Trans-oral approach N = 30 Trans-nasal approach N = 30 P
Histopathologic results of the second biopsy through direct laryngoscopy under general anesthesia n (%)
Squamous cell carcinoma 24 (80.0) 20 (66.7) < 0.001
Inflammatory cells 1 (3.3) 7 (23.3)
Dysplasia 4 (13.3) 2 (6.7)
Papilloma 1 (3.3) 1 (3.3)
Diagnostic test results
True positive 23 (76.7) 5 (16.7) < 0.001
True negative 5 (16.7) 10 (33.3)
False negative 1 (3.3) 14 (46.7)
False positive 1 (3.3) 1 (3.3)
Sensitivity 95.8% 26.3%
Specificity 83.3% 90.9%
Positive predictive value (PPV) 95.8% 83.3%
Negative predictive value (NPV) 83.3% 41.7%
Diagnostic accuracy 93.3% 50.0%