risk factors

• What is the difference between communicable and non-communicable diseases?

  Communicable diseases spread person to person
• Why couldn't scientists experiment on humans to find lung cancer causes?

  It would be unethical to do so
• What is the study of disease patterns to determine risk factors called?

  Epidemiology
• How did scientists link smoking to lung cancer?

  By studying lifestyle habits of individuals
• What correlation did scientists find between smoking and lung cancer?

  A positive correlation between smoking and lung cancer
• What does a positive correlation indicate?

  As one variable increases, so does the other
• What does correlation not prove?

  It does not prove causation
• What is a causal mechanism?

  A scientific explanation of how something occurs
• What are the harmful chemicals in cigarette smoke called?

  Carcinogens
• What did scientists conclude about smoking and lung cancer?

  Smoking increases the risk of lung cancer
• What is the potential problem with sampling in epidemiology?

  Samples may not represent the entire population
• Why is it important to take a large and random sample?

  To avoid bias in the results
• What can biased sampling lead to?

  Incorrect conclusions about the population