Comparison of cognitive behaviour therapy versus activity management, both delivered remotely, to treat paediatric chronic fatigue syndrome/myalgic encephalomyelitis: the UK FITNET-NHS RCT.

Design: Parallel-group randomised controlled trial.

Methods: Adolescents aged 11-17 years, diagnosed with myalgic encephalomyelitis/chronic fatigue syndrome and with no local specialist treatment centre, were referred to a specialist service in South West England.

Interventions: Fatigue In Teenagers on the interNET in the National Health Service is a web-based myalgic encephalomyelitis/chronic fatigue syndrome-focused cognitive-behavioural therapy programme for adolescents, supported by individualised written, asynchronous electronic consultations with a clinical psychologist/cognitive-behavioural therapy practitioner. The comparator was videocall-delivered activity management with a myalgic encephalomyelitis/chronic fatigue syndrome clinician. Both treatments were intended to last 6 months.

Objectives: Estimate the effectiveness of Fatigue In Teenagers on the interNET in the National Health Service compared to Activity Management for paediatric myalgic encephalomyelitis/chronic fatigue syndrome. Estimate the effectiveness of Fatigue In Teenagers on the interNET in the National Health Service compared to Activity Management for those with mild/moderate comorbid mood disorders. From a National Health Service perspective, estimate the cost-effectiveness of Fatigue In Teenagers on the interNET in the National Health Service compared to Activity Management over a 12-month horizon.

Primary outcome: 36-item Short Form Health Survey Physical Function subscale at 6 months post randomisation.

Randomisation: Web-based, using minimisation with a random component to balance allocated groups by age and gender.

Blinding: While the investigators were blinded to group assignment, this was not possible for participants, parents/carers and therapists.

Results: The treatment of 314 adolescents was randomly allocated, 155 to Fatigue In Teenagers on the interNET in the National Health Service. Mean age was 14 years old and 63% were female.

Primary outcome: At 6 months, participants allocated to Fatigue In Teenagers on the interNET in the National Health Service were more likely to have improved physical function (mean 60.5, standard deviation 29.5, n = 127) compared to Activity Management (mean 50.3, standard deviation 26.5, n = 138). The mean difference was 8.2 (95% confidence interval 2.7 to 13.6, p = 0.003). The result was similar for participants meeting the National Institute for Health and Care Excellence 2021 diagnostic criteria.

Secondary outcomes: Fatigue In Teenagers on the interNET in the National Health Service participants attended, on average, half a day more school per week at 6 months than those allocated Activity Management, and this difference was maintained at 12 months. There was no strong evidence that comorbid mood disorder impacted upon the relative effectiveness of the two interventions. Similar improvement was seen in the two groups for pain and the Clinical Global Impression scale, with a mixed picture for fatigue. Both groups continued to improve, and no clear difference in physical function remained at 12 months [difference in means 4.4 (95% confidence interval -1.7 to 10.5)]. One or more of the pre-defined measures of a worsening condition in participants during treatment, combining therapist and patient reports, were met by 39 (25%) participants in the Fatigue In Teenagers on the interNET in the National Health Service group and 42 (26%) participants in the Activity Management group. A small gain was observed for the Fatigue In Teenagers on the interNET in the National Health Service group compared to Activity Management in quality-adjusted life-years (0.002, 95% confidence interval -0.041 to 0.045). From an National Health Service perspective, the costs were £1047.51 greater in the Fatigue In Teenagers on the interNET in the National Health Service group (95% confidence interval £624.61 to £1470.41). At a base cost-effectiveness threshold of £20,000 per quality-adjusted life-year, the incremental cost-effectiveness ratio was £457,721 with incremental net benefit of -£1001 (95% confidence interval -£2041 to £38).

Conclusion: At 6 months post randomisation, compared with Activity Management, Fatigue In Teenagers on the interNET in the National Health Service improved physical function and school attendance. The additional cost of Fatigue In Teenagers on the interNET in the National Health Service and limited sustained impact mean it is unlikely to be cost-effective.

Trial registration: This trial is registered as ISRCTN18020851.

Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 14/192/109) and is published in full in Health Technology Assessment; Vol. 28, No. 70. See the NIHR Funding and Awards website for further award information.