Quiz 99, Module Cohort
Please calculate the incidence risk in the three exposure groups using the following data:
| Level of Exposure | Disease + | Disease - | Total |
|---|---|---|---|
| Low | 20 | 980 | 1000 |
| Medium | 30 | 620 | 650 |
| High | 24 | 226 | 250 |
| Unexposed | 120 | 7280 | 7400 |
none:
number of exposed cases pre 2-year time period
total number of exposed persons per 2-year time period
= low exposure group
= 20/1000 = 0.0200 (or 20 cases per 1,000 exposed per 2-yr time period))
Low-dose group
= 20/1000 = 0.0200 (or 20 cases per 1,000 exposed per 2-yr time period))
Medium exposure group
= 30/650 = 0.046
High exposure group
= 24/250 = 0.096
Unexposed group
= 120/7400 = 0.0162
Risk ratio calculations:
Relative risk in the low exposure group = 0.020/0.0162 = 1.23
Relative risk in the medium exposure group = 0.046/0.0162 = 2.84
Relative risk in the high exposure group = 0.096/0.0162 = 5.92
What is your conclusion with regard to dose-response relationship in these data?
