Aims and objectives
The study objectives were to (i) evaluate feasibility and acceptability of GREAT- strides; and (ii) the feasibility of a future trial. More specifically, aims were:
-
To evaluate patient and therapists’ perceptions of acceptability of the gait rehabilitation intervention.
-
To evaluate the initial safety of, and adherence to the gait rehabilitation intervention.
-
To evaluate the fidelity of intervention therapist training and delivery of the gait rehabilitation intervention.
-
To evaluate selected measurement properties and characteristics of candidate outcome measures to select the most suitable primary outcome measure for a future main trial.
-
To monitor rates of recruitment, attrition and data completeness.
Design
This study was a multi-centre (n=4), a single-arm, repeated measures (pre- and post-intervention) design with nested qualitative studies. This feasibility study was reviewed and approved by the West of Scotland Research Ethics Committee 3 (17/WS/0264) in January 2017.
Settings
The study was conducted in outpatient rheumatology (recruitment) and rehabilitation (physiotherapy and podiatry) settings in 4 United Kingdom National Health Service (NHS) Hospitals in Glasgow (Gartnavel General Hospital and Glasgow Royal Infirmary, NHS Greater Glasgow and Clyde), Stoke-on-Trent (Haywood Hospital, Midlands Partnership Foundation Trust), and London (King’s College Hospital NHS Foundations Trust).
Participants
Participants were included if they: (a) were aged ≥18 years, (b) diagnosed with RA (American College of Rheumatology (ACR) 2010 classification criteria [41]) within the previous 2 years, (c) had disease-related foot impairments defined as: (i) self-reported foot pain, and/or (ii) the presence of foot/ankle joint synovitis/tenosynovitis detected during routine rheumatology clinical examination. Exclusion criteria included contraindications to the intervention identified by their consulting rheumatologist, those who were unable or unwilling to provide informed consent; or were taking part in other non-medical intervention studies affecting lower limb function.
Recruitment
Potential participants were identified by rheumatology team members in one of two ways. Rheumatology clinic lists were screened by the direct care team and potentially eligible patients who were interested in the study were introduced to the research team. A second approach involved initial screening of clinic lists by trial personnel at participating sites. Written invitation letters were sent to potentially eligible patients. Patients interested in the study responded using an expression of interest form, and were contacted by the recruiting researcher to confirm eligibility and willingness to participate. Once eligibility was confirmed, all eligible patients were invited to attend an initial appointment where written informed consent was obtained and baseline assessment completed.
Intervention development
Informed by MRC guidelines for the development of complex interventions [39], GREAT Strides was developed by people with RA, rheumatology specialist physiotherapists, podiatrists, health psychologists and clinical academics experienced in intervention development. It drew on existing exercise programmes for older adults and people with RA [37, 38, 42–45], and incorporated psychological components to address adherence [46–49]. a series of Patient and Public Involvement (PPI) and stakeholder engagement workshops/interviews were conducted. At the final workshop, the specific intervention components and therapist training plans were agreed by consensus.
The GREAT Strides intervention
GREAT Strides is a theoretically underpinned psychologically informed home-based 12-week gait rehabilitation programme which included two compulsory face-to-face sessions and up to four additional sessions with trained therapists over a 12-week period. GREAT Strides was comprised of
-
A circuit of six repetitive walking tasks designed for setup and completion at home (Figure 1).
-
The psychological components of GREAT Strides are based upon motivational interviewing (MI) to support participants to overcome barriers and facilitate translation of intentions into action [46, 47]. MI is a collaborative, goal-oriented style of communication where particular attention is paid to the language of change [47]. GREAT Strides is underpinned by the Theory of Planned Behaviour (TBP) [48, 49]. This model places emphasis on individuals’ perceived ability to perform a given behaviour and their attitudes to initiating behavioural change [50]. Specific behaviour change techniques (BCTs) have been incorporated into the intervention to facilitate adherence (Table 1).
-
Participants were provided with an educational booklet, an exercise diary, and a digital versatile disc (DVD) including step-by-step demonstrations of gait circuit home set-up and task completion. All resources were also available on a dedicated study website [53].
Session 1 involves six core components: an overview of the intervention, brief clinical assessment of disease activity and functional status, conducing a psychological assessment using the principles of motivational interviewing. demonstration of the circuit, dose setting, and the delivery of 17 BCTs (Table 1), and provision of support materials. Session 2 (1-4 weeks after session 1) involved delivery of 4 core components and 12 BCTs (Table 1), further dose and circuit adaptation as required. Sessions 3-6 were optional (same core components and BCTs as session 2) and could be face-to-face or telephone-based according to participants’ needs to maintain contact, promote adherence and/or to provide specific advice regarding progression.
