Page 38 - PCC13

Odds
• 24 people skiing down a slope, and 6 fall • oddsofafall
= 6 falls/18 did not fall = 6/18 = 1/3 = 0.33
odds = number of events of interest number without the event
50 100
Example
Live No live
birth birth Total
Treatment
50
50
100
Control
40
60
100
• Risk ratio = • OddsRatio=
‐
= 5/4 = 1.25
=1 4=1.5 6
40 = 0.5 ‐ 0.4 = 0.1 =10% 100
40 100
50
50
40
60
50
100
• Abs Risk Diff =
38
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