View source for Template:RCT risk increase example


{| class="wikitable"
|-
! rowspan="2" style="visibility:hidden;" | &nbsp;
! colspan="3" style="border-right:2px solid grey" | Example of risk increase
|-
! Experimental group  (E)
! [[Scientific control|Control group]] (C)
! style="border-right:2px solid grey" | Total
|-
| Events (E)
| EE = 75
| CE = 100
| style="border-right:2px solid grey" | 175
|-
| Non-events (N)
| EN = 75
| CN = 150
| style="border-right:2px solid grey" | 225
|-
| Total subjects (S)
| ES = EE + EN = 150
| CS = CE + CN = 250
| style="border-right:2px solid grey" | 400
|-
| Event rate (ER)
| [[Experimental event rate|EER]] = EE / ES = 0.5, or 50%
| [[control event rate|CER]] = CE / CS = 0.4, or 40%
| style="border-right:2px solid grey" |
|}

{| class="wikitable"
! Equation || Variable || [[Abbreviation|Abbr.]] || Value
|-
|EER &minus; CER
| absolute risk increase || ARI || 0.1, or 10%
|-
|(EER &minus; CER) / CER
| relative risk increase || RRI || 0.25, or 25%
|-
|1 / (EER &minus; CER)
|[[Medicine:Number needed to harm|number needed to harm]]|| NNH || 10
|- 
| EER / CER ||[[Risk ratio|risk ratio]]|| RR || 1.25
|- 
| (EE / EN) / (CE / CN) ||[[Odds ratio|odds ratio]]|| OR || 1.5
|- 
| (EER &minus; CER) / EER ||[[Medicine:Attributable fraction among the exposed|attributable fraction among the exposed]]|| AF<sub>e</sub> || 0.2
|}