Soles of the Feet Meditation Intervention for People with Intellectual Disability and Problems with Anger and Aggression—a Feasibility Study

The mean age of the 19 participants was 34.8 years (SD 8.93), consisting of 12 males (63.2%). The presence of an ID was assessed through administration of the Wechsler Abbreviated Scale of Intelligence–2nd Edition (WASI-II: Wechsler, 2011: M = 57.15, SD = 7.39) and the Adaptive Behavior Assessment System®–2nd Edition (ABAS: Harrison and Oakland 2003: M = 63.24, SD = 7.10). Carers who supported participants were either family members (N = 9), or paid support staff (N = 10). Participants were identified by NHS clinicians employed by a single UK health organization. Inclusion criteria were that participants were 18 years old or over, that the presence of an ID was confirmed, that there were clinically significant difficulties with anger control as assessed by their clinician, that the participant was able to give informed consent, and that a family member or paid carer could be available to be with the participant during intervention sessions, who had supported them for a minimum of 6 months, and who provided a minimum of 2-h support per week. Although language ability was not an inclusion criterion, the ability to give informed consent indicated that the participant would also have the language level needed to participate in the UK SoF intervention. Exclusion criteria were an existing diagnosis of Autism Spectrum Disorder (ASD) due to potential difficulties the participant with ID and the addition of an ASD diagnosis might have with more abstract concepts, that there was the presence of mental health problems or behavior that would prevent the participant from interacting with the therapist or carer or retaining information (e.g., dementia, active psychosis), and individuals who were in receipt of another direct psychological intervention at the time of the study (e.g., relaxation training, dialectical behavior therapy, cognitive behavior therapy).

An initial screening visit (by a trained researcher) sought informed consent. Data were collected during face-to-face sessions with the researcher at the participant’s home or a place of their choice (e.g., their local clinic). Following the initial screening visit, a baseline visit occurred prior to the commencement of the intervention. Within 2 weeks of baseline measure completion, the intervention began and was delivered to the participant by a trained therapist employed by the NHS. Follow-up visits took place at 2 and 6 months post-baseline.

This feasibility study was a single-arm study with three measurement time points: (1) baseline, (2) immediately after the intervention (2 months post-baseline), and (3) follow-up (6 months post-baseline). Qualitative data was also taken at follow-up and is reported in Griffith et al. (2019). Feasibility metrics (e.g., recruitment and retention rates, clinical characteristics, duration of the intervention) were analyzed, together with adherence outcome, participant acceptance, and adherence to the intervention. No hypotheses were tested, and no formal analysis of outcome variables was made as the study was not powered for definitive analysis. However, the mean change from baseline together with associated variances was calculated for all measures and presented as point estimates together with 95% confidence intervals. An estimation of the precision of the means and variances will inform the power calculation of any future RCT protocol. No imputation or pro-rating of missing data occurred over and above that stipulated by the scoring routines for the measures, due to the feasibility nature of the study.

Table 2 indicates the primary outcomes of the study relating to recruitment, retention, and adherence. Recruitment of participants from those identified as eligible was 90.5%. Of those screened, 80% were recruited. This indicates identification of appropriate screening pathways and a high level of participant sign-up to the study. There were three participants who were ineligible. The first of these had an IQ over 75, and diagnoses of autism and borderline personality disorder. The remaining two both had diagnoses of autism. Two potential participants were deemed eligible but did not take part. Both were matched with therapists; one person proved difficult to contact while the other upon contact doubted they would have time to commit and had changed their mind about participating.

Appendix B (supplemental materials) depicts the numbers of completed measures recorded at each time point. None of the scoring routines for the measures stipulated rules for handling missing items; therefore, if one item was missing, the measure was considered incomplete, and a score was not calculated. The measures were tolerated well with evidence that if a participant started a measure, they would complete it. The CHU-9D appeared to have the lowest completion rate with the ‘Work/College’ item causing the most problems.

