Association Between Nasal Endoscopic Features and PND
Secretions in posterior the nasal cavity were higher among the “rhinitis with PND” group compared to “rhinitis only” (78.3% vs 55.3%, P= 0.02). Redness of nasopharynx between “rhinitis with PND” compared to “rhinitis only” are as follows: none (10 vs 5.3%) , roof only, , (36.7 v 18.4) and diffuse redness ( (53.3% vs 76.3%) , P=0.02). There presence of hemorrhagic spots were similar between “rhinitis with PND” compared to “rhinitis only” (11.7 v 18.4, p=0.35). There is also no difference between group for granular posterior pharyngeal wall (63.3v 71.1, p=0.43).
The presence of secretions is 78.33% sensitive, 44.74% specific, 69.11% positive predictive value (PPV) and 56.67% negative predictive value (NPV), with a likelihood ratio positive 1.41 and likelihood ratio negative 0.48 to predict PND among rhinitis. This is calculated in the 2 by 2 table (Table 2).