2020 P2 Q86
Q1. What is the specificity of sputum microscopy in detection of Pulmonary Tuberculosis (PTB) as per the information given below?
| Sputum microscopy | PTB Present | PTB Absent | Total |
| --- | --- | --- | --- |
| Positive | 270 | 20 | 290 |
| Negative | 30 | 180 | 210 |
| Total | 300 | 200 | 500 |
- 10 %
- 36 %
- 90 %
- 94 %
Answer & explanation — reveal it in the interactive practice above.
PYQ 2020–2025 — page 60
2020 P2 Q97
Q2. Predictive accuracy of a screening test depends on the following EXCEPT:
- Disease prevalence
- Disease incidence
- Sensitivity of screening test
- Specificity of screening test
Answer & explanation — reveal it in the interactive practice above.
PYQ 2020–2025 — page 62
2024 P2 Q120
Q3. The table below shows the results of ELISA test for HIV infection:
| ELISA result | Infected | Noninfected |
| --- | --- | --- |
| Positive | 4900 | 950 |
| Negative | 100 | 94050 |
| Total | 5000 | 95000 |
Consider the following statements:
1. The sensitivity is 98%.
2. The specificity is 99%.
Which of the statements given is/are correct?
- 1 only
- 2 only
- Both 1 and 2
- Neither 1 nor 2
Answer & explanation — reveal it in the interactive practice above.
PYQ 2020–2025 — page 364
2025 P2 Q87
Q4. Given below is a table showing diagnosis of Myocardial infarction by ECG:
| ECG result | MI Present | MI Absent | Total |
| --- | --- | --- | --- |
| Positive | 45 (TP) | 8,000 (FP) | 8,045 |
| Negative | 5 (FN) | 32,000 (TN) | 32,005 |
| Total | 50 | 40,000 | 40,050 |
Consider the following statements:
I. Sensitivity is 90%.
II. Specificity is 80%.
Which of the statements given above is/are correct?
- I only
- II only
- Both I and II
- Neither I nor II
Answer & explanation — reveal it in the interactive practice above.
PYQ 2020–2025 — page 457
