Relative risk
The ratio of the risk (or probability) of an event for one group to the risk of the same event for a second group.
Example
The following data were collected on a random sample of students enrolled in a Statistics course at the University of Auckland.
| Attendance | ||||
| Regular | Not regular | Total | ||
| Course result |
Pass Fail |
83 17 |
19 27 |
102 44 |
| Total | 100 | 46 | 146 |
The risk of failing for students with non-regular attendance = 27/46 = 0.5870
The risk of failing for students with regular attendance = 17/100 = 0.17
The relative risk of failing for students with non-regular attendance compared to those with regular attendance = 0.5870/0.17 = 3.5
This can be interpreted as the risk of failing for students with non-regular attendance is about 3.5 times the risk of failing for students with regular attendance.
Curriculum achievement objectives references
Probability: Levels 7, (8)