HADPOP 2 Flashcards
What is health?
What is public health?
Absence of infirmary
The prevention of disease, prolonging life + promotion of health in society through organised efforts
Public health model
- Surveillance - WHAT IS THE PROBLEM?
- Risk factor ID WHAT IS CAUSE?
- Intervention + evaluation SOLVE>
- Implementation - HOW TO INTERGRATE INTERVENTION
Who arethe 3 stakeholders in public health?
State examples of key public health interventions
- Vaccination programmes - HPV
- Motor vehicle safety - THINK road safety campaign
- Family plannig- FREE CONTRACEPTION
- Infectious disease control - HIV, COVID-19
What is the difference between equity and equality
EQUALITY - eveeryone recieves same thing regardless of situation - SAMENESS
EQUITY - everyone recieves what they need based on their individual circumstances - FAIRNESS
What is the definition of health equity ?
Absence of avoidable differences among groups of people
Deals with rising issues made prevalent by socioeconomic deteminants of health
What are socioeconomic determinants of health?
- Race
- Gender
- Job
Where you live
Where you were born
What is health inequality ?
Health variation that is
1. Unfair
2. Avoidable
Directly related to inverse care law
What is inverse care law?
Good medical care less available to those who actually need it compared those who don’t
What are the two main types of health surveillance?
- Routine
Encompases whole population
Demographics, health events
GOOD FOR TREND MONITORING
regular intervals - Ad Hoc
Study done when there is a specifc need for a study to be conducted. No intetion of repitition
State 3 pros and 3 cons of routine data
Pros
- Readily available
- limited costs
- Trend monitoring
Cons
- Bias
- Poor presentation
- Limited determinants details, focus on conditions not causes
What is a population cencus?
What important info can we get from a cencus?
Pros of cencus
Cons
Recorded demoghraphic data by govt - specific time, pertains to all persons in that area
Info:
- Unemployment
- deaths
- lack of amenities
Personal enumeration
Regular occurance
Govt tun
Cons
- General statements about population
How do we apply cencus information?
What do we use population pyramids?
POPULATION PYRAMIDS
- Allow us to make predictions regarding the future demographics of population - predict services required (population estimates (current application) or population projections (future application))
What is the difference between fertilty and fecundity
Fertility - ability to produce offspring
Fecindity - Ability to produce life offspring
What is the difference between birth notification vs birth registration
Birth notification - Done by midwife, within 36 hours to child health register
Birth reg - parent, 42 days
What is the difference between mortality certification and mortality regstration ?
Cert - doctor responsibility, info of likely cause of death
Reg - qualified info, 5 days fo death, requires death cert from dr
What are notifiable diseases?
Give 5 examples
Disease that can lead to public health crisis
Must be reported to UK HAS when detected
- Cholera
- Botulism
- Malaria
- TB
- Whooping cough
What is under reporting?
Why can it occur?
- Specific disease + prevalence not accurate, due to incorrect monotring of conditions
Why?
- Lack of Dr knowledge
- Misdiagnosis
-How commin the condition is
- Decreased severity
Conditions affecting men vs women
What do scatter plots show?
How can we describe them?
Relationship between two continous variables
Liner / Non - linear
STRONG/WEAK correlation (how close together dors are)
Correlation coefficient
Slope
-positive
-negative
-0 if not postive or neg
What is a correlation coefficient?
Number that shows the strength of correlation between two variables
- If +1, X causes Y
- If -1. X does not cause Y
What are the two ways we use to measure disease?
- Incidence
No. new cases - Prevalance
No of cases of disease in population at specific time
Formula for incident risk and rate
What is point prevalance ?
Formula?
What factors change prevalance?
Number. of cases (past, current) at specific time peroid as proportion of
total numebr of ppl in population
- Chance
- Demgrhaphics
- Ttreatment
- True changes
What is the difference between risk and association?
