Condition category
Nervous System Diseases
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
Parkinson’s disease (PD) is a common movement disorder, affecting approximately 120,000 people in the UK. It is a lifelong condition, which involves the gradual loss of nerve cells (neurons) in a part of the brain called the substantia nigra. These neurons are normally responsible for producing dopamine, a chemical messenger (neurotransmitter) which carries signals around the brain that help to coordinate movement. In people suffering from PD, these neurons gradually die over time, causing the level of dopamine in the brain to gradually fall. As the levels of dopamine become lower, the brain is unable to coordinate movement as effectively, causing abnormal movements such as stiffness, tremor (uncontrollable shaking) and slowness of movement (bradykinesia). Over two thirds of people with PD report having speech-related problems which has a great impact on their lives, leading to increased physical and mental demands during conversation, reduced independence and social withdrawal. Speech and language therapy (SLT) is recommended for people with PD but few patients are able to access it, with a recent Parkinson’s UK survey reporting that just 37% of the patients included had received SLT. This may be due to, in part, to the limited scientific evidence of a benefit of SLT for people with PD. Currently two different types of SLT are available in the UK: standard NHS SLT, which normally consists of one hour per week for six to eight weeks; and Lee Silverman Voice Training (LSVT), a more intensive therapy comprising of four sessions per week for four weeks. It is currently unclear if one or both of these treatments are effective or acceptable to people with PD, and if so, whether the benefits continue once the treatments have stopped. The aim of this study is to compare LSVT, traditional NHS SLT and a no therapy in people with PD.

Who can participate?
Adults with PD of unknown cause (idiopathic) who report problems with their speech/voice

What does the study involve?
Participants are randomly allocated to one of three groups. Participants in the first group receive four sessions of LSVT for four weeks. Participants in the second group receive traditional NHS SLT. The frequency of sessions varies but there is typically be one session per week for six to eight weeks. Participants in the third group do not receive any SLT for the duration of the study. Participants in all groups complete a number of questionnaires at the start of the study, and then again by post after 3, 6 and 12 months.

What are the possible benefits and risks of participating?
Participants who receive therapy may find it helpful in improving their speech/voice related problems. There may be a small increased risk of vocal strain or abuse, however this is minimal.

Where is the study run from?
The study is run from the University of Birmingham and takes place in 40 elderly care and neurology units in the UK.

When is the study starting and how long is it expected to run for?
October 2015 to September 2019

Who is funding the study?
National Institute for Health Research (UK)

Who is the main contact?
Mr Francis Dowling

Trial website

Contact information



Primary contact

Mr Francis Dowling


Contact details

Neuroscience Trials Office
Birmingham Clinical Trials Unit
Public Health Building
School of Health & Population Sciences
University of Birmingham
B15 2TT
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

A multi-centre randomised controlled trial to compare the clinical and cost effectiveness of Lee Silverman Voice Treatment versus standard NHS speech and language therapy versus control in Parkinson’s disease (PD COMM)



Study hypothesis

The aim of the study is to evaluate the effectiveness and cost-effectiveness of two types of speech and language therapy (SLT) compared to no treatment (control) for people with Parkinson’s disease (PD) who have self-reported problems with their speech or voice.

Ethics approval

West Midlands - Coventry & Warwickshire Research Ethics Committee, 17/12/2015, ref: 15/WM/0443

Study design

Phase 3 multicentre three-arm unblinded randomised controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details to request a patient information sheet


Specialty: Dementias and neurodegeneration, Primary sub-specialty: Parkinson's disease; UKCRC code/ Disease: Neurological/ Other disorders of the nervous system


Patient will be randomised to one of three study arms.

Group 1: Participants take part in four one-hour sessions of LSVT with a therapist per week and daily home based practice of varying length for four weeks. The focus of LSVT is to “think loud”; improving phonation and vocal loudness through better vocal fold adduction. The intervention will replicate the dose and content recommended by the originators and delivered in clinical practice and previous “standard” LSVT trials. The LSVT intervention consists of four 50 minute sessions per week delivered over four weeks. Each session follows a similar structure: 25 minutes of repeated and intensive maximum effort drills, and 25 minutes of high effort speech production task. Participants will also be set 5 to 10 minutes of home-based practice tasks on treatment days, and up to 30 minutes of home-based practice tasks on non-treatment days. The content of the intervention will consist of repeated repetitions of sustained “ah” phonation, maximum fundamental frequency range high and low pitch glides, and functional sentence repetition for the first half of each session, and exercises using speech hierarchy that progresses throughout the duration of the treatment programme (single word, phrases, sentences, paragraph reading, conversation) during the second half of the sessions. Throughout all of the sessions, the focus of the intervention will be to “think loud”, maintaining the vocal loudness produced during vowel phonation throughout all other task during the treatment.

