Table 1 VERSE reporting for TIDieR and Behaviour Change Consortium treatment fidelity recommendations

Study design

Ensure same treatment dose within conditions

• The intervention time for the VERSE trial was a maximum of 25 working days after baseline assessment; allowing up to 14 days to recruit and assess, the intervention period for all participants ceased at day-50 post stroke if not completed earlier.

• The two intensive arms were designed to deliver the same dose within each condition (20 sessions of 45–60 min or 15–20 h of direct aphasia therapy). Each group was monitored to confirm therapy amount was within the prescribed range.

Ensure equivalent dose across conditions

• All video-recorded sessions were cross-checked with data entered into REDCap® [19] to ratify correct number and length of sessions, treatment type (direct aphasia therapy as compared to assessment, counselling or education) and allocated treatment group (e.g. VERSE treatment as compared to Usual Care therapy).

• Usual care therapy dose was expected to vary within the condition as per the control design.

Plan for implementation setbacks

• An additional five working days (to maximum day-50) was allowed for the intensive intervention to be completed due to known treatment barriers in early stroke recovery.

• A pool of ‘intensive therapists’ trained exclusively in each intensive regimen, i.e. UC-Plus and VERSE arms, was available so that implementation did not rely on one therapist.

• Provider attrition was tracked through a VERSE substudy.

Training providers

Standardise training

• All assessors and therapists in intensive regimens were qualified speech pathologists.

• All therapists and assessors received 1–3 h of face-to-face or videoconference training.

• Usual Care, UC-Plus therapists, Principal Investigators, baseline and blinded assessors received (relevant to their role):

o Written study protocol

o Training power point slides

o Written therapy and data entry manuals

o Access to a ‘training mode’ REDCap® [19] database

o Introduction and access to trial monitoring staff for support throughout the trial

o Assessment kits (standardised assessments, video recorder, recording forms)

• VERSE therapists received the above materials and:

o Specific additional VERSE training emphasising the prescribed treatment regimen

o VERSE-specific training manual

o VERSE treatment plans for each goal of the treatment hierarchy

o Pre-reading material outlining treatment theory

o VERSE treatment task hierarchy

o Therapy recording sheets

o Video-recorded examples of VERSE therapy

o Frequently asked questions document

o Standardised VERSE training kit/therapy materials

Ensure provider skill acquisition

• VERSE therapists were encouraged to ‘practise’ the treatment regimen before commencing trial treatment.

• VERSE and UC-Plus therapists were required to video-record one therapy session per week (approx. four recordings per participant). For practical reasons therapists were encouraged to record every 5th session however, therapy videos for any session were accepted. Video recording for therapists providing usual care sessions was as per standard care.

• Baseline and blinded assessors’ audio recorded connected speech samples as part of the assessments. Feedback from the treatment fidelity monitor was provided if the assessor required support in elicitation of either monologic or dialogic samples.

Minimise therapist drift

• Monitoring of therapy videos per above.

• Ongoing updates and reminders about the trial were included in monthly VERSE newsletter which included generic treatment tips.

• UC and UC-Plus therapists were encouraged to contact the treatment fidelity monitor with treatment queries.

• VERSE therapists contacted the treatment fidelity co-ordinator with treatment queries.

• Videos were examined as soon as received. General session feedback (e.g. length, frequency of session) for VERSE therapists was provided by the treatment fidelity monitor. Treatment-specific feedback was provided by the treatment fidelity coordinator if 20% of the targeted therapeutic interactions / behaviour was deemed non-adherent (Fig. 1).

Accommodate provider differences

• The VERSE Expert Advisory Committee determined that 80% was a clinically acceptable level of protocol adherence whilst accommodating for provider differences within sessions. A session was considered compliant if 80% of the total interactions and activities within the session were adherent.

Delivery of treatment

Control for provider differences

• All video-recorded sessions were reviewed and rated against key criteria (Supplement 1). Non-compliant sessions were defined as sessions containing more than 20% of non-compliant interactions. If UC-Plus sessions did not comply with treatment frequency and session length, the treatment fidelity monitor raised the issue with the treating therapist. If VERSE treatment sessions were deemed non-compliant by the treatment fidelity monitor, they were escalated to the treatment fidelity coordinator who addressed the non-compliant behaviour with the therapist.

• Regular communication to VERSE therapists to remind them of key therapy features

Reduce differences within treatment

• Written therapy manual and video-recorded examples of treatment at different difficulty levels were provided to therapists.

• Feedback provided to therapists if main and intervention protocol adherence needed to be addressed.

• Ongoing updates and reminders about the trial were included in a monthly VERSE newsletter.

Ensure adherence to protocol

• Videoed therapy sessions were monitored for protocol adherence per above.

• Example VERSE therapy plans with scripted task explanations were given to therapists

• Therapy deviations were reported and recorded in REDCap® [19].

• Ongoing regular access to trial staff for questions and direction as required.

Minimise contamination between conditions

• Treatment materials were specific to the intervention arm of the trial, marked confidential and only provided to therapists within that arm.

• VERSE therapists were trained specifically to minimise intervention contamination and were instructed not to disclose VERSE therapy to non-VERSE therapists or assessors.

• Once trained, VERSE therapists could not undertake a UC or UC-Plus role.

• Sessions were conducted in a quiet and private place so as not be in ear-shot of others.

• Videoed sessions were reviewed to identify any contamination between the arms of the trial.

Receipt of treatment

Ensure participant comprehension

• Aphasia-friendly informed consent was obtained.

• Participants with very low comprehension recruited to the trial were supported in the intervention as required by trained Speech Pathologists.

• VERSE arm participants were treated with an intervention plan that stipulated a demonstrated comprehension of at least 50 single words (Goal 1 was a comprehension only goal) before progressing to Goal 2. See supplementary materials supplement for treatment goals.

Ensure participant ability to use cognitive skills

• The intervention was structured around achievement-based objectives

• VERSE therapy included the introduction of incremental levels of communication complexity involving comprehension and verbal expression. If 80% accuracy on the current goal was achieved, it was determined that the participant had sufficient comprehension and cognitive skills to progress to the next therapy goal

Ensure participants ability to perform behavioural skills

• Success at each level within the VERSE treatment programme meant the participant had sufficient comprehension and cognitive skills to perform the desired behaviours. All 20 VERSE therapy sessions and goals were recorded, providing a clear outline of the development of targeted behaviours

Enactment of treatment skills

Ensure participant use of cognitive skills

• Enactment of these skills beyond the therapy session was not monitored and not a focus of this research.

Ensure participant use of behavioural skills

• Per above.