Block 1: Epidemiology
EPI4-2: THE ODDS RATIO (Continued)
  D+ D-  
E+ a c M1
E- b d M0
  N1 N0 T

The OR can also be worked out in another way if one was conducting the type of study which could follow up cohorts of exposed or unexposed people. This type of study design would make it possible to get population based estimates for the odds of getting a disease for the exposed and unexposed:

In this way,

The odds of diseased the exposed (ODE+) is given by

Similarly the odds of disease in the non-exposed (ODE-)

Hence




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General Introduction to Occupational Health: Occupational Hygiene, Epidemiology & Biostatistics by Prof Jonny Myers is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.5 South Africa License
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