PH stuff you forget Flashcards
What is relative risk and attributable risk?
(hint, subtract has an A in it; and R/R)
Relative risk = incidence in exposed / incidence in unexposed
Attributable risk = incidence in exposed - incidence in unexposed
These 2 things can then be compared if one group have a placebo and one a drug. Relative risk of 2.27 means 127% increased risk of disease.
Absolute risk reduction is the same as absolute risk as long as the intervention reduces risk. NB it is still expressed as incidence (/no. of people or person years). For instance if 100 people treated and CVA prevented in 2.5 of them, ARR is 2.5/100.
What is NNT?
NNT = 1/absolute risk reduction
Hint NNT is ARR
If drug caused cumulative incidence to go from 10/1000 to 6/1000, absolute risk reduction is 4/1000. Relative risk reduction is 40%, relative risk is 0.6.
What is FeverPAIN score and what is output?
Screening tool to identify which people with sore throat have bacterial cause and likely to benefit from abx.
Fever (during past 24hrs)
Purulence (pus on tonsils)
Attend rapidly (within 3 days after onset of symptoms)
Inflamed tonsils
No cough or coryza
0 or 1 - No abx.
2 or 3 - consider delayed abx prescription
4 or 5 - consider immediate abx prescription (or back up)
Abx = 5-10 days phenoxymethylpenicillin qds. Clarithromycin if penicillin allergy.
What is equity/equality?
What is horizontal and vertical equity
Equity - what is fair and just
Equality - equal shares
Horizontal equity is like equality, equal Tx for equal need
Vertical equity is unequal Tx for unequal need (cold vs pneumonia).
3 domains of public health practice
Health improvement - societal interventions, aimed to preventing disease and promoting health and reducing inequalities.
Health protection - control infectious diseases/environmental hazards
Health care - organisation and delivery of safe services.
3 levels of public health interventions and an example
Individual level - e.g. childhood immunisation
Community level - e.g. playground for local community
Ecological level - e.g. clean air act (bans public smoking)
Describe health, illness and sick role behaviour
Health behaviour - prevent disease
Illness behaviour - seek remedy
Sick role - any activity aimed at getting well.
Why do we do health damaging behaviour?
Unrealistic optimism
1. Lack of personal experience with problem
2. Belief that preventable by personal action
3. Belief that if not happened by now, it’s not likely to
4. Belief that problem infrequent
Other reasons - health beliefs, situational rationality, culture variability, socioeconomic factors, stress, age
Difference between incidence and prevalence?
Incidence (AKA cumulative incidence, risk, incidence proprotion) - new cases per unit time, denominator = no. of disease free people at start of the study
Prevalence - existing cases, denominator is no. of people in population. No units.
What is person-time and what it is used to calculate?
Person time is total time from entry to study to:
- disease onset
- loss to follow-up
- end of study
Is used to calculate incidence rate (person time is denominator)
What is the difference between incidence rate and cumulative incidence (risk)
Cumulative incidence (risk) = No. of new cases in time period / no. of disease free people at start of time period
Incidence rate = no. of new cases in time period / total person time at risk during that time period.
Incidence rate is useful when participants are followed up for varying lengths of time.
What are the 2 broad groups of bias?
Selection bias (sampling or randomisation)
Information bias
If a relationship is not causal, name 4 things which could explain the trend?
Bias, chance, confounding, reverse causation
What is prevention paradox?
Population approaches make little difference to the individual.
It is why we sometimes use the high risk approach rather than the population approach to prevention.
Describe 4 reasons a person will change behaviour as part of health belief model
Believe they are susceptible to the condition in question (e.g. heart disease)
Believe that it has serious consequences
Believe that taking action reduces susceptibility
Believe that the benefits of taking action outweigh the costs
Cues to action (internal - MI, getting older; external - family death, what Dr tells you) and health motivation also involved.