Template:RCT risk increase example
From HandWiki
| Example of risk increase | |||
|---|---|---|---|
| Experimental group (E) | Control group (C) | Total | |
| Events (E) | EE = 75 | CE = 100 | 175 |
| Non-events (N) | EN = 75 | CN = 150 | 225 |
| Total subjects (S) | ES = EE + EN = 150 | CS = CE + CN = 250 | 400 |
| Event rate (ER) | EER = EE / ES = 0.5, or 50% | CER = CE / CS = 0.4, or 40% | |
| Equation | Variable | Abbr. | Value |
|---|---|---|---|
| EER − CER | absolute risk increase | ARI | 0.1, or 10% |
| (EER − CER) / CER | relative risk increase | RRI | 0.25, or 25% |
| 1 / (EER − CER) | number needed to harm | NNH | 10 |
| EER / CER | risk ratio | RR | 1.25 |
| (EE / EN) / (CE / CN) | odds ratio | OR | 1.5 |
| (EER − CER) / EER | attributable fraction among the exposed | AFe | 0.2 |
