Characteristics of adults with potential refractory chronic cough identified using an algorithm designed for administrative claims databases: A descriptive study.

As population-based studies describing the characteristics of patients with refractory chronic cough (RCC) are sparse, the objective of this descriptive study was to identify and describe such patients using an algorithm developed for administrative claims databases and requiring validation in future. We identified adults with chronic cough (N = 782,121) from Optum Clinformatics™ Data Mart as individuals with a 'cough event' (primary cough event; based on ICD codes/relevant prescriptions) and ≥2 cough events in the 56-180 preceding days. We applied several exclusion criteria to identify potential RCC cases and stratified them into probable, possible, and unlikely RCC cohorts by the number of cough events during 1-year follow up (≥3, 1-2 or 0 events, respectively).