Examining the feasibility of a full-scale trial of the TAKE 5 weight