Acceptance and commitment therapy for people living with motor neuron disease: the COMMEND feasibility study and randomised controlled trial

Background

Motor neuron disease is a progressive, fatal neurodegenerative disease for which there is no cure. Formal psychological therapies are not routinely part of United Kingdom standard motor neuron disease care due to a lack of evidence-based guidance resulting from a paucity of clinical trials. We aimed to evaluate the clinical and cost-effectiveness of Acceptance and Commitment Therapy plus usual care compared to usual care alone for improving psychological health in people living with motor neuron disease.

Methods

We conducted qualitative interviews with 15 people living with motor neuron disease, 10 caregivers and 12 healthcare professionals. Findings were used to develop an Acceptance and Commitment Therapy intervention specifically for people living with motor neuron disease. Next, we examined its acceptability and feasibility in an uncontrolled feasibility study with 29 people living with motor neuron disease. Findings from qualitative interviews with 14 people living with motor neuron disease and 11 therapists were used to revise the intervention. Finally, we conducted a multicentre, parallel, two-arm randomised controlled trial in 16 United Kingdom motor neuron disease care centres/clinics. Eligible participants were aged ≥ 18 years with motor neuron disease. Participants were randomly assigned (1 : 1) to receive up to eight sessions of Acceptance and Commitment Therapy plus usual care or usual care alone and followed up at 6 and 9 months post randomisation by blinded outcome assessors. The primary outcome was total score on the McGill Quality of Life Questionnaire-Revised at 6 months. Secondary outcomes included health status using the EuroQol-5 Dimensions, five-level version. Primary analyses were by intention to treat.

Results

Acceptance and Commitment Therapy was acceptable to people living with motor neuron disease, and it was feasible to recruit participants, hence trial progression criteria were met. From September 2019 to August 2022, 191 participants were recruited: 97 were allocated to Acceptance and Commitment Therapy plus usual care and 94 to usual care alone. Mean age was 61.9 years (standard deviation 11.4), 58% were male and 95% were White/White British. Acceptance and Commitment Therapy plus usual care was superior to usual care alone on the McGill Quality of Life Questionnaire-Revised at 6 months [adjusted mean difference 0.66 (95% confidence interval 0.22 to 1.10); Cohen’s d = 0.46 (95% confidence interval 0.16 to 0.77); p = 0.003] and 9 months [adjusted mean difference 0.76 (95% confidence interval 0.30 to 1.22); Cohen’s d = 0.53 (95% confidence interval 0.21 to 0.85); p = 0.001]. Mean differences in total costs and quality-adjusted life-years at 9 months between Acceptance and Commitment Therapy plus usual care versus usual care alone were not statistically significant [costs: £1019 (95% confidence interval −£34 to £2074); quality-adjusted life-years: 0.019 (95% confidence interval −0.07 to 0.05)]. The incremental cost-effectiveness ratio was £88,507/quality-adjusted life-year: this decreased to £13,817/quality-adjusted life-year in those with medium disease-related deterioration in subgroup analyses.

Conclusion

Acceptance and Commitment Therapy plus usual care is clinically effective at maintaining or improving psychological health, as measured by the McGill Quality of Life Questionnaire-Revised, in people living with motor neuron disease compared to usual care alone. It was not cost-effective overall when calculated using a standard health status measure (EuroQol-5 Dimensions, five-level version). However, it was cost-effective in a subgroup of people experiencing a medium rate of disease-related deterioration.

Limitations

Participants from ethnic minorities were under-represented, despite recruiting from sites with diverse communities. Between-group differences in outcomes may have been partly attributable to expectancy or non-specific therapeutic effects due to the lack of an active control. Cost-effectiveness analyses may have been underpowered to detect significant between-group differences.

Future work

Studies should examine the effectiveness of Acceptance and Commitment Therapy in diverse populations, compared to an active control, using a more appropriate measure to assess cost-effectiveness, and in those with different rates of disease-related deterioration.

Funding

This synopsis presents independent research funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme as award number 16/81/01.