In a proportionate mortality rate, what is the denominator in the formula?

• A. The total number of deaths from all causes in the population during the study period
• B. The total number of deaths from all causes in the population
• C. The number of people in the population
• D. The incidence rate of the disease

Answer: (B)

Proportionate mortality rates express the share of deaths that are due to a specific cause within all deaths that occur in a population over a defined period. Because you’re forming a proportion, the denominator must be the total number of deaths from all causes in the population during that period. This lets the ratio reflect the actual portion of deaths attributable to that cause, rather than something like how many people live in the area or how often the disease occurs. The numerator would be the deaths from the specific cause of interest, and the denominator is not based on population size or incidence, but on all deaths.