HADPOP Flashcards
Inverse care law
Availibility of good medical care
Inversely proportional to population need
Routine surveillance
Ongoing systematic monitoring + collection of data on regular basis
To detect changes / trends in specific area
Ad-hoc samples
Samples collected in non-systematic manner
Based on covenience
Census
Simultaneous recording of demographic data
By govt, specific time
All individuals in area
Fecundity
Biological capacity to produce offspring
Fertility
actual reproductive performance
Chance
Unpredictable occurence of events
No deliberate influence
UK Notifiable diseases
Specific infectious diseases
Must report to public health authorities (LEGAL)
Verbal autopsies
Gathering info regarding persons death,
By speaking to family members
To reconstruct medical history
Cross Sectional Study
Research designb
Info from specific population
Specific time
Examine relationship between 2 variables
Correlation coefficient
How can we interpret the value?
Summary statistic
Strength of relationship between 2 variables
-1 to +1
-1: perfect negative correlation
+1: pefect positive correlation
Reservoir
Host in which pathogen can reside, replicate + transmit
Vector
Organism that transmits pathogen from infected host to susceptible host
Efficiency
Allocation of limited resources
To meet healthcare needs
Maximise outcomes
Equity
Fair distrobution of benefits within population
Health
Absence of disease
Health inequalities
Unfair variations in health
Health needs assesment
Systematic analysis of health needs of population to inform healthcare team
Placebo
Inert substance identical to active substance
Retrospective studies
Examine data from past records
Prospective studies
Collect data moving forward in real time
MORE COMPREHENSIVE EVALUATION OF OUTCOMES
State 3 advantages of routine data
- Readily available
- Cheap
- Establish baseline
State 3 disadvantages of routine data
Bias
Poorly presented
Delay between collection + publications
Give 7 examples of routine data
- Census
- Birth notification
- Birth registration
- Public health England
- Death certification]
- Death registration
Give 3 reasons why routine data is collected
- Clarify cause of death
- Pattern in mortality rates
- Identify health problems
What is the purpose of Bradford Hill’s Criteria?
What are the criteria?
Measure strength of evidence
+ Relationship between exposure + outome
- Specificity association
- Strength assocation
- Consistency of finding
- Biological plausibility
- Analogy
- Temporal sequence
- Dose response
- Reversibility
PNEUMONIC:
Sexy
Shaurya
Can’t
Be
Arsed
To
Do
Revision
What type of study is a survey?
Cross sectional study
State 2 purposes of surveys
- Measure outcome
- Measure risk factors
State two advantages of surveys
- Cheap, quick
- Clarifies population health needs
State two disadvantages of surveys
Cannot detect temporality
Bias (SELECTION BIAS)
What is incidence?
How do we work out the INCIDENCE RATE?
How do we work out incidence risk?
No. new events (NEW CASES IN DEFINDED POPULATION) in time period
no. new cases of disease in given time period / total pop at risk at same time period
no. new cases of disease in given time perioid / n. disease free persons at beginning of time period
What is prevalence?
Point prevalence?
No. cases of disease in given population at any set time
no. existing cases of condition at spepcifc time / total pop at specifc time
What is perioid prevalance?
No. ppl who were a case during any time during period as a proportion of otal number of ppl in population
How do we work out Relative Risk? i.e. Risk Ratio
How do we interpret the values?
Incidence Risk (in exposed) / incidence risk (in unexposed)
RR > 1 - Positive association
RR < 1 - Negative association
What are the 3 levels of prevention?
Primary - interventions designed to prevent onset of specific health condition (reduce incidence of disease by limiting risk factors), lifestyle changes, vaccines
Secondary - early intervention decreases impact of specific problem (reduce impact of disease that has already occured, catching it early, providing timely treatment)
Tertiary - treatment to improve quality of life + reduce symptoms of the disease after it has developed (minimise severity of disease)
What is the recommended max consumption of alcohol for men and women?
14 units
What is the formula used to calculate units?
Volume (ml) x ABV / 1000
CAGE QUESTIONAIRE
FAST alcohol screening test
How often have you had 8 or more units on one occasion in the past year?
Focuses on identifying high-risk drinking behavior.
AUDIT C
How to interpret the score?
Alcohol use disorders identification test - consumption
> 5: Audit C positive: increased risk of problem drinking
other 7 questions must be answered
> 5: lower risk
Non-random sampling
No random selection for participant selection. Instead, based on
1. Availibilty
2. Convenience
3. judgemental criteria
Random sampling
When participants are selected, each participant has equal chance of being selected
- Representative
- Unbiased
What are the 4 types of random sampling?
Simple - each member given identifier, no. selected at randopm
Stratified - divide population into strata (subgroups), select sample from each using random sampling
Cluser - natural clusters
Systematic sampling: every nth population member
What is a random error?
Variable perfomance due to chance alone
What is bias?
Systematic sampling error
Selection bias
Selection bias happens when the groups being studied are not chosen fairly or equally, leading to results that don’t accurately reflect the true situation.
Type of selection bias
- Sampling bias - sample not representative of population
- Non-response bias - People who respond to a survey differ significantly from those who do not.
How to minimise selection bias?
- Sampling bias - random sampling methods, ensure every membrane of population has equal chance of being included
- Non-response bias: Include a cover letter signed by a respected person to encourage participation.
Explain the importance and relevance of the survey to motivate respondents.
Information bias
AKA MEASUREMENT BIAS
Mistake when data is collected. Info gathered is not accurate
What are the two types of info bias
How can we reduce info bias
- Instrument bias: calibration
- Inter-observer: measurements of different interviewers - TRAINING
High accuracy, low precision
Random error
Low accurary, high precision
Systematic error
Validity
How accurate the measurement is in the study
Reliability
- Can the study’s results be reproduced consistently
Confounding variables
Extra variables that affect relationship between main variables being studied (independent + dependent), lead to incorrect conclusions, because they affect dependent and independent variables.
P value
Used to assess statistical significance of findings
Likelihood of obtaining observed results by chance aloe.
Effect size
Strength of observed relationship
Generalizability
Extent to which findings of study can be applied to larger population
What are the two methods of surveillance?
Passive
- Routine reporting of data from healthcare providers
- Voluntary repording of cases
(GIVES DATA ON NOTIFIABLE DISEASES)
Active
- Acticely searching for cases
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