The effect of two speech and language approaches on speech problems in people with Parkinson’s disease: the PD COMM RCT

Background Speech impairments are common with Parkinson’s disease (reported prevalence 68%), increasing conversational demands, reliance on family and social withdrawal. Objective(s) The PD COMM trial compared the clinical and cost-effectiveness of two speech and language therapy approaches: Lee Silverman Voice Treatment LOUD and National Health Service speech and language therapy for the treatment of speech or voice problems in people with Parkinson’s disease to no speech and language therapy (control) and against each other. Design PD COMM is a phase III, multicentre, three-arm, unblinded, randomised controlled trial. Participants were randomised in a 1 : 1 : 1 ratio to control, National Health Service speech and language therapy or Lee Silverman Voice Treatment LOUD via a central computer-generated programme, using a minimisation procedure with a random element, to ensure allocation concealment. Mixed-methods process and health economic evaluations were conducted. Setting United Kingdom outpatient and home settings. Participants People with idiopathic Parkinson’s disease, with self-reported or carer-reported speech or voice problems. We excluded people with dementia, laryngeal pathology and those within 24 months of previous speech and language therapy. Interventions The Lee Silverman Voice Treatment LOUD intervention included maximum effort drills and high-effort speech production tasks delivered over four 50-minute therapist-led personalised sessions per week, for 4 weeks with prescribed daily home practice. National Health Service speech and language therapy content and dosage reflected local non-Lee Silverman Voice Treatment speech and language therapy practices, usually 1 hour, once weekly, for 6 weeks. Trained, experienced speech and language therapists or assistants provided interventions. The control was no speech and language therapy until the trial was completed. Main outcome measures Primary outcome: Voice Handicap Index total score at 3 months. Secondary outcomes: Voice Handicap Index subscales, Parkinson’s Disease Questionnaire-39; Questionnaire on Acquired Speech Disorders; EuroQol-5D-5L; ICEpop Capabilities Measure for Older Adults; Parkinson’s Disease Questionnaire – Carers; resource utilisation; and adverse events. Assessments were completed pre-randomisation and at 3, 6 and 12 months post randomisation. Results Three hundred and eighty-eight participants were randomised to Lee Silverman Voice Treatment LOUD (n = 130), National Health Service speech and language therapy (n = 129) and control (n = 129). The impact of voice problems at 3 months after randomisation was lower for Lee Silverman Voice Treatment LOUD participants than control [−8.0 (99% confidence interval: −13.3, −2.6); p = 0.001]. There was no evidence of improvement for those with access to National Health Service speech and language therapy when compared to control [1.7 (99% confidence interval: −3.8, 7.1); p = 0.4]. Participants randomised to Lee Silverman Voice Treatment LOUD reported a lower impact of their voice problems than participants randomised to National Health Service speech and language therapy [99% confidence interval: −9.6 (−14.9, −4.4); p 70 years); disease severity measured using the Hoehn and Yahr staging (1.0–2.5, 3.0–5.0) and severity of speech measured using the Voice Handicap Index (VHI) total score (≤ 33, mild 34–44, moderate 45–61, severe > 61). To avoid any possibility of the treatment allocation becoming predictable, a random element was included within the randomisation process. Once the participant was randomised into the trial, they were given a unique trial identifier and the treatment allocation was confirmed by e-mail to the site. The primary outcome measure for the trial was patient-reported VHI total score at 3 months. The VHI measures the psychosocial consequences of voice disorders and provides an overall perception of effectiveness of voice-related communication. The VHI comprises of 30 questions (0–120 negatively scored) divided into emotional, functional and physical subscales (0–40 subscale score). Secondary outcomes were: the VHI subscales; the Parkinson’s Disease Questionnaire-39, a validated, health-related quality-of-life measure specific to PD; the Questionnaire on Acquired Speech Disorders, self-reported participation restriction related to speech and communication; the participant-rated EuroQol5D (5-level version) which provides a simple descriptive profile and a single index value for health status; the ICEpop Capabilities Measure for Older Adults (ICECAP-O), a measure of capability in older people for use in economic evaluations; a disease-specific participant resource usage questionnaire; carer quality of life, measured using the PD Questionnaire – carer; and adverse events. For participants in either SLT arm, any vocal strain or abuse believed to be associated with treatment was identified by the therapists at the participants’ SLT session and was reported in the adverse event log. All participant-reported resource usage forms completed for the trial were checked to ensure that no vocal strain or abuse had occurred in outpatient appointments with ENT specialists. At the 12-month clinical visit, the medical professional also checked whether any adverse events had occurred since entering the trial. There were two nested studies within this trial: a process evaluation and an economic evaluation. A process evaluation of the content of the interventions examined participants’ and therapists’ reported content of a subset of the two SLT interventions. Individual participant therapy data recorded by participants and therapists during the PD COMM trial were extracted from treatment record forms and therapy notes. Extraction category headings were piloted and reflected the Template for Intervention Description and Replication intervention reporting guidelines, with ongoing refinement as extraction progressed and components of the interventions were identified which were inadequately accounted for in the initial framework. The process evaluation of the implementation of the interventions used normalisation process theory which is highly attuned to the challenges of complex interventions as it encourages looking at systems as a whole. We considered that its conceptual framework would assist the interpretation and synthesis of data and analysis to explain what implementation processes took place and the interactions and gaps between the PD COMM interventions, the changing context, speech and language therapists and their practice. A within-trial economic evaluation in the form of cost–utility analysis was conducted from the perspective of the NHS. The primary results were expressed in terms of cost per quality-adjusted life-year (QALY) gained at 12 months for the three trial comparisons. Additional secondary analyses were performed from the NHS, personal social services perspective, broader societal perspective and using the capability approach, which uses broader measures of capability well-being. Results The mean age of participants in PD COMM was approximately 70 years old, and 74% were male (286/388). The mean duration of PD was between 5 and 6 years, with a broad range from newly diagnosed to over 30 years, and the majority (61%) were in Hoehn and Yahr stage of 2 or less (