Summarizing categorical data

• A Proportion is a type of fraction in which the numerator is a subset of
  the denominator
  
  
  • proportion dead = 35/86 = 0.
  
  
  
  


• Odds are fractions where the numerator is not part of the denominator
  
  
  • Odds in favor of death = 35/51 = 0.
  
  
  
  


• A Ratio is a comparison of two numbers
  
  
  • ratio of dead: alive = 35: 51
  
  
  
  


• Odds ratio: commonly used in case-control study
  
  
  • Odds in favor of death for females = 12/25 = 0.
  
  
  • Odds in favor of death for males = 23/26 = 0.
  
  
  • Odds ratio = 0.88/0.48 = 1.