Rehabilitation Treatment Specification System: Content and Criterion Validity Across Evidence-Based Voice Therapies for Muscle Tension Dysphonia

Systematically improving voice therapy outcomes is challenging as the clinician actions (i.e., active ingredients) responsible for improved patient functioning (i.e., targets) are relatively unknown. The theory-driven Rehabilitation Treatment Specification System (RTSS) and standard, voice-specific terminology based on the RTSS (RTSS-Voice) may help address this problem. This qualitative study evaluated if the RTSS and RTSS-Voice can describe four evidence-based voice therapies for muscle tension dysphonia without missing critical aspects (content validity) and identify commonalities and differences across them (criterion validity).