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 control group's risk.

2. How Does the Calculator Work?

The calculator uses the RRR formula:

Where:

• \( Control\ Rate \) — Event rate in control group (0 to 1)
• \( Treatment\ Rate \) — Event rate in treatment group (0 to 1)

Explanation: The formula calculates the proportional reduction in risk between the two groups.

3. Importance of RRR Calculation

Details: RRR is important in clinical trials and medical research to understand the effectiveness of treatments. It helps compare the relative benefit between different interventions.

4. Using the Calculator

Tips: Enter both rates as values between 0 and 1 (e.g., 0.25 for 25%). The control rate must be greater than 0.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between RRR and absolute risk reduction?
A: RRR shows the proportional reduction in risk, while absolute risk reduction shows the actual difference in risk between groups.

Q2: Can RRR be negative?
A: Yes, a negative RRR indicates the treatment increased risk compared to control.

Q3: What's a good RRR value?
A: Higher positive values are better, but interpretation depends on context. Even small RRRs can be important for common serious conditions.

Q4: How does RRR relate to NNT (Number Needed to Treat)?
A: NNT is calculated from absolute risk reduction (1/ARR), while RRR gives the proportional benefit.

Q5: When should I use RRR vs other measures?
A: RRR is useful for understanding relative treatment effects, but should often be reported alongside absolute measures for full context.