Calculation and Conversion of Effect Measures
Effect Measures for categorical/Time-to-Event »
1. Calculating a Single-Group Rate and Its Confidence Interval
- S1: Calculate Single-Group rate and Confidence inteval
- 10 methods are provided.
2. Calculating Odds Ratio, Relative Risk, or Rate Difference from a Contingency Table.
- Based on data from a 2x2 contingency table.
- Calculates Odds Ratio (OR), Relative Risk (RR), and Risk Difference (RD), and their corresponding Standard Error and Confidence Interval.
3. Conversion Between Odds Ratio (OR), Relative Risk (RR), and Hazard Ratio (HR)
3.1 Converting OR to RR
- Scenario 1: Event rate (P) in the non-exposed group is known.
- Scenario 2: Event rate (P) in the non-exposed group is unknown, but P > 10%.
- Scenario 3: Event rate (P) in the non-exposed group is unknown, but P < 10%
3.2 Converting HR to RR
- Scenario 1: Short follow-up time or very low event rate.
- Scenario 2: Event rate in the control group is known at the end of the follow-up period.
- Scenario 3: Unknown event rates, but event rates of both groups are estimated between [0.2, 0.8].
- Scenario 4: Unknown event rates, but event rates of both groups are estimated between [w, u].
4 Estimating Effect Measures for Survival Outcomes
4.1 Estimating HR and Confidence Interval from Survival Curves
- Provides software for data point extraction.
- Provides tutorial for the latest algorithm .
4.2 Estimating HR and Confidence Interval from Other Information
- Scenario 1: Calculate HR and confidence interval based on median survival time and number of event.
- Scenario 2: Calculate confidence interval of HR based on HR value and log-rank's p-value.
- Scenario 3: Calculate confidence interval of HR based on median survival time and log-rank's p-value.
- Scenario 4: Estimate approximate HR value based on number of event and follow-up time.
5. Other Types
5.1 Switch Reference Group
- If a study reports a relative comparison of A vs. B, while a meta-analysis requires the effect for B vs. A.