Risk - probability outcome will occur
Association - correlation between exposure and outcome
(causation, correlation)
What is the formula for relative risk?
Risk ratio
Incidence risk in exposed / incidence risk in unexposed
RR> 1 - positive assication
RR < negative association
What are the 4 levels of prevention?
Primary - prevent illness
Secondary - earlty diagnosis, minimise effects
Tertiary - prevent further complications
Primordial - remove disease from population enitrely
Stages of change model
Relapse/Prolapse
Pre-contemplation
Contemplation
Preperation / determination
Action
Maintenance
The 6As
As
Acknowledge
Asess
Assist
Advise
Arrange
How many units per week is the limit for men and women?
14 units per week regularly
What does the CAGE questionnaire stand for?
Cut back
Annoyed
Guilty
Eye opener
What is “pack years smoking” ?
Determines how many cigarettes a person has had in lifetime
What is the definition of a survey?
What are 3 purposes of surveys?
Investigation, info systematically collected and experimental not used
- Measures risk in population
- Measures outcomes
- Assess prevalence of diseases
What type of study is a prevalance study?
pros, cons
- Cross secrtional
- Snapshot in time
QuicK
Good for trend planning
NOT GOOD FOR SHORT TERM CONDITIONS
NOT USED FOR CAUSATION
What is a sample?
Why do they need to be representative of whole population?
What is a sample frame?
- Representative subset of population
- To make accuate inferences about population
- List of everyone in population that can be sampled
What makes a good sample group?
- Large sample size
- Random
- Representative
Quality vs Quantity
Sampling methods
- Random
equal probability of drawing anyone in frame being chosen - Cluster - natural cluster
- Simple - ID + selection
- Stratified - dividing of population into strata
- Systematic - very nth member, good for preserving representation
- Non-random
-easier
-covenient
What errors can you have with systematic sampling?
What erros can we have with random sampling?
Bias - intrument failure
Random - altered results, due to chance
Explain two sources of bias
- Selection bias
- Sampling (non representative)]
-Non response bias - Information
- Instrument (equipment incorrectly calibrated)
-Interobserver (3rd party observer irepretate things differently yo how respondent means them)
Confounding Bias
Lack of comparability between exposed and
unexposed populations
Precision vs Accuracy
Accuracy - How close to expected value results are
Low accuracy = random error
Precision
How close together results are
Low precision - systematic error
Health protection services
Surveillance+ control of new and recurrent infections
National coordination- UKHSA
Regional coordination - HAS
Local - Health protetion teams
What is routine surveillance?
Regular collection of data from one source (GPs, health clnic, local hoospital records)
- Age
- Sex
-Health problems - Current access to healthcare
What is the difference between passive and active surveillance?
Passive - regular reporting from hospitals, GP, to govt body.
Active - govt asks specific health teams to make reports on specific health groups
What to CCDC do?
- Interview affected indivduals
- Confirm dianosis
- Tracing contacts of index case
4/ Identification + prevention
What are limitations of surveillance?
- Lack of denomintators
-Under reporting - Lack of representativeness of reported cases
- difficult to interpret trends
Descibe process of transmission
Index - first case identified
Priamry - case brings condition into population
Secondary - infected by primary
Tertiary - infected by secondary
- IT SPREADS
What is a reservoir?
Host whhich is not affacted by virus
Viurs safely grows, replicates, lives
e.g. kangaroos for ross river vius RRV
What is a vector?
Host that can carru + spread pathogens
e.g. mosquitos for RRV
State features of an endemic outbreak
- Constant rates of cases in population
- Disease rate is predictable, managed by local healthcare teams
- Limited to specific area
- Occurance of cases is at expected frequency
What is an epidemic?
What is a pandemic?
Increase in number of expected cases
Pandemic - global epidemic
What is a healthcare acquited illness?
2 causes
- Any illness caught in healthcare setting
- Resistant pathogens
- Inapropriate isolation
How can limit presence of reservoirs and vectors?
