A prevalence ratio less than 1.0 indicates which of the following?

• A. Condition is more prevalent in the numerator
• B. Condition is more prevalent in the denominator
• C. No association
• D. Both groups have equal prevalence

Answer: (B)

A prevalence ratio compares how common a condition is between two groups. It is the prevalence in the numerator group divided by the prevalence in the denominator group. If this ratio is less than 1.0, the numerator group has a lower prevalence than the denominator group, so the condition is more prevalent in the denominator group.

For example, if 10% of the numerator group have the condition and 20% of the denominator group do, the prevalence ratio is 0.5, reflecting higher prevalence in the denominator group. A ratio greater than 1 would mean the opposite, and a ratio of exactly 1 indicates equal prevalence.