1. What is Relative Risk Reduction?

Relative Risk Reduction (RRR) is a measure that shows how much the risk of an outcome is reduced in the treatment group compared to the control group. It's expressed as a percentage of the risk in the control group.

2. How Does the Calculator Work?

The calculator uses the RRR formula:

Where:

• \( CER \) — Control Event Rate (proportion of events in control group)
• \( TER \) — Treatment Event Rate (proportion of events in treatment group)

Explanation: RRR compares the difference in event rates between groups relative to the control group's event rate.

3. Importance of RRR Calculation

Details: RRR is important in clinical research to understand the effectiveness of treatments. It helps quantify how much a treatment reduces the risk of an adverse outcome compared to control.

4. Using the Calculator

Tips: Enter both CER and TER as proportions between 0 and 1 (e.g., for 25%, enter 0.25). The calculator will output RRR as a percentage.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between RRR and ARR?
A: RRR shows the proportional reduction in risk, while Absolute Risk Reduction (ARR) shows the simple difference in risk between groups.

Q2: When is RRR most useful?
A: RRR is particularly useful when baseline risks are low, as it can make treatment effects appear larger than they are in absolute terms.

Q3: What are limitations of RRR?
A: RRR doesn't account for baseline risk, so a large RRR might correspond to a small actual benefit if the baseline risk is very low.

Q4: How should RRR be interpreted?
A: RRR should always be considered alongside absolute risk measures to get a complete picture of treatment benefit.

Q5: Can RRR be negative?
A: Yes, a negative RRR indicates the treatment increased risk compared to control.