Wearing long clothing, not going to place durng speicif season
Why do we limit immediate sources?
People who are immediately affected
Prevent presence of excess sources of pathogens
What do we need to tackle to prevent spread of disease?
- Immediate sources
- Reservoirs, vectors
- Mode of transmission
- Susceptible - protective isolation
Why do we source isolate?
What are the room conditions for isolation
- Unexplained rashes
- Suspected communicable diseases
- Infleunza symptoms
- Resistant viruses
SINGLE VENTILATED ENSUITE ROOM
Negative pressure
Why do we protectively isolate?
Difference in conditions between this and source isolation ?
- Immunocompromised individuals
- Pregnant patients
- Frail
Difference - positive pressure in room
Evidence Based Medicine
Give an example of a database for medical research
What is PICO?
Pubmed, Google scholar
PICO
- population
- intervervention
- comparison
-outcome
What is meant by “health need” ?
What do we need to consider during health needs assesment?
What has capacity to benefit health population group as a whole
WHO
WHAT
WHERE
WHEN
HOW
How do we conduct a randomised control trial? Clinical trial
- Randon assignment of patients
- Control vs treatment groups
- Adminster placebo and medication
- Compare results
What is blindng / masking? Benefit
What are the types?
Hiding info about who is getting which treatment (Concealment of intervention allocation)
Reduce measurement bias
Types
- Single - patient does not know
- Double - patient, dr does not know
- Tripple - patient, dr, researcher
How do we reduce bias in RCTs?
- Measuremet bias - blinding
- Allocation bias - allocation concealment
What is placebo effect?
Placebo - inert substance idenical to intervention in every wy
Attitude patient has towards a medication can influence their health ourcome and can lead to the feeling that something positive happened
State advantages of RCTs
Disadvantage
- Unbiased distrobution of confounders
- Blinding
- Randomisation
-ve
- Epensive
- Ethically problematic
- volunter bias
What is intention to treat?
Comparitive step
Compares outcome for
- intervenion group patients
with
-control group pations
Shows if intervention would be useful in clinical practice
Describe the differnce betwene causation and association
What are the 7 Bradford Hill Criteria?
- Strength assocation
- Dose-response relationship
- Consistency of findings
- Biolocal plasuability
- Coherence of evidience
- Specificity of association
What is a confounder?
Third variable impacting results of experiment trial
What type of study is a cohort study?
Observational study
Where you follow a group of people over time and see how different factors (exposures) affect likelihood of developing certain conditions.
What is relative risk?
Risk of contracting disease based on exposure level to specific exposure
How do we interpretate relative risk?
RR =1: NO DIFFERENCE
RR > 1: exposure increases risk
RR < 1: Exposure is protective
What does it mean by “95% confidence interval?”
95% chance true value falls within your stated value
What does it mean by Null Hypothesis?
How can we better studies?
- Increase sample size
- Use more representative sample group
- Eliminate user bias
- Ensure appropriate explanation of study
- Repar tests for validity
State 3 advantages and disadvantages of cohort studies
+ve
- Good for different outcomes
- Good for rare exposures
-ve
- Surveryor bias
- larger, more resiurces
- longer
What is a case control study?
What is a -ve?
Take patients witha condition, take patients without condition
Compare history
Make conclusions
Useful for rare conditions
But, cannot identify cause.
What are odds? How do we work our the odds of an event occuring?
Probability event will occur to probability of same eevnt not occuring
how likely an event is to happen compared to it not happening.
What is odds exposure? How do we work it out?
How do we interpet the value?
This measures likelihood of having been exposed to a particular factor among individuals with a certain condition compared to thise without the condition.
OE<1 - exposure is protective against condition
How do we interpretate OE?
What is Meta-analysis?
Combines results of multiple studies to get clearer overall picture
(2 or more primary studies, which address same hypothesis)
What is a systematic review?
Type of research that provides overview of all available primary studies on specific topic
