The Role of Occupational Voice Demand and Patient-Rated Impairment in Predicting Voice Therapy Adherence

Abstract

Objective: Examine the relationship among the severity of patient-perceived voice impairment, perceptual dysphonia severity, occupational voice demand, and voice therapy adherence. Identify clinical predictors of increased risk for therapy nonadherence.

Methods: A retrospective cohort study of patients presenting with a chief complaint of persistent dysphonia at an interdisciplinary voice center was done. The Voice Handicap Index-10 (VHI-10) and the Voice-Related Quality of Life (V-RQOL) survey scores, clinician rating of dysphonia severity using the Grade score from the Grade, Roughness Breathiness, Asthenia, and Strain scale, occupational voice demand, and patient demographics were tested for associations with therapy adherence, defined as completion of the treatment plan. Classification and Regression Tree (CART) analysis was performed to establish thresholds for nonadherence risk.

Results: Of 166 patients evaluated, 111 were recommended for voice therapy. The therapy nonadherence rate was 56%. Occupational voice demand category, VHI-10, and V-RQOL scores were the only factors significantly correlated with therapy adherence (P < 0.0001, P = 0.018, and P = 0.008, respectively). CART analysis found that patients with low or no occupational voice demand are significantly more likely to be nonadherent with therapy than those with high occupational voice demand (P < 0.001). Furthermore, a VHI-10 score of ≤29 or a V-RQOL score of >40 is a significant cutoff point for predicting therapy nonadherence (P < 0.011 and P < 0.004, respectively).

Conclusion: Occupational voice demand and patient perception of impairment are significantly and independently correlated with therapy adherence. A VHI-10 score of ≤9 or a V-RQOL score of >40 is a significant cutoff point for predicting nonadherence risk.

Keywords: Adherence; Dysphonia; Occupational voice; Therapy dropout; Voice handicap.