Figure 5.

Scatter diagrams and regression lines (95% CI) on correlations between the amount of HFNT hours per day and changes in exacerbations (A) and hospitalizations (B) mMRC dyspnea scale (C), difficulty of expectoration (VAS) (D), SGRQ total score (E) and SpO₂ at rest (F) FEV₁% (G), FVC% (H), and FEF_25–75% (I). r = Pearson coefficient, ρ = Spearman coefficient. Abbreviations: HFNT, high-flow nasal therapy; mMRC, modified medical research council; VAS, visual analog scale; SGRQ, Saint George Respiratory Questionnaire; SpO₂, peripheral blood oxygen saturation; FEV₁, forced expiratory volume in the first second; FVC, forced vital capacity; FEF_25–75, forced expiratory flow between 25% and 75% of FVC.