Table 3 provides the raw score descriptive statistics for each of the outcome measures recorded at each of the time points. Paired samples t tests were completed for baseline to 2-month and 6-month follow-ups. Table 4 presents the mean differences achieved pre to post, associated 95% confidence interval, effect size, and an indication of the direction of the change. Mean changes were calculated as baseline score minus follow-up time point; therefore, an increase in the measure is denoted by a negative mean difference. For the majority of measures, a positive result would be to see a reduction in score (thus a positive mean difference in the table). For EQ-5D-Y, ICECAP-A, and CHU-9D an increase in the measure is positive, and therefore, a negative mean difference value would be preferable.

In Table 4, the mean difference between the time points has been interpreted in terms of being in favor or not of SoF. For the initial post intervention comparison, it was evident that the change was positive for the specific measures and not for the more generic measures. The directional effect was less clear at the longer follow-up time point which would be looking at maintenance of effect beyond those being provided by the initial treatment period.

All results are based on small samples and care needs to be taken in drawing conclusions. For example, the GDS proxy in particular, was completed by very few carers (six completed cases for initial comparison and reducing to three for the longer term follow-up). Simple effect sizes are also given in Table 4. These have been calculated as Cohen’s d and represent the effect size seen in pre-to-post measurement. These effect sizes are indicative of a pre-to-post change rather than a between-group effect size that may be seen in an experimental design study.

Of the 14 participants who fully completed the 6-week intervention, a total of 24 sessions from a potential 28 were recorded. Of these, a total of 13 randomly selected recordings were rated by two independent, trained raters for reliability analysis. Average absolute agreement was established using a two-way, mixed model ICC on summary scores for part two (delivery) of the fidelity checklist which was 0.71. According to Koo and Li (2016), this indicates moderate reliability (range .5–.75). This suggests that single rater scores on this section of the fidelity checklist are a reliable measure. Intervention fidelity ratings on a sample of 13 recordings on part one of the fidelity checklist showed that on average, 84.64% of the 11 items stipulated for each session were covered. Across the same sample of recordings, on average, 80.15% of the key components for each session were delivered indicating a high level of fidelity for both adherence and delivery.

As the primary aim of the current study focused on the feasibility of delivering the UK SoF intervention it was also prudent to explore the acceptability and accessibility of the MAIDS questionnaire prior to any further validation analysis. A number of problems arose, specifically with individual items. The majority of the sample answered ‘yes’ to question 1 “I am good at listening” across all three time points (16/19, 14/15, and 14/14, respectively) suggesting that this was a demand characteristic. Question 6 “I wish I could be happy all the time” prompted all but 2 respondents to respond ‘yes’ (1 responded ‘no’ and 1 responded ‘do not know’) at baseline, 14/15 (93%) at 2-month follow-up, and 12/14 (86%) at the 6-month follow-up. Possible confusion was indicated regarding the responses for Q7 “I can find the right words to say that I am angry” and Q9 “I cannot find the right words to say I am angry”. At baseline, 7/19 respondents (37%) gave the same answer ‘yes’ to both. At 2 months, 6/15 respondents (40%) gave the same answer (a mixture of ‘yes’ and ‘no’) to both. At 6 months, 4/14 respondents (29%) gave the same answer to both (a mixture of ‘yes’ and ‘no’). Direct observation of participants’ responses to the questionnaire also suggested that constructs (e.g., ‘hot’, ‘cold’, ‘angry’) rather than the concept of awareness may have driven replies. Due to these issues, further reliability and validity analyses were not considered useful. Mean scores are shown in Table 3, but these should be considered with caution.

