Gender difference in the association between cough severity and quality of life among patients with postinfectious cough

Background: Despite close link exists between cough severity and quality of life (QoL), whether gender difference is implied in the effect of cough on QoL has not been studied yet. This study primarily aims to investigate whether the association between cough severity and QoL is modified by gender in patients with postinfectious cough.

Methods: Secondary analyses were performed in 180 participants with postinfectious cough in a multisite randomized controlled trial. Baseline demographics, clinical characteristics and score of cough specific quality of life questionnaire (CQLQ) were collected. Linear regression analyses were conducted to examine gender difference in CQLQ score and the association between cough severity and CQLQ score.

Results: Difference between women and men was not significant in CQLQ total score in the unadjusted analysis (P = 0.077). Women had a 2.20-point higher CQLQ total score than men (95% confidence interval (CI) 0.11-4.30; P = 0.039), after adjusting for age, cough duration, cough severity, and clinical center. Gender significantly modified the association between cough severity and CQLQ total score (coefficient 1.80, 95% CI 0.29-3.30; P = 0.020), after adjusting for age, cough duration, and study center. An increase of 1-point in cough severity was associated with a 2.55-point (95% CI 1.16-3.95) increase in CQLQ total score in women versus a 1.26-point (95% CI 0.20-2.31) increase in men (P = 0.020).

Conclusions: Female sex may be associated with worse QoL than men, and women's QoL may be more significantly impaired as cough symptom deteriorates. Gender difference should be taken into account in the clinical settings and research of cough and cough related QoL.

Trial registration: Chinese Clinical Trial Registry, ChiCTRTRC12002297. Registered 19 June 2012, http://www.chictr.org.cn/abouten.aspx .