Group 2: Participants will be prescribed NHS SLT as per usual local practice, this is likely to entail a one hour session per week over a 6 to 8 week period. Treatment will be individualised to suit each participant’s needs and local practice. The standard SLT may include interventions aimed at rehabilitating the underlying impairments of dysarthria, behavioural compensatory strategies and augmentative and alternative communication (ACC) strategies aimed at improving communicative function and participation. The participant’s family/ carer(s) will be involved as appropriate.
Treatments targeted at impairment level may include exercises focused on improving capacity, control and co-ordination of respiration, techniques for improving phonation intensity and co-ordination with respiration (but not LSVT), and exercises to improve the range, strength and speed of the articulatory muscles.
Behavioural therapy may include interventions aimed at reducing prosodic abnormality such as exercises targeting pitch, intonation, stress patterns, and volume variation, and techniques to address the overall rate of speech including the use of therapeutic devices such as pacing boards.
AAC strategies such as topic and alphabet supplementation through communication books and boards may be employed, along with AAC devices such as voice amplifiers, delayed auditory feedback systems, and masking devices. The practice of pitch limiting voice treatment may also be utilised within the standard SLT intervention. The above methods may include techniques used in LSVT e.g. vocal intensity exercises, but will be distinct by the individualised treatment, other SLT strategies, intensity of delivery and dose.
Dose will be determined by the participant’s individual needs, but the duration is unlikely to exceed twelve weeks of treatment. It is most likely to reflect the median dose as reported in a survey of current UK SLT practice for PD of 6 sessions delivered over 42 days. The PD COMM Pilot study found the median dose to be 6 sessions (range 1 – 12) over an average of 9.6 weeks (standard deviation 6.1 weeks).

Group 3: Participants allocated to no therapy, your general practitioner or hospital specialist to defer arranging any SLT until 12 months after you join the trial. Participant questionnaires will be completed at Baseline, 3, 6 and 12 month time points.

All participants will be expected to stay in the study for its 12 month duration. Participant questionnaires will be completed at Baseline, 3, 6 and 12 month time points. Participants randomised to therapy will expect to have received all therapy sessions by three months.

Carers of the main recruit can also join the study, if they have agreed to join, we would expect a short quality of life questionnaire to be completed at baseline, 3, 6 and 12 month time points.

Intervention type



Drug names

Primary outcome measure

The functional, physical and emotional impacts of a voice disorder on a patient's quality of life is measured using the Voice Handicap Index (VHI) at baseline 3, 6 and 12 months

Secondary outcome measures

1. Self-completion PRO designed to address aspects of functioning and well-being for those affected by Parkinson's disease is measured using the Parkinsons Disease Questionnaire 39 (PDQ-39) at baseline 3, 6 and 12 months
2. The impact that the voice disorder is having on the patient's voice-related quality of life is measured using the Voice related Quality of Life Scale (V-RQoL) is measured at baseline 3, 6 and 12 months
3. Evaluate the speech difficulties as perceived by individuals with dysarthria is measured using the Living with Dysarthria questionnaire (LwD) is measured at baseline 3, 6 and 12 months
4. Quality of Life measure is measured using the EQ-5D - Euroqol is measured at baseline 3, 6 and 12 months
5. Measure of capability in older people for use in economic evaluation is measured using the ICECAP-O (ICEpop CAPability measure for Older people) at baseline 3, 6 and 12 months
6. Resource Usage is measured using the resource usage questionnaire at baseline 3, 6 and 12 months
7. Carers Quality of Life is measured using the Parkinson's Disease Carers' Questionnaire at baseline 3, 6 and 12 months

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. People who have idiopathic PD defined by the UK PDS Brain Bank Criteria. These criteria are in standard use throughout the NHS in the UK and supported by the NICE guidelines
2. Person with PD or carer report problems with their speech or voice when asked
3. Aged 18 years and over

Participant type


Age group




Target number of participants

Planned Sample Size: 546; UK Sample Size: 546

Participant exclusion criteria

1. Dementia as usually defined clinically by the person with PD’s physician
2. Evidence of laryngeal pathology including vocal nodules or a history of vocal strain or previous laryngeal surgery within their medical records or from discussions with client, as LSVT is not appropriate for this group
3. Received SLT for PD speech or voice related problems in the past 2 years
4. The investigator is certain that the person with PD will not require SLT during the 12 months of the trial. Individual involvement in the trial is 12 months, but participants randomised to the deferred treatment group can be referred for therapy after 12 months

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

University of Birmingham
Neuroscience Trials Office Birmingham Clinical Trials Unit Public Health Building School of Health & Population Sciences
B15 2TT
United Kingdom

Sponsor information


University of Birmingham

Sponsor details

B15 2TT
United Kingdom

Sponsor type

Hospital/treatment centre



Funder type


Funder name

National Institute for Health Research

Alternative name(s)


Funding Body Type

government organisation

Funding Body Subtype

Federal/National Government


United Kingdom

Results and Publications

Publication and dissemination plan

1. Planned publication of a study protocol within the next 12 months
2. Planned publication of results paper and a HTA monologue at the end of the project

Intention to publish date


Participant level data

Available on request

Basic results (scientific)

Publication list

2017 protocol in:

Publication citations

Additional files

Editorial Notes

31/08/2017: Publication reference added.