Cognitive bias modification for social anxiety in adults who stutter: a feasibility study of a randomised controlled trial

Objective: To determine the feasibility and acceptability of a computerised treatment for social anxiety disorder for adults who stutter including identification of recruitment, retention and completion rates, large cost drivers and selection of most appropriate outcome measure(s) to inform the design of a future definitive trial. Design: Two-group parallel design (treatment vs placebo), double-blinded feasibility study. Participants: 31 adults who stutter. Intervention: Attention training via an online probe detection task in which the stimuli were images of faces displaying neutral and disgusted expressions. Main outcome measures Psychological measures: Structured Clinical Interview Global Assessment of Functioning score; Liebowitz Social Anxiety Scale; Social Phobia and Anxiety Inventory; State-Trait Anxiety Inventory; Unhelpful Thoughts and Beliefs about Stuttering. Speech fluency: percent syllables stuttered. Economic evaluation: resource use questionnaire; EuroQol three-dimension questionnaire. Acceptability: Likert Scale questionnaire of experience of trial, acceptability of the intervention and randomisation procedure. Results: Feasibility of recruitment strategy was demonstrated. Participant feedback indicated that the intervention and definitive trial, including randomisation, would be acceptable to adults who stutter. Of the 31 participants who were randomised, 25 provided data at all three data collection points. Conclusions: The feasibility study informed components of the intervention. Modifications to the design are needed before a definitive trial can be undertaken. Trial registration number I SRCTN55065978