A psychosocial intervention for the management of functional dysphonia: complex intervention development and pilot randomised trial

BACKGROUND: Medically unexplained loss or alteration of voice—functional dysphonia—is the commonest presentation to speech and language therapists (SLTs). Besides the impact on personal and work life, functional dysphonia is also associated with increased levels of anxiety and depression and poor general health. Voice therapy delivered by SLTs improves voice but not these associated symptoms. The aims of this research were the systematic development of a complex intervention to improve the treatment of functional dysphonia, and the trialling of this intervention for feasibility and acceptability to SLTs and patients in a randomised pilot study METHODS: A theoretical model of medically unexplained symptoms (MUS) was elaborated through literature review and synthesis. This was initially applied as an assessment format in a series of patient interviews. Data from this stage and a small consecutive cohort study were used to design and refine a brief cognitive behavioural therapy (CBT) training intervention for a SLT. This was then implemented in an external pilot patient randomised trial where one SLT delivered standard voice therapy or voice therapy plus CBT to 74 patients. The primary outcomes were of the acceptability of the intervention to patients and the SLT, and the feasibility of changing the SLT’s clinical practice through a brief training. This was measured through monitoring treatment flow and through structured analysis of the content of intervention for treatment fidelity and inter-treatment contamination. RESULTS: As measured by treatment flow, the intervention was as acceptable as standard voice therapy to patients. Analysis of treatment content showed that the SLT was able to conduct a complex CBT formulation and deliver novel treatment strategies for fatigue, sleep, anxiety and depression in the majority of patients. On pre-post measures of voice and quality of life, patients in both treatment arms improved. CONCLUSION: These interventions were acceptable to patients. Emotional and psychosocial issues presented routinely in the study patient group and CBT techniques were used, deliberately and inadvertently, in both treatment arms. This CBT “contamination” of the voice therapy only arm reflects the chief limitation of the study: one therapist delivered both treatments. TRIAL REGISTRATION: Registered with the ISRCTN under the title: Training a Speech and Language Therapist in Cognitive Behavioural Therapy to treat Functional Dysphonia - A Randomised Controlled Trial. Trial Identifier: ISRCTN20582523 Registered 19/05/2010; retrospectively registered. http://www.isrctn.com/ISRCTN20582523