INI-CET 1999

Question 1: A disease has three times more incidence in females as compared to males, with the same prevalence in both males and females. The TRUE statement is:

• A. Increase fatality in women (Correct Answer)
• B. More survival in women
• C. Less fatality in men
• D. Better prognosis in men

Explanation: ***Increase fatality in women*** - **Prevalence = Incidence × Duration of disease** - Given: Incidence in females = 3 × Incidence in males, but Prevalence is same in both - For males: Prevalence = I_m × D_m - For females: Prevalence = 3I_m × D_f - Since prevalences are equal: I_m × D_m = 3I_m × D_f - Therefore: **D_f = D_m/3** (females have 1/3 the disease duration of males) - **Shorter disease duration means worse survival and increased fatality in women** *More survival in women* - This would be incorrect because if women had better survival, their disease duration would be longer - With 3× higher incidence AND longer duration, the prevalence in women would be much higher than men, not equal - The equal prevalence despite higher incidence indicates women are dying faster (shorter duration) *Better prognosis in men* - While men do have longer disease duration (3× that of women), this option is vague - "Prognosis" could refer to recovery or survival, but the question specifically asks about the relationship between incidence and prevalence - The more precise statement is about increased fatality in women, which directly explains the epidemiological relationship *Less fatality in men* - This is essentially the same as saying "more survival in men" or "better prognosis in men" - While men do have less fatality (longer duration), the question stem focuses on the paradox of higher incidence in women with equal prevalence - The **key insight** is recognizing increased fatality in women, which is the direct answer to why higher incidence doesn't lead to higher prevalence