From a health economic evaluation perspective, it was of interest whether the included health-related quality of life outcome measures were appropriate for this study population. The individuals with ID were able to self-report on their health-related quality of life using the EQ-5D-Y and the ICECAP-A. However, the CHU-9D (a measure which is designed for children over the age of 7) resulted in difficulties leading to more missing data. One interesting observation was that mean participants’ self-reported health-related quality of life was consistently higher than mean proxy ratings across all time points on all outcome measures. As this was a very small sample, no formal statistical analysis was conducted. However, further investigation is warranted to assess the construct validity of measures in this population and level of agreement between proxy and self-report utility measurement.

Following the development of the UK SoF manual, the total costs to set up and deliver the intervention within the feasibility study were £55,361 (total set up costs £9276 plus total delivery costs of £46,085—see Appendix C (supplemental materials) for base case costing). This excludes the cost to adapt and develop the manual for a UK setting (estimated to be approximately £21,008 in research and initial development costs). Intervention setup costs included the initial therapist training (plus any associated staff backfill) and the purchase of therapist course materials. The initial training cost was £565 per therapist with a total of 16 therapists completing their training as part of the feasibility study. Course materials were purchased for therapists to use during the delivery of the intervention; these included the program manual, a mindfulness book, bean bags, and a tote storage bag at a total cost of £22.84 per therapist. Of the therapists trained in the study, ten therapists and one of the course trainers went on to deliver the intervention to nineteen individuals with ID and their carer, at a total cost of £46,085 for program delivery, equating to £2426 per participant. Sensitivity analysis which included the setup costs (training costs and course materials) attached to the therapists that delivered the intervention indicated that the program costs would rise to a total cost of £52,556 equating to £2766 per participant. The highest costs in the delivery of the program was the therapist time (including travel time) and costs associated with ongoing clinical and mindfulness supervision.

Resource use data for the previous 4 months was obtained from 19 study participants at baseline and 14 participants post intervention (2 months following baseline) and at the final follow up-at 6 months (post baseline). Table 5 below shows the summary of community-based contacts at baseline for the proceeding 4 months. This table shows the breadth and frequency of contacts that this group of individuals are receiving across formal community services. For these 19 study participants, community services equated to a total mean cost of £1176 (SD 1786.77) per person (over the 4-month period prior to the start of the study). At the end of the intervention during the 2-month follow-up, excluding the cost of the UK SoF intervention, mean resource use costs for 14 participants was £1367.83 (SD 1710.79) for the proceeding 4 months. At 6 months, the 10 participants followed up in the study showed they had received services with a mean cost per participant of £4063 (SD 7283.28). This was mainly made up of the costs of regular home help and family support worker visits. These data, however, are very skewed with a few participants receiving a great deal of input from these services and other participants none; they are reflected in the large standard deviation.

The mean cost per person of hospital-based services used (for the previous 4 months at each time point) was £108 (SD 250.82) at baseline, £197 (SD 328.59) post intervention, and £52 (SD 108.78) at 6-month follow-up. Very few participants accessed hospital-based services; for example, only one participant attended A&E (at baseline), two participants had been to an outpatient appointment at the 6-month follow-up, and there were no overnight hospital stays at any time point.

At baseline, four (of the 19) study participants were in paid employment; in all cases, this was minimum wage or below and on a part-time basis. In addition, at baseline, three of the individuals with ID out of 19 had engaged in some voluntary work with the number of people volunteering rising to six (of the 10 followed up) at the 6-month follow-up time point.

Retaining carers in the study proved challenging as noted earlier, as did the exclusion of participants with ID and ASD. The development of an appropriate mindfulness measure also proved difficult. It is suggested that any future research protocol should consider these issues. As this was a feasibility study, testing the effectiveness of the UK SoF intervention was not a primary aim (Bowen et al. 2009); although, there was evidence to suggest that there were reductions in reported anger and aggression in both the quantitative and the qualitative data (Griffith et al. 2019). Based on the feasibility outcomes of this study and the number of suggested adaptations to the protocol, it would seem sensible for future research to conduct a pilot clinical trial rather than developing a full RCT at this stage.