Environmental: air pollution, UV radiation, exposure to carcinogens (cancer-causing chemicals).
Genetic: inherited predisposition to some cancers, cardiovascular disease, diabetes.
Risk factors do not cause disease — they increase the probability. Correlation is not causation.
BMI (Body Mass Index) = mass (kg) ÷ height² (m²). BMI 18.5–24.9 = healthy. Over 30 = obese.
Evaluating data on risk factors
Correlation = two things appear related. Causation = one thing directly causes another.
Large sample sizes and repeatable studies increase confidence in findings.
Confounding variables must be controlled (e.g. a smoker who also eats poorly — which causes disease?)
AQA often asks you to evaluate a graph showing risk factor data — look at sample size, units, trend and anomalies.
Exam questions — 3 questions · 9 marks
⚡ Extended questions included. Read the hint. Write in full sentences. AI marks against the AQA mark scheme.
1 markRisk factor definitionAQA 8461 style
What is a risk factor?
A Something that directly causes a disease
B Something that is associated with an increased likelihood of developing a disease
C Something that can be inherited from parents
D Something that spreads a communicable disease
3 marksEvaluate risk factor dataAQA 8461 P1 style
A study shows that people who smoke have a higher rate of lung cancer. Explain why this does not prove that smoking causes lung cancer, and what evidence would strengthen the link. (3 marks)
Hint: Explain the correlation/causation distinction, name a confounding variable, then say what would make the evidence stronger.
+30 XP
3 marksBMI calculation and evaluationAQA 8461 P1 style
A person has a mass of 80 kg and a height of 1.75 m. Calculate their BMI and state whether they are in the healthy range. Evaluate one limitation of using BMI to assess health risk. (3 marks)
Hint: Show all working for BMI. State if healthy (18.5–24.9), overweight (25–29.9) or obese (30+). Then give a genuine limitation.