Fig. 4

Self-assessed cough deficiency before and after initiation of MI-E therapy. Cough deficiency was assessed by a Numerical Rating Scale (NRS) ranging from 0 (no difficulty) to 10 (strongest difficulty). To enhance evaluability, groupings were made as follows: 0 = no cough deficiency, 1–3 = mild cough deficiency, 4–6 moderate cough deficiency, 7–10 = severe cough deficiency. The interval between baseline and follow-up visits was 6.2 months on average (SD = 5.7). n = 363.