Changing etiological frequency of chronic cough in a tertiary hospital in Shanghai, China

Background: The frequency distributions of the etiologies of chronic cough have changed over time. This study aimed to investigate the changing etiological frequency of chronic cough in a tertiary hospital in Shanghai, China, and to explore the clinical significance. Methods: Medical records of 1,311 patients with chronic cough who visit our hospital between January 2009 and December 2016 were retrospectively reviewed. The etiologies of chronic cough were identified according to a standardized step-by-step diagnostic protocol and the changes in the etiological frequency of chronic cough over the years were using the Chi-squared (chi(2)) test. Results: Cough variant asthma (CVA) (449/1,311, 34.2%), gastroesophageal reflux-related chronic cough (GERC) (374/1,311, 28.5%), upper airway cough syndrome/postnasal drip syndrome (UACS/PNDs) (241/1,311, 18.4%), atopic cough (AC) (188/1,311, 14.3%), and non-asthmatic eosinophilic bronchitis (NAEB) (147/1,311, 11.2%) were the common causes of chronic cough in descending order. The post-infectious cough (PIC) (39/1,311, 3.0%) and angiotensin-converting enzyme inhibitor (ACED-induced cough (25/1,311, 1.9%) were less common. During the 8-year period, the proportion of CVA (chi(2) =72.86, P<0.0001) and UACS/PNDs (chi(2) =68.80, P<0.0001) decreased, while those of NAEB (chi(2 )=51.38, P<0.0001), GERC (chi(2) =55.95, P<0.0001) and AC (chi(2) =39.09, P<0.0001) increased. Conclusions: The etiological frequency of chronic cough varies over time, and it may encourage the adjustment of the current diagnostic and therapeutic strategies for chronic cough.