Nielsen 2017.

Study characteristics
Methods	Study design: randomised controlled trial Study grouping: parallel group Adequate power (evidence of power calculation): a power calculation was not performed as the primary aim of this study was to assess feasibility. Allocation concealment method: none. Both participants and clinicians were unmasked to treatment allocation. Blinding of outcome assessors: participants were immediately informed of their treatment allocation. Both participants and clinicians were unmasked to treatment allocation. Check of blinding: none. Both participants and clinicians were unmasked to treatment allocation. Duration of study: 8 September 2014 to 4 June 2015 Randomisation method: randomly allocated (1:1) to the intervention or control group using a secure online randomisation application (Sealed Envelope, London, UK)
Participants	Baseline characteristics Intervention n: 30 Duration of symptoms (mean): 5.9 (SD 8.3) years Age (mean): 44 (SD 13.1) years Sex (% woman): 73% Marital status currently married (%): 63% Educational status – degree level: 43% Control n: 30 Duration of symptoms (mean): 5.6 (SD 6.2) years Age (mean): 41 (SD 13.1) years Sex (% woman): 70% Marital status currently married (%): 60% Educational status – degree level: 30% Overall n: 60 Duration of symptoms (mean): 5.8 (SD 7.3) years Age (mean): 43 (SD 13.1) years Sex (% woman): 43 (72%) Marital status currently married, n (%): 37 (62%) Educational status – degree level: 37% Inclusion criteria: clinically established diagnosis of FMS according to Fahn‐Williams criteria; aged ≥ 18 years; completed diagnostic investigations; acceptance of the diagnosis on the balance of probability (i.e. quote: "we did not exclude patients who continued to express some doubt over the diagnosis"); FMS duration ≥ 6 months; symptoms severe enough to cause distress or impairment in social or occupational functioning. Exclusion criteria: unable to understand English; pain or fatigue that was the primary cause of the patient’s disability; prominent dissociative seizures for which the patient required assistance to manage; clinically evident anxiety or depression that required assessment before starting physiotherapy treatment; high level of disability that prevented participation in an outpatient/day hospital environment; unable to attend 5 consecutive days of treatment. Pretreatment: inspection of baseline data suggested that the control group had generally worse scores than the intervention group, which were accounted for in the analysis.
Interventions	Intervention characteristics Intervention Description: 5‐day specialised physiotherapy‐led intervention. The intervention was a protocolised 5‐day programme, delivered by a neurophysiotherapist who had undertaken additional specific training. Participants were admitted to a day hospital for 5 consecutive days, within 4 weeks of baseline assessment. The first session was a joint consultation with the neurologist and physiotherapist where diagnostic information was reviewed and the aims of the programme discussed. These were explained as retaining movement and learning how to manage symptoms in the longer term. The programme consisted of 8 sessions over 5 consecutive days, each lasting 45–90 minutes. Length of treatment: 5 days, but with intake a total of 4 weeks Longest follow‐up after end of treatment: 5 months Comedications/other treatments while in the study: each participant received a standard comprehensive explanation of the diagnosis. The participant was also referred to online sources of information (www.neurosymptoms.org; www.FNDHope.org). Control Description: TAU. A referral was made to the participant’s local neurophysiotherapy service. The referral letter contained information about the diagnosis, specific treatment goals and contact for further information regarding the diagnosis or treatment advice Length of treatment: 4 weeks Longest follow‐up after end of treatment: 5 months Comedications/other treatments while in the study: each participant received a standard comprehensive explanation of the diagnosis. The participant was also referred to online sources of information (www.neurosymptoms.org; www.FNDHope.org).
Outcomes	Physical symptom load (SF‐36 – Physical Component) Outcome type: continuous Mental state – anxiety (HADS) Outcome type: continuous Mental state – depression (HADS) Outcome type: continuous Level of functioning (WSAS) Outcome type: continuous Dropout Outcome type: dichotomous Data value: endpoint
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Eligible consenting participants were randomly allocated (1:1) to the intervention or control group using a secure online randomisation application (Sealed Envelope, London, UK)."
Allocation concealment (selection bias)	Unclear risk	No information provided.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote: "Participants were immediately informed of their treatment allocation. Both participants and clinicians were unmasked to treatment allocation."
Blinding of outcome assessment (detection bias) All outcomes	High risk	Quote: "Participants were immediately informed of their treatment allocation. Both participants and clinicians were unmasked to treatment allocation."
Incomplete outcome data (attrition bias) All outcomes	High risk	Data were missing from end of treatment on the parameter. The study authors considered the SF‐36 – Physical Component the best measurement.
Selective reporting (reporting bias)	Low risk	Matches study protocol.
Other bias	Low risk	Baseline group differences, but they were adjusted for.