The setting of the starting dose is undertaken by instructing participants to complete one full set of the circuit (1 minute per task) followed by immediate rating of perceived exertion using a modified version of the Borg Rating of Perceived Exertion (RPE) scale (range 6-20). The starting dose equals the number of sets required to achieve an RPE from 13 up to 17 (equivalent to 50-80% maximal exertion) [51, 52] and frequency set initially at 3 times per week.
Table 1
The core components and BCTs for GREAT Strides intervention sessions.
Session 1
|
Sessions 2-4
|
Core components
|
BCTs
|
Core components
|
BCTs
|
Gives a short overview of the GREAT intervention.
Conducts a brief clinical assessment.
Conducts a psychological assessment using the principles of motivational interviewing.
Completes the worksheets from the patient support booklet.
Gives patient a DVD and manual.
Confirms appointment for session 2.
|
Provides information about health consequences.
Verbal persuasion about capability.
Discuss discrepancy between current behaviour and goals.
Discuss pros and cons.
Demonstration of the behaviour.
Instructions on how to perform the behaviour.
Behaviour practice/rehearsal.
Feedback on behaviour.
Goal setting (behaviour).
Goal setting (outcome).
Problem solving.
Action planning.
Graded tasks.
Prompts and cues.
Self-monitoring of behaviour.
Social support.
Commitment.
|
Review progress on gait circuit.
Checks gait circuit progression.
Completes and/or reviews the worksheets from the patient support booklet.
Signposts to local walking groups.
|
Verbal persuasion about capability.
Review behavioural goal.
Feedback on behaviour.
Problem solving.
Goal setting (outcome).
Social support (unspecified).
Demonstration of the behaviour.
Instructions on how to perform the behaviour.
Behaviour practice/rehearsal.
Goal setting (behaviour).
Graded tasks.
Action planning.
|
Therapist intervention training
Eleven therapists across the three sites received a bespoke training package (8 hours training over two days delivered face to face two weeks apart) to deliver GREAT Strides. Training was delivered by the GREAT trial team (GJH, AP, LB, EG, MS). It included set up and delivery of the gait circuit, dose setting, and how to apply MI and BCTs to help patients complete their walking exercises regularly. Therapists were also provided with a clinician manual to accompany the training content and access to electronic resources on the study website [53].
Feasibility outcomes
Intervention acceptability, safety and adherence
Participant acceptability was evaluated using a 3-item questionnaire which utilises 5-point Likert scales for responses, adapted from previous trials [54, 55]. Study and intervention safety were monitored by examining rates of serious adverse events (SAEs) and expected events of interest (see Additional File 1) deemed to be related to the intervention. Treatment adherence was evaluated using the Exercise Adherence Rating Scale (EARS), a valid and reliable self-reported measure of adherence to prescribed exercise therapies [56].
Qualitative explorations of intervention acceptability, adherence and safety
Patient interviews
A purposive sub-sample of participants were identified at the end of the 12-week intervention period for telephone interviews by an independent researcher (AW). The interview was conversational in style and allowed the participant to speak freely about their experience and opinions. Several trigger questions were used to keep the conversation focussed (Additional File 2). The interview was recorded using a digital recorder and data transcribed verbatim by a commercial company (Outsec Services Limited, Swaffham, UK). Thematic analysis was undertaken initially using a thematic network approach [57]. Thematic analyses were independently verified by an additional qualitative researcher. At the third iteration of interpretation, relevant themes were aligned to the Theoretical Framework of Acceptability (TFA) for healthcare interventions [58].
Therapist interviews
All therapists were invited to attend a telephone semi-structured interview to explore the acceptability of training and delivery of GREAT Strides. A topic guide informed by the TFA was developed a priori [58] (Additional File 3). One researcher (MS) conducted all interviews, and data were transcribed verbatim by a commercial company (The Typing Works, Middlesex, UK). A deductive thematic analysis was applied in which the TFA was applied as the coding framework. Data were coded into six TFA constructs (affective attitude; burden; intervention coherence; opportunity costs; perceived effectiveness; self-efficacy). Inductive themes within each of the TFA constructs were reviewed amongst the primary coder (MS) and two additional qualitative researchers (LB, EG), until consensus was reached.
Fidelity of motivational interviewing delivery
All GREAT Strides sessions were audio recorded. Randomly selected 20-minute segments of audio recordings were rated for proficiency of MI delivery by two trained, independent raters using the Motivational Interviewing Treatment Integrity Scale 4.2.1 (MITI, 4.2.1) [59]. Motivational Interviewing technical proficiency (application of MI techniques [range 1-5] 3=fair proficiency) and relational proficiency (interpersonal style [range 1-5] 3.5=fair proficiency) were assessed.
