The validity of clinical guidelines and nasal endoscopy in the diagnosis of chronic rhinosinusitis—a prospective observational study

Chronic rhinosinusitis is a common disease entity seen by ENT surgeons as well as general practitioners all over the world. This study is aimed to evaluate and validate whether the clinical guideline symptoms (set by AAO-HNS 2015) alone and/or nasal endoscopic findings can predict the diagnosis of CRS, taking CT as the gold standard. A total of 118 patients with symptoms of chronic rhinosinusitis were taken. They were divided into two groups on the basis of whether they fulfilled the Guideline symptom criteria laid down by AAO-HNS in 2015 for diagnosing chronic rhinosinusitis. Each group underwent diagnostic nasal endoscopy (DNE), and patients with either purulence, edema in the middle meatus or ethmoid, and polyps in the nasal cavity or middle meatus were considered positive for DNE. A Lund-Mackay CT score of > 4 was considered diagnostic of CRS. Each group was analyzed separately. Sensitivity, specificity, and positive predictive value of guideline symptom with and without the addition of nasal endoscopy was recorded taking CT as the gold standard. Nasal obstruction was the most common seen in all cases (100%) followed by headache in 45 (38.1%), facial pain in 32 (27.1%), anterior nasal discharge in 28 (23.7%), decreased sense of smell in 22 (18.6%), and posterior nasal discharge in 19 (16.1%). Two-thirds of patients (78, 66.1%) fulfilled the clinical guideline symptoms criteria, and one-third of patients (40, 33.9%) did not fulfill the clinical guideline symptoms criteria. A positive finding on DNE was found in 59.3% (n = 70) of patients. More than half of patients (62, 52.5%) had mild grade on endoscopic examination, while only 8 (6.8%) had moderate grade, and none had severe grade. Guideline symptoms have a high sensitivity (80%) but a low specificity (50.94%) in the diagnosis of CRS, with a fair level of agreement with CT diagnosis (Kappa = 0.32). DNE has a moderate sensitivity (72.31%) but a low specificity (56.60%) in the diagnosis of CRS, with a fair level of agreement with CT diagnosis (Kappa = 0.29). Sensitivity and specificity were 80.77% and 57.69% respectively when guideline symptoms and DNE findings are taken in series. We conclude that neither Guideline Symptom Criteria nor DNE is independently sufficient enough to have a high diagnostic accuracy for CRS. Comparing the diagnostic efficiency among various modalities, we report that in patients who meet guideline symptom criteria for CRS, the addition of nasal endoscopy turned out to be a cost-effective diagnostic approach and improves the diagnostic accuracy of DNE for CRS reasonably, hence should be emphasized as a diagnostic tool in the evaluation of patients for CRS.