cohort

• • Cohort– study of 2 or more groups of individuals without the disease and differ in one main factor to see who develops particular disease over period of time
• +

  • Gather data regarding sequence of events; can assess causality
• +

  • Examine multiple outcomes for a given exposure
• +

  • Good for investigating rare exposures
• +

  • Can calculate rates of disease in exposed and unexposed individuals over time (e.g. incidence, relative risk)
• _

  • Large numbers of subjects are required to study rare exposures
  • Susceptible to selection bias