1. What is Relative Risk Reduction (RRR)?

Definition: RRR measures the proportion of risk reduction in the experimental group compared to the control group.

Purpose: It helps medical researchers and clinicians understand the effectiveness of a treatment or intervention.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( RRR \) — Relative Risk Reduction (percentage)
• \( CER \) — Control Event Rate (proportion between 0 and 1)
• \( EER \) — Experimental Event Rate (proportion between 0 and 1)

Explanation: The difference between CER and EER is divided by CER to show the proportional reduction in risk.

3. Importance of RRR Calculation

Details: RRR helps compare treatment effectiveness across studies with different baseline risks and is commonly used in clinical trials.

4. Using the Calculator

Tips: Enter CER and EER as proportions (e.g., 0.25 for 25%). CER must be greater than or equal to EER, and both must be between 0 and 1.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between RRR and ARR?
A: RRR shows proportional reduction, while Absolute Risk Reduction (ARR) shows the actual difference between CER and EER.

Q2: When is RRR most useful?
A: RRR is most useful when baseline risks vary between studies, allowing comparison of treatment effects.

Q3: What are typical CER and EER values?
A: These vary by study but are typically between 0.01 and 0.5 in medical research (1% to 50% event rates).

Q4: Can RRR be negative?
A: Yes, if EER > CER, it indicates the treatment may be harmful rather than beneficial.

Q5: How should I interpret a 50% RRR?
A: It means the treatment reduced the risk by 50% compared to the control group's risk.