Predictive Value of Nasal Nitric Oxide for Diagnosing Eosinophilic Chronic Rhinosinusitis: A Systematic Review and Meta-Analysis

Objectives The primary aim of this study was to assess disparities in nasal nitric oxide (NO) levels between individuals diagnosed with eosinophilic chronic rhinosinusitis (ECRS) and those without ECRS. The second aim was to ascertain the comparative predictive efficacy of these nasal NO levels for the presence of ECRS. Methods A systematic analysis was conducted on relevant studies that compared nasal NO levels in individuals with ECRS and those without. Furthermore, the discriminatory capacity of nasal NO in distinguishing ECRS from non-ECRS cohorts was quantified. The risk of bias across studies was evaluated utilizing the Newcastle-Ottawa scale. Results The comprehensive review encompassed a total of 5 studies involving 470 participants. Findings revealed that patients diagnosed with ECRS exhibited significantly higher levels of nasal NO, as measured in parts per billion (ppb), compared to their non-ECRS patients. The mean difference was 130.03 ppb (95% confidence interval: [66.30, 193.75], I2 = 58.7%). The diagnostic odds ratio for nasal NO in identifying ECRS was 9.29 ([5.85, 14.75], I2 = 26.4%). The area under the summary receiver operating characteristic curve was 0.82. The correlation between sensitivity and false positive rate was 0.53, suggesting a lack of heterogeneity. Sensitivity, specificity, negative predictive value, and positive predictive value were 69% ([0.55, 0.79], I2 = 77.0%), 83% ([0.73, 0.90], I 2 = 68.5%), 77% ([0.69, 0.83], I 2 = 50.1%), and 75% ([0.67, 0.82], I 2 = 41.5%), respectively. Conclusion Nasal NO has the potential as a noninvasive diagnostic measure and endotype tool for ECRS.