Epidemiology Of Coronary Heart Disease Flashcards
What is coronary heart disease?
Type of heart disease which develops when the heart arteries cannot deliver oxygen-rich blood to the muscles.
What are the fixed risk factors for coronary artery disease?
Age
Male sex
Positive family history
What are the modifiable risk factors for coronary heart disease?
Hyperlipidaemia
Cigarette smoking
Hypertension
Diabetes Mellitus
Obesity
Alcohol
What is a risk?
Probability of an event happening calculated based on:
Risk ratio
Odds ratio
Risk difference
How is relative risk calculated?
Risk in the exposed group/ Risk in the control
This tells us how much a risk has changed from initial risk, and is typically used in cohort studies.
How is odds ratio calculated?
Odds ratio is calculated as:
Odds of event occurring in exposed group x odds not occurring in control/
Odds of event occurring in control x odds not occurring in control
It is used in case control studies and is considered as an approximate (similar) to relative risk in certain situations.
How can odds ratio approximate the relative risk?
Odds ratio is considered to be an approximate to the relative risk when:
—> the disease is rare
—> the cases of disease are from the same population as the control.
It cannot be used as an approximate when there is a high initial risk.
What is attributable risk?
It is the risk difference which provides information about the rates of a disease due only to the exposure.
Disease in the exposed group SUBTRACTED by the Disease in the control group
What is population attributable risk?
Using the background data for disease in a population to determine the risk of disease in population due to an exposure, which is used by practitioners for resource allocation to assess the impact of an intervention
Risk of disease in general population - risk of disease in the unexposed
Unexposed people with disease provides information about the background risk of disease.
What is the population attributable fraction?
Risk in general population - risk in unexposed/ risk in general population
What is the prevention paradox?
A preventative strategy will bring large benefits to the population but not to individuals
What is primary prevention?
Strategy to stop disease occurring by addressing the causes and risk factors in at-risk populations.
What is secondary prevention?
Focused on early detection of disease to provide intervention and treatment.
What are high risk strategies?
Primary prevention targeted to high risk populations. It is beneficial because:
—> It is tailored to the individual
—> patients and clinicians are more likely to be motivated
—> it is cost-effective, with a high relative risk ratio.
What are the drawbacks of high risk strategies?
It is hard to identify who is at risk
Most cases of disease are from low risk population
Limited potential
Does not always address underlying cause of disease
What is the population approach?
Primary prevention of disease in the general population.
This is beneficial because:
—> it has a large potenital for change
—>can achieve health equity
—> behavioural changes are more likely to occur due to peers and society.
What are the drawbacks of a population approach?
It requires multi-agency action
Prevention paradox with little benefit to individuals
Poor motivation
Benefit risk ratio is low
What is a high risk strategy for cardiovascular disease?
Hypertension medication
Exercise referral programmes
Dietary plans
What is a population strategy for cardiovascular disease?
Smoking bans
Sugar tax
How to find absolute risk reduction?
Risk in control group SUBTRACTED by risk in exposed group
What is number needed to harm?
The number of patients treated so that one experiences an adverse event.
1/attributable risk or 1/ (risk in exposed-risk in control)
What is number needed to treat?
Number of patients needed to treat to prevent a bad health outcome, which is used to assess the effectiveness of a clinical intervention.
1/Absolute risk reduction or 1/(risk in control/risk in exposed)