Behaviour Change Techniques delivery
Bespoke checklists were developed to assess fidelity of delivery of 6 core intervention components delivered in sessions 1, 4 core components delivered in sessions 2-6, 17 BCTs delivered in session 1, and 12 BCTs delivered in sessions 2-6. Two independent assessors trained in applying the Behaviour Change Technique Taxonomy V1 [60] rated the full audio recordings of GREAT sessions. High treatment fidelity was calculated according to whether a minimum of 80% of core components and BCTs within each session were rated as being fully delivered by clinicians.
Candidate primary outcome measures for the future trial
Four measures of lower limb/foot disability with good measurement properties in people with RA [61–65] were selected for evaluation as potentially suitable primary outcome measures for the future randomised controlled trial. The Foot Function Index (FFI) disability subscale is a patient-reported outcome measure designed to measure self-reported foot-related disability. Responses are made using 100mm visual analogue scales and a summary score obtained by calculating the mean of the nine items, with higher scores indicative of greater foot-related disability [61]. The Patient Reported Outcome Measurement Information System Physical Function Short Form (PROMIS PF-20) is an outcome measure of physical function [62]. Responses are made using twenty 5-level Likert scales, and summary score calculated by summating and converting to a T-score ranging from 9.2-62.7, with lower scores indicative of greater functional impairment. The Recent-Onset Arthritis Disability (ROADles) lower extremity subscale is a measure of lower extremity physical function [63]. Responses are made using four 5-point Likert scales and scores summated and normalised (scores x 0.625) to a summary score ranging from 0-10 (higher scores representing poorer status). The 10-metre walk test (10MWT) is an objective measure of walking capacity/functional mobility. It is the time taken to walk 10 metres with greater time indicative of poorer functional status. Participants’ perceptions of the overall treatment effect were recorded at 12-week follow-up using a 7-point global rating of change scale (defined as change in walking ability [CWA]) as a patient-rated anchor [66] from “Very much worse” to “Very much better”.
Recruitment rates, attrition, and data completeness
Future trial feasibility was further explored through examination of recruitment rates, rates of attrition, and rates of completion of outcome measures.
Study schedule and procedures
Study schedule and procedures details are provided in Table 2.
Table 2
Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) table for study procedures.
|
Pre study screening/ consent
-1
|
Baseline
0
|
Compulsory clinical visit 1
T1
|
Compulsory clinical visit 2
T2
|
Optional clinical visits 3-6
T3-6
|
12 weeks follow up
F1
|
Enrolment
|
|
|
|
|
|
|
Eligibility screen
|
x
|
|
|
|
|
|
Informed consent
|
x
|
|
|
|
|
|
Measurements
|
|
|
|
|
|
|
Patient acceptability questionnaire
|
|
|
|
|
|
x
|
EARS
|
|
|
|
|
|
x
|
FFI-DS
|
|
x
|
|
|
|
x
|
PROMIS PF-20
|
|
x
|
|
|
|
x
|
ROADles
|
|
x
|
|
|
|
x
|
10MWT
|
|
x
|
|
|
|
x
|
CWA 7 point scale
|
|
|
|
|
|
x
|
Qualitative telephone interviews
|
|
|
|
|
|
x
|
Intervention
|
|
|
|
|
|
|
GREAT Strides
|
|
|
x
|
x
|
x
|
|
Statistical analyses
Recruitment/retention, demographic and clinical data
Recruitment, retention and data completeness rates were calculated using absolute (number of participants [n]) and relative (percentages [%]) frequencies. Monthly recruitment rate was estimated using the mean and associated 95% confidence interval (95% CI). Demographic and clinical data are expressed as median (inter-quartile range [IQR]) for data that were not normally distributed, and absolute (n) and relative (%) frequencies for nominal data. Intervention acceptability questionnaire item responses and adverse events (AEs) were analysed using absolute (n) and relative (%) frequencies. Intervention adherence was analysed using the median (IQR) summary score for the EARS questionnaire.
Primary outcome data
In order to select the most appropriate instrument for subsequent project phases, an evaluation of measurement properties including minimal important difference (MID), longitudinal validity and responsiveness to change over 12 weeks was planned, subject to availability and completeness of study data. The MID was estimated by calculating the mean change score in participants who improved according to the CWA (anchor), minus the mean change score in participants who did not improve or whose symptoms worsened, with associated 95% CIs. Linear associations of change scores were determined between candidate outcome measures and the CWA using Pearson’s correlation coefficient and 95% CIs. Responsiveness was to be evaluated using four different effect size statistics: the paired t-test, Cohen’s d, standardised response mean (SRM) and the Guyatt index (GI) [67–70].
Sample size
An a priori sample size calculation was undertaken based on the evaluation of measurement properties of primary outcome candidates. A sample size of at least n=42 would allow detection of a magnitude of association (correlation coefficient) of at least 0.65 between the selected anchor (CWA) and outcome measures at 5% significance with 80% power, accounting for 20% attrition.