1. What is Relative Risk?

Relative Risk (RR) is a statistical measure that compares the probability of an event occurring in an exposed group versus an unexposed group. It is commonly used in epidemiology and clinical research to assess the strength of association between exposure and outcome.

2. How Does the Calculator Work?

The calculator uses the Relative Risk formula:

Where:

• \( RR \) — Relative Risk (unitless)
• \( \text{Exposed Risk} \) — Event rate in exposed group (decimal)
• \( \text{Unexposed Risk} \) — Event rate in control group (decimal)

Interpretation:

• RR > 1: Increased risk in exposed group
• RR = 1: No difference in risk
• RR < 1: Decreased risk in exposed group

3. Importance of Relative Risk Calculation

Details: Relative Risk is crucial for understanding the magnitude of association between risk factors and outcomes in epidemiological studies, clinical trials, and public health research.

4. Using the Calculator

Tips: Enter both exposed and unexposed risks as decimal values (e.g., 0.15 for 15%). Unexposed risk must be greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between Relative Risk and Odds Ratio?
A: Relative Risk compares probabilities directly, while Odds Ratio compares odds. RR is generally more intuitive for risk interpretation.

Q2: When should I use Relative Risk?
A: Use RR in cohort studies and randomized controlled trials where you can calculate actual incidence rates.

Q3: What does an RR of 2.0 mean?
A: An RR of 2.0 means the exposed group has twice the risk of the outcome compared to the unexposed group.

Q4: Are there limitations to Relative Risk?
A: RR can be misleading when baseline risks are very low or very high, and it doesn't account for absolute risk differences.

Q5: How do I interpret RR confidence intervals?
A: If the 95% confidence interval includes 1.0, the result is not statistically significant at the 5% level.