The control group showed a cough reflex at a capsaicin concentration of 2.61 μM (0.98-7.80), while patients with mild dysphagia did so at 7.28 μM (1.95-15.6), those with moderate dysphagia at 22.07 μM (15.6-62.5), and those with severe dysphagia at 71.75 μM (31.2-250). Control vs mild p < 0.01, control vs moderate p < 0.01, control vs severe p < 0.01, mild vs moderate p < 0.01, mild vs severe p < 0.01, moderate vs severe p < 0.05. There was a significant correlation between the grade of dysphagia and the threshold capsaicin concentration that provoked a cough reflex (ρ = -0.796, p < 0.001).