Diagnostic accuracy of fractional exhaled nitric oxide for cough variant asthma in chronic cough patients: a meta-analysis

Abstract

Objective Cough variant asthma (CVA) is a common cause of chronic cough.This study is to evaluate the effectiveness and accuracy of fractional exhaled nitric oxide (FeNO) for diagnosing CVA among patients with chronic cough. Methods We searched the Embase, PubMed, Medline, Cochrane library, Web of science, Baidu scholar, Chinese National Knowledge Infrastructure (CNKI, in Chinese), and Wanfang (in Chinese) databases for articles published from inception to August 2016.Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) items were used for quality assessment of included studies.The Stata 14.0 and RevMan 5.0 softwares were adopted to perform the heterogeneity test and pooled the sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and the area under curve (AUC) of summary receiver operating characteristics (SROC) curve. Results There were 5 eligible studies, which included 704 participants in this meta-analysis.It was showed that the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and the AUC of SROC curve were 0.74[95% confidence interval (CI): 0.69-0.79], 0.85 (95% CI: 0.81-0.88), 4.73 (95% CI: 3.70-6.05), 0.31 (95% CI: 0.26-0.38), 14.84 (95% CI: 10.11-21.79) and 0.87 (95% CI: 0.84-0.89), respectively for CVA. Conclusions This meta-analysis suggests that FeNO has better sensitivity and specificity, and could be used as an important index of diagnosing CVA among patients with chronic cough. Key words: Fractional exhaled nitric oxide; Cough variant asthma; Chronic cough; Meta-analysis