Data and Applications of Lifestyle Disease

Section 1 of 9Risk factors

Definition

• Definition A risk factor is something that increases the chance of a person developing a disease.

Lifestyle factors

• Lifestyle factors Diet, smoking, alcohol, exercise levels and obesity.
• These are linked to heart disease, type 2 diabetes, some cancers and liver disease.

Other factors

• Other factors Age, inherited genes and the environment also play a part; they are not all in our control.
• Some of these, such as age and inherited genes, cannot be changed, while lifestyle choices can be.

Multiple causes

• Multiple causes Most non-communicable diseases are caused by several factors that interact, so removing one factor lowers risk but may not remove it.

Section 2 of 9Correlation or cause?

1Pattern spotted

• Pattern spotted Data show that as one variable changes, the other changes too, for example higher body mass index and more cases of diabetes.

2Correlation only

• Correlation only A link does not prove that one factor causes the other, because a third factor could be responsible for both.

3Mechanism found

• Mechanism found A cause is accepted when scientists can explain how, and the effect appears in other studies.

Section 3 of 9Examples with evidence

Risk factor	Disease	Explanation
Obesity	Type 2 diabetes	Cells respond poorly to insulin
Smoking	Lung disease, cancer, heart disease	Tar and carcinogens damage cells and arteries
Alcohol	Liver disease	Liver cells are damaged by toxins
Saturated fat	Heart disease	Fatty deposits narrow the arteries

Section 4 of 9Reading data

1

Check the sample size: larger samples give more reliable results.

2

Check the sample is representative of the population, for example in age and sex.

3

Look for other factors that might explain the pattern.

4

Compare percentages or rates, not raw numbers, if group sizes differ.

5

State whether the evidence supports a link, then whether it shows a cause.

Section 5 of 9Worked example with data

Group	People studied	Cases of heart disease	Rate
Non-smokers	2000	100	5%
Smokers	500	75	15%
Conclusion			Smokers have three times the rate, so smoking is linked to heart disease

Section 6 of 9Costs of non-communicable disease

Impact

Human cost

• Human cost Reduced quality of life and early death, with strain on family members who become carers.

Financial cost

• Financial cost Treatment, medicines and lost working days for the health service and employers.

Prevention

• Prevention Education, healthy food and exercise programmes are cheaper than treatment.

Limits of prevention

• Limits of prevention Some people cannot change their risk, for example because of age or inherited genes, so treatment is still needed.

Section 7 of 9Reducing the risk

Individual choices

• Individual choices Stopping smoking, eating a balanced diet, taking regular exercise and drinking less alcohol each lower the chance of developing disease.

Government action

• Government action Public health campaigns, food labelling, taxes on tobacco and bans on smoking in public places encourage healthier behaviour.

Costs and benefits

• Costs and benefits Prevention costs money in advance, but it saves lives and reduces long-term treatment costs.

Section 8 of 9Key terms

Term	Meaning
Risk factor	A characteristic or behaviour that raises the likelihood of a disease.
Correlation	A relationship between two variables.
Causal link	A relationship where a change in one factor produces a change in another.
Non-communicable disease	A disease that cannot be passed from person to person.
Carcinogen	A substance that can cause cancer.
Representative sample	A group that reflects the make-up of the whole population being studied.

Section 9 of 9Exam technique

1

Stating that a correlation proves a cause.

2

Saying a risk factor means a person will definitely get the disease.

3

Ignoring sample size when judging evidence.

4

Thinking diseases such as cancer are always caused by a single factor.

5

Comparing raw numbers when the groups are different sizes.