is number needed to treat to benefit?
The additional number of people you would need to treat in order to cure one extra person cmpared to the old treatment
What is number need to harm?
The additional number of individuals who need exposure to the risk in order to have one extra person develop the disease compared to an unexposed group
How do you calculate number needed to treat (NNT)?
1/absolute risk reduction
How do you calculate number needed to harm (NNH)?
1/absolute risk difference
Define odds.
ratio of the probability of an occurrence compared to the probability of a non-occurrence
How do you calculate odds?
probability/(1-probability)
Define odds ratio
Ratio of odds for exposed group to the odds for the not exposed group
How do you calculate odds ratio?
{P exposed/(1- P exposed)}/{P unexposed/(1- P unexposed)}
Which types of study allow the calculation of both relative risk and odds ratio?
Cross-sectional and cohort
In what instances would odds ratio be used instead of relative risk?
- If relative risk cannot be calculated
2. If it is unclear which is the independent variable and which is the dependent variable because it is symmetrical
Define a systematic review.
A review of a clearly formulated question that uses symptomatic and explicit methods to identify, select and critically appraise relevant research, and to collect and analyse data from the studies that are included in the review.
Define a meta-analysis.
A method designed to increase the reliability of research by combining and analysing the results of all known trials of the same product or experiments on the same subject
Define routine health data
Data on a population health etc. that is collected, collated and disseminated on a regular basis
Give four reasons why routine health data is collected.
- Monitor health of the population
- Generate hypotheses on causes of ill health
- Inform planning of services
- Evaluate and assess performance of policies and services
Give six examples of routine health data that is collected
- Mortality
- Morbidity
- Use and quality of healthcare
- Health status/quality of life
- Individual lifestyle
- Socio-economic, cultural and environmental conditions
Give three types of qualitative research
- Enthonography: emerging oneself in a particular lifestyle or group
- Interviews
- Documentary analysis
Give five problems with qualitative research
- interactive kinds: over-analysis of oneself using existing theories
- Meaning imposition: not truly understanding what someone else is thinking
- Crisis of representation: research cannot capture lived experiences
- Reflexivity: personal interpretations of data
- Generalisation
What is the difference between an absolute and relative risk?
Absolute gives an exact presentation of risk; relative presents the risk as an increase or decrease – doesn’t give you the baseline (must always ask – compared to what?)
Why do we use inferential statistics?
Uses the data to draw inferences about the population represented – what does our data mean?
What is regression and why is it used?
A way of assessing the relationship between variables, used to isolate the effect of a single variable on a clinical outcome – treatment, risk factor etc
What are four types of regression analysis and when are they used?
Logistic regression – used for odds ratio
Linear regression – used for mean difference
Poisson regression – used for incidence rate ratio
Cox regression – used for hazard rate ratio
What is the difference between positive and negative confounding?
Positive – overestimates the true value
Negative – underestimates the true value
what are the duties of a doctor?
Make the care of your patient your first concern.
Provide a good standard of practice and care.
your competence.
Take prompt action if you think that patient safety, dignity or comfort is being compromised.
Protect and promote the health of patients and the public.
Treat patients as individuals and respect their dignity.
Work in partnership with patients.
to improve and maintain their health.
Work with colleagues in the ways that best serve patients’ interests.
what does PICO stand for? what is it used for?
population (P), intervention (I), comparison (C) and outcome (O). used to find the answer of a question.
