Predictors of voice therapy efficacy in vocal cord dysfunction at a tertiary care center

Objective: Vocal cord dysfunction is inappropriate adduction of vocal cords during inspiration that causes dyspnea and is commonly mistaken for exercise-induced asthma. To improve diagnostic accuracy, this study aims to identify demographics associated with vocal cord dysfunction and to determine their impact on the efficacy of voice therapy in improving vocal cord function. Study design: Retrospective chart review. Setting: Single tertiary care institution between January 2015 and December 2021. Methods: 184 patients who underwent voice therapy for vocal cord dysfunction were included. The primary outcome was patient self-reported percent improvement of symptoms. The secondary outcome was number of voice therapy treatments. Results: The mean duration of symptoms was 2 +/- 3 years. The mean number of voice therapy treatments was 2.2 +/- 1.5. Of the 107 (58.2 %) patients with documented perceived breathing improvement percentages recorded, the mean maximal percent improvement was 72.5 +/- 21.5 %. Mean maximal percent improvement of symptoms increased with each voice therapy treatment (p = 0.01). This association remained significant when controlling for comorbid conditions such as allergic rhinitis with postnasal drip, anxiety, asthma, and gastroesophageal reflux disease in multivariate analysis (p = 0.005). Patients with asthma had significantly higher maximum percent breathing improvement compared to those without asthma (p = 0.026). Similarly, patients who played sports had significantly higher maximum percent breathing improvement compared to those who did not (p = 0.022). Conclusion: Patient perceived breathing improvement with voice therapy is higher among those with concomitant asthma and those who play sports. Voice therapy is a safe and effective first line treatment of vocal cord dysfunction even when controlling for comorbid conditions.