Question

The most useful indicator for an acute illness is:

• A. Case fatality rate
• B. Standardized mortality ratio
• C. Cause-specific death rate
• D. Five-year survival rate

Hint:

Which rate uses the number of cases (not the whole population) as its denominator over a short period?

Answer 1

The Correct Option is A

Step 1: Define case fatality rate (CFR).
CFR is the proportion of diagnosed cases of a disease that die from it within a given period: \(CFR = \dfrac{\text{deaths from the disease}}{\text{number of diagnosed cases}} \times 100\). It measures the killing power or virulence of a disease over a short period.

Step 2: Match the indicator to acute illness.
Acute illnesses run a short course, so a measure that captures deaths among cases over a brief interval is most appropriate. CFR is therefore best suited to acute conditions and outbreaks (for example, an acute infection or food poisoning episode).

Step 3: Eliminate the others.
Standardized mortality ratio adjusts mortality for age and is a population-level comparison tool, not specific to acute disease severity.
Cause-specific death rate uses the whole population as the denominator and reflects population mortality burden, not the lethality among cases.
Five-year survival rate is designed for chronic diseases such as cancer, where prognosis is followed over years.

Step 4: Conclusion.
Case fatality rate is the most useful indicator for acute illness (option A). This matches the printed key.