1. What is Relative Risk?

Relative Risk (RR) is a measure used in epidemiology to compare the risk of a health event between two groups. It represents the ratio of the probability of the event occurring in the exposed group versus the unexposed group.

2. How Does the Calculator Work?

The calculator uses the Relative Risk formula:

Where:

• \( P1 \) — Risk in exposed group (0-1)
• \( P2 \) — Risk in unexposed group (0-1)

Explanation: The formula calculates how many times more likely the event is to occur in the exposed group compared to the unexposed group.

3. Importance of Relative Risk Calculation

Details: Relative Risk is crucial in medical research and public health for assessing the strength of association between exposure and outcome, helping to identify risk factors and guide preventive measures.

4. Using the Calculator

Tips: Enter risks as proportions between 0 and 1. Both values must be valid (0 ≤ P1 ≤ 1, 0 < P2 ≤ 1). P2 cannot be zero.

5. Frequently Asked Questions (FAQ)

Q1: What does a Relative Risk of 1 mean?
A: A Relative Risk of 1 indicates no difference in risk between the exposed and unexposed groups.

Q2: What is considered a significant Relative Risk?
A: Typically, RR > 1.5 or < 0.67 may be considered clinically significant, but this depends on the context and confidence intervals.

Q3: How is Relative Risk different from Odds Ratio?
A: Relative Risk compares probabilities directly, while Odds Ratio compares odds. RR is generally more intuitive but requires prospective study designs.

Q4: When should Relative Risk not be used?
A: RR may not be appropriate for case-control studies or when the outcome is very common (>10%) in the population.

Q5: How should Relative Risk be interpreted?
A: RR > 1 indicates increased risk in exposed group, RR < 1 indicates decreased risk, and RR = 1 indicates no difference.