Epidemiology & Biostatistics MCQs

Community Medicine (PSM) · 6 free questions with answers & explanations.

1. In a village of 10,000 people, 200 new cases of tuberculosis were diagnosed over one year. The total person-years of observation was 9,800. At the start of the year, 50 people already had TB. Which of the following best represents the incidence rate of TB in this village?
2. A study follows 500 healthy adults for 10 years to assess the development of hypertension. Of these, 100 develop hypertension during the study period. The prevalence of hypertension in the general population is known to be 20%. What type of study design is this, and what is the cumulative incidence of hypertension in this cohort?
3. A new rapid diagnostic test for dengue is evaluated against a gold-standard PCR test in 200 suspected cases. Results: True positive = 80, False positive = 10, False negative = 20, True negative = 90. What is the specificity of the new test?
4. In a randomized controlled trial comparing a new antihypertensive drug versus placebo, the incidence of stroke in the treatment group was 2% and in the placebo group was 5%. What is the Number Needed to Treat (NNT)?
5. A researcher states that the p-value in their study comparing two interventions is 0.03. Which of the following is the most accurate interpretation of this finding?
6. In an investigation of a food-borne outbreak at a wedding, the attack rate among those who ate biryani was 70% and among those who did not eat biryani was 10%. The Relative Risk of illness associated with eating biryani is: