Cardiovascular disease and risk
Cardiovascular disease (CVD) includes diseases affecting the heart and blood vessels. Examples include coronary heart disease, stroke and congenital heart disease.
A risk factor is a factor associated with an increased likelihood of developing a disease.
Examples of cardiovascular risk factors considered in studies include:
- high blood pressure
- smoking
- stress
- diet
- genetic factors
- age and biological sex
Reading risk-factor data
Questions may present data comparing the level of a particular risk factor with a measure of CVD risk. The first task is to describe the pattern shown by the data without adding an unsupported explanation.
Identify the variables
Check what measure of exposure is being compared with the measure of cardiovascular risk.
Describe the trend
State whether risk generally increases, decreases or shows no clear pattern as the other variable changes.
Support with data
Use numerical values from the table or graph where these are available.
Worked example: A study investigated 523 non-smokers whose partners exposed them to different amounts of cigarette smoke.
The relative risk rises from 1.00 with no daily exposure to 1.23 with exposure to 1–19 cigarettes per day and 1.31 with exposure to 20 or more cigarettes per day.
Description: as smoke exposure increases, the reported relative risk of CVD also increases. The group exposed to at least 20 cigarettes per day has the highest relative risk.
Conclusion: the data show an association between greater exposure to cigarette smoke and greater CVD risk.
Exam Tip: When asked to describe cardiovascular data, give the direction of the trend and support it with figures. Save comments about reliability, confounding factors or causation for questions that ask you to evaluate or conclude.