1. EBM Appraisal (Diagnostics)

2. Clinical Scenario You are the duty resident at the traige on a Sunday afternoon when... a 3 year old Male came with a chief complaint of fever Px has been having intermittent fever for 3 weeks duration with associated non productive cough of 1 month Px has history of exposure at home to his grandmother who was non compliant with her 4 drug regimen for 8 months now

3. Clinical Question How accurate stool TB Xpert in diagnosing pulmonary tuberculosis in children in pediatric patients

4. PIOM P: Pediatric patients I: Stool TB Xpert O: Diagnosing PTB M: Cross-sectional study

5. Search Strategies Source of Database: Pubmed Keywords: Stool Xpert, Pulmonary TB Limits: Full Free Text

7. Question 1: Was the reference standard an acceptable one

8. The reference standard used was induced sputum TB culture

9. Question 2 Was the reference standard interpreted independently from the test in question

10. The researchers obtained from and processed test samples of all their subjects prior to classifiying them as having positive or negative TB. The study was also done in a prospective manner.

11. RESULTS

12. Question 1 What were the likelihood ratios of the various test results

13. SPUTUM CULTURE POSITIVE SPUTUM CULTURE NEGATIVE ROW TOTAL STOOL Xpert (+)819 STOOL Xpert (-)997106 TOTAL1798115 SENSITIVITY: 47% SPECIFICITY: 98.9% POSITIVE PREDICTIVE VALUE: 88.9% NEGATIVE PREDICTIVE VALUE: 91.5% POSITIVE LIKELIHOOD RATIO: 42.7 NEGATIVE LIKELIHOOD RATIO: 0.53

14. APPLICABILITY

15. Question 1 In our practice, is the test available? Affordable? Accurate? Precise?

16. Question 2 Can we generate a reasonable pre- test probability in our clinical scenario?

18. Question 2B Are the study patients similar to our own?

19. Question 3 Will the resultant post-test probabilities change our management?

20. THANK YOU