Which statement best describes absolute risk versus relative risk?

Which statement best describes absolute risk versus relative risk?

• A. Absolute risk is the probability of an event in a group; relative risk compares risk between groups.
• B. Absolute risk compares risk between groups; relative risk is the overall probability.
• C. Absolute risk is risk over time; relative risk is risk per unit population.
• D. Absolute risk is risk to staff; relative risk is risk to patients.

Answer: (A)

Absolute risk is the probability of an event occurring within a single group, expressed as a percentage. Relative risk, in contrast, compares that probability between two groups by forming a ratio. This distinction matters because absolute risk tells you the actual likelihood someone in that group will experience the event, while relative risk shows how much more or less likely the event is in one group compared with another. For example, if 2% of people in a treated group have the outcome and 1% in a control group have it, the absolute risks are 2% and 1%, and the relative risk is 2% ÷ 1% = 2.0, meaning the event is twice as likely in the treated group. Also, a large relative risk can occur even when the absolute difference is small if the baseline risk is low, so looking at both measures provides a fuller picture.

Absolute risk is the probability of an event occurring within a single group, expressed as a percentage. Relative risk, in contrast, compares that probability between two groups by forming a ratio. This distinction matters because absolute risk tells you the actual likelihood someone in that group will experience the event, while relative risk shows how much more or less likely the event is in one group compared with another. For example, if 2% of people in a treated group have the outcome and 1% in a control group have it, the absolute risks are 2% and 1%, and the relative risk is 2% ÷ 1% = 2.0, meaning the event is twice as likely in the treated group. Also, a large relative risk can occur even when the absolute difference is small if the baseline risk is low, so looking at both measures provides a fuller picture.