Internet-Based Behavioral Cough Suppression Therapy for Refractory Chronic Cough: A Randomized Controlled Trial

The purpose of this study was to assess the efficacy of internet-based behavioral cough suppression therapy (IBCST) and explore users' experiences.

This study involved a prospective, single-blind, randomized controlled trial comparing the efficacy of a 5-week IBCST and healthy lifestyle education control intervention in patients with refractory chronic cough. Additionally, qualitative interviews were conducted and analyzed using grounded theory methodology.

IBCST and the healthy lifestyle control included 5 weeks of asynchronous content delivered via video and text on a study-specific website. IBCST emphasized education and cough suppression.

The Leicester Cough Questionnaire (LCQ) and Cough Severity Visual Analog Scale (VAS) were the primary and secondary outcome measures, respectively, and were administered at baseline (T0), 1-week posttreatment (T1), and 1-month posttreatment (T2). Semistructured qualitative interviews were conducted with a subgroup of IBCST participants.

Thirty-nine adults with refractory chronic cough enrolled, and 30 (27 women, three men; M_age = 61 years) completed the study (18 IBCST, 12 control). IBCST resulted in clinically significant improvements for 72% of participants in LCQ total score at T1 with a mean change of 3.74 (p = .014, η_p² = .205) and 76% of participants at T2 with a mean change of 4.1 (p = .033, η_p² = .163). VAS changes did not reach the minimum clinically meaningful threshold but trended in that direction for the IBCST group at T1 (p = .056, η_p² = .128). Qualitative analysis revealed IBCST participants liked the convenience and quality of treatment and experienced improvements in symptom control.

IBCST was feasible and efficacious and resulted in total LCQ score changes on par with what has been reported for other BCST interventions, paving the way for adaptation to a digital therapeutic.