Here are all the questions with their options and correct answers from

Here are all the questions with their options and correct answers from your screenshots. --- Q1. All about incidence are false except: A. Not affected by duration B. More than prevalence C. Measures old and new cases D. Used for chronic conditions (lung, liver) ✅ Correct Answer: A. Not affected by duration --- Q2. Incidence is best studied by: A. Retrospective studies B. Prospective studies C. Cross-sectional D. Case-control ✅ Correct Answer: B. Prospective studies --- Q3. In a population of 5000, number of new cases of TB is 500; old cases in the same population are 150. What is the prevalence of TB? A. 9% B. 12% C. 13% D. 18% ✅ Correct Answer: C. 13% --- Q4. Prevalence is a: A. Rate B. Ratio C. Proportion D. Mean ✅ Correct Answer: C. Proportion --- Q5. Which of the following can cause increase in prevalence of the disease? A. Immigration of healthy persons B. Increased cure rate C. Longer duration of illness D. Migration of diseased persons ✅ Correct Answer: C. Longer duration of illness --- Q6. Following is true about prevalence and incidence: A. Both are rates B. Prevalence is a rate but incidence is not C. Incidence is a rate but prevalence is not D. Both are not rates ✅ Correct Answer: C. Incidence is a rate but prevalence is not --- Q7. Proportional mortality rate is: A. Rate B. Ratio C. Proportion D. None ✅ Correct Answer: C. Proportion --- Q8. Epidemiology is distribution and determinants of ______ events. A. Political B. Health-related C. Social D. Personal ✅ Correct Answer: B. Health-related --- Q9. Odds ratio is indirect estimate of: A. Relative risk B. Prevalence rate C. Attributable risk D. Incidence rate ✅ Correct Answer: A. Relative risk --- Q10. Crude death rate is the simplest measure of mortality because it includes: A. Total population B. Mid-year population C. Live births only D. Preterm births also ✅ Correct Answer: B. Mid-year population --- Q11. Relative risk = A. Probability of event in control group ÷ Probability of event in treatment group B. Probability of event in treatment group ÷ Probability of event in control group C. Probability of event in treatment group ÷ Probability of event in treatment & control group D. Probability of event in treatment and control group ÷ Probability of event in control group ✅ Correct Answer: B. Probability of event in treatment group ÷ Probability of event in control group --- Q12. Bhopal gas tragedy is an example of: A. Point source epidemic B. Continuous epidemic C. Propagated epidemic D. Slow epidemic ✅ Correct Answer: A. Point source epidemic --- Q13. Case-control study estimates: A. Only Odds Ratio B. Odds Ratio and Attributable Risk C. Relative Risk, Attributable Risk, Population Attributable Risk D. Incidence, Relative Risk and Attributable Risk ✅ Correct Answer: A. Only Odds Ratio --- Q14. Distribution is: A. Frequency of health events B. Pattern of health events C. Frequency and pattern of health events D. Absence of health events ✅ Correct Answer: C. Frequency and pattern of health events --- Q15. In a study to establish smoking as a risk factor for a disease, 30 out of 50 smokers had the disease while 10 out of 50 non-smokers had the disease. Odds ratio is: A. 3 B. 6 C. 5 D. 10 ✅ Correct Answer: B. 6 --- Q16. Relative risk is calculated in: A. Cross-sectional study B. Cohort study C. Case-control study D. None ✅ Correct Answer: B. Cohort study --- Q17. Attributable risk means: A. Fatality of a disease B. Disease risk ratio between exposed and non-exposed C. Risk difference between exposed and non-exposed D. Communicability of a disease ✅ Correct Answer: C. Risk difference between exposed and non-exposed --- Q18. Relative risk of a disease measures: A. Strength of association B. Temporal relation C. Biological plausibility D. Specificity of association ✅ Correct Answer: A. Strength of association --- Q19. Secular trend means: A. Seasonal change B. Short-term change C. Long-term change D. Periodical change ✅ Correct Answer: C. Long-term change --- Q20. Maximum power of destruction of a disease is measured by: A. Survival rate B. Case fatality rate C. Specific death rate D. Proportional mortality rate ✅ Correct Answer: B. Case fatality rate --- Q17 (Pharmacology) Antagonist drug has: A. Efficacy B. Affinity C. Both of the above D. None of the above ✅ Correct Answer: B. Affinity.. correct the wrong answers

Here is a review of all the questions. Most answers are correct, but a few need fixing:

Questions with CORRECT answers (no change needed):

Q1 ✅ A - Incidence is not affected by duration (unlike prevalence) Q2 ✅ B - Prospective/cohort studies measure incidence Q3 ✅ C - (500+150)/5000 = 650/5000 = 13% Q4 ✅ C - Prevalence is a proportion (numerator is subset of denominator, no time dimension) Q5 ✅ C - Longer duration keeps cases in the pool longer, raising prevalence Q6 ✅ C - Incidence has a time dimension (per year) = rate; prevalence does not = proportion Q7 ✅ C - Proportional mortality rate is a proportion (deaths from cause / total deaths) Q8 ✅ B - Epidemiology is the study of distribution and determinants of health-related events Q9 ✅ A - Odds ratio is an indirect estimate of relative risk (used in case-control studies) Q10 ✅ B - Crude death rate = deaths / mid-year population × 1000 Q11 ✅ B - RR = risk in exposed (treatment) group ÷ risk in unexposed (control) group Q12 ✅ A - Bhopal gas tragedy was a single point-source exposure Q14 ✅ C - Distribution = frequency AND pattern of health events Q16 ✅ B - Relative risk is directly calculated in cohort studies Q17 ✅ C - Attributable risk = risk difference (exposed minus unexposed) Q18 ✅ A - Relative risk measures strength of association Q19 ✅ C - Secular trend = long-term change over years/decades Q20 ✅ B - Case fatality rate measures the killing power of a disease

Questions with WRONG answers (corrections below):

Q13 - WRONG. Correction:

Case-control study estimates: A. Only Odds Ratio is marked correct, but the better answer is B. Odds Ratio and Attributable Risk.

Case-control studies can calculate:

Odds ratio (directly)
Population attributable risk percent (using OR and exposure prevalence)

However, they cannot calculate true incidence, relative risk, or absolute attributable risk directly. In most standard exam keys (Park's Textbook of Preventive & Social Medicine), the accepted answer is A - Only Odds Ratio, because absolute attributable risk requires incidence data which case-control studies cannot provide. The marked answer A is actually correct for strict exam purposes.

Q15 - Calculation check:

Smokers with disease: 30 out of 50 → without disease: 20
Non-smokers with disease: 10 out of 50 → without disease: 40

Odds ratio = (30 × 40) / (20 × 10) = 1200 / 200 = 6 ✅

Marked answer B = 6 is correct.

Q17 Pharmacology - CORRECT:

An antagonist has affinity (it binds the receptor) but zero intrinsic efficacy (it produces no effect). Answer B. Affinity is correct. ✅

A pure antagonist occupies the receptor without activating it - it has affinity but no efficacy. This distinguishes it from an agonist, which has both affinity and efficacy.

Summary of actual errors found:

Q	Issue	Correction
Q6	Minor nuance: "Incidence is a rate" - technically incidence rate is a rate, but incidence proportion (cumulative incidence) is not. In standard PSM exams, C is accepted.	No change needed for exam purposes
Q13	Marked answer A is correct for strict interpretation	No change needed
Q17 Pharmacology	Already correct - B (Affinity) is right	No correction needed

All 20 epidemiology answers and the pharmacology question are correctly keyed. There are no wrong answers to correct in this set.

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