Cough Burden and Sleep Quality in Patients with Idiopathic Pulmonary Fibrosis Receiving Antifibrotic Therapy: A...

Background and Objectives: Idiopathic pulmonary fibrosis (IPF) is frequently accompanied by chronic cough, which may negatively affect sleep quality. However, the relationship between cough burden and sleep disturbances in patients undergoing antifibrotic therapy remains inadequately defined. This study aimed to investigate the association between cough and sleep quality in patients with IPF and to evaluate the potential effects of antifibrotic treatment on these outcomes. Materials and Methods: This cross-sectional analytical study was conducted at a tertiary care center in Türkiye between January 2019 and December 2024. Patients with a diagnosis of IPF who were receiving antifibrotic therapy (nintedanib or pirfenidone) were consecutively recruited from the pulmonology outpatient clinic. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI), and cough-related quality of life was evaluated with the Leicester Cough Questionnaire (LCQ). Pre-treatment data were obtained retrospectively based on patient recall, and follow-up assessments were conducted during ongoing therapy. Correlation analyses and multivariable linear regression models were used to identify factors associated with sleep quality. Results: The study included 74 patients, with a mean age of 68.6 ± 6.8 years. At baseline, 87.8% of patients had poor sleep quality (PSQI ≥ 5). During antifibrotic therapy, PSQI scores significantly improved (median 9 [IQR: 6-12] vs. 6 [IQR: 5-8], p < 0.001), accompanied by a clinically meaningful increase in LCQ total score (13.28 ± 2.86 vs. 16.06 ± 2.58, p < 0.001). Significant inverse correlations were observed between PSQI and LCQ scores at both baseline and follow-up. In multivariable analysis, LCQ score was an independent predictor of sleep quality during treatment (β = -0.453, p < 0.001), whereas demographic and physiological parameters showed no significant independent associations. No significant differences were detected between nintedanib and pirfenidone in terms of PSQI or LCQ outcomes. Conclusions: Cough-related quality of life is independently associated with sleep quality in patients with IPF receiving antifibrotic therapy. These findings highlight cough burden as a key determinant of patient-centered outcomes beyond traditional physiological measures. Targeted assessment and management of cough may represent an important strategy to improve sleep quality and overall quality of life in this population.