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Background
| Experimental Event Rate | = | EER | = | N of events in the experimental group / N of patients in the experimental group | |
| Control Event Rate | = | CER | = | N of events among controls / N of patients in the control group | |
| Experimental Event Odd | = | EEO | = | N of events in the experimental group / N of patients without the event | |
| Control Event Odd | = | CEO | = | N of events among controls / N of patients without event in the control group | |
| Relative Risk Reduction | = | RRR | = | (CER-EER)/CER | |
| Absolute Risk Reduction | = | ARR | = | CER-EER | If the end-point is a negative event and EER |
| Number Needed to benefit | = | NNTB | = | 1/ARR | |
| Relative Benefit Increase | = | RBI | = | (EER-CER)/CER | |
| Absolute Benefit Increase | = | ABI | = | EER-CER | If the end-point is a positive event and EER>CER |
| Number Needed to benefit | = | NNTB | = | 1/ABI | |
| Relative Risk Increase | = | RRI | = | (EER-CER)/CER | |
| Absolute Risk Increase | = | ARI | = | EER-CER | If the end-point is a negative event and EER>CER |
| Number Needed to Harm | = | NNH | = | 1/ARI | |
| Odds Ratio | = | OR | = | EEO/CEO | |
| Relative Risk (risk ratio) | = | RR | = | EER/CER | |