Risk Factors

• Non-communicable disease


  Diseases not spread from person to person, instead caused by risk factors
• Non-communicable disease


  • Lung cancer
• Epidemiology


  • Studying the patterns of disease to determine risk factors
• Cigarette smoking


  Increases risk of lung cancer
• Number of cigarettes smoked per day

  Positively correlated with risk of lung cancer
• Number of years smoked

  Positively correlated with risk of lung cancer
• Causal mechanism


  Scientific explanation for how a risk factor can cause a disease
• Carcinogens


  Chemicals in cigarette smoke that damage DNA and increase cancer risk
• Sampling


  • Investigating a disease by looking at a group of people rather than the entire population
• Sampling must be as large and random as possible to avoid bias