Clinical impact and healthcare resource utilisation in patients with unexplained or refractory chronic cough: a French national population study

Background: The epidemiological, clinical and medico-economic burden of unexplained or refractory chronic cough (URCC) is poorly known. Objective: To describe sociodemographic characteristics, clinical impact, healthcare resource utilisation and associated costs in French patients with URCC. Methods: Populations of interest (chronic cough, URCC, controls) were identified from the general population-based Constances cohort (124 565 participants at the time of study inception) and invited to answer a specific ad hoc questionnaire on cough. Their healthcare resource utilisation data were extracted from the National Healthcare Database System. Results: Populations of interest were identified among participants for whom data and questionnaire responses were available (n=5277): URCC (n=116), non-URCC (n=1357) and no chronic cough (reference group; n=3804). The extrapolated frequencies of chronic cough and URCC in the Constances cohort were 3.8% and 0.22%, respectively. URCC was mainly associated with gastro-oesophageal reflux disease (31.0%) and asthma/COPD (18.3%). Depressive symptoms (Center for Epidemiological Studies Depression scale score ≥16) were significantly more frequent in patients with URCC than in controls (43.0% versus 24.0%, p=0.0036). Over the previous 12 months, the mean number of medical visits was higher in the URCC group than in controls (9.1 versus 6.0, p=0.0002). Treatment for underlying conditions of interest were also more frequent in the URCC group. Compared to controls, a 36% increase in medical visits and a four times increase in treatments of underlying conditions of interest were observed in the URCC group. Conclusions: URCC is associated with an important clinical impact and high healthcare resource utilisation and associated costs. The burden of URCC is significant and remains an unmet medical need.