Hazard Ratio

Definition

The hazard ratio (HR) or risk ratio is a measure of association used in survival analyses, comparing the instantaneous rate of occurrence of an event between two groups over time.

How it works

Hazard ratio differs from relative risk in that it takes into account the time until the event rather than simply its presence or absence.

Role

Evaluates the rate of occurrence of a disease over time by comparing two groups in longitudinal studies.

Examples

• An HR of 0.85 for mortality from all causes with adherence to a DASH diet
• An HR of 1.2 for breast cancer with high consumption of alcohol

Recommendations

Verify the assumption of proportional risks before interpreting the HR. Always consult Kaplan-Meier curves to visualize differences in survival. Consider adjusted HRs for relevant confounding factors.

Key takeaway

Hazard ratio compares instantaneous event rates over time, adapted for nutritional survival studies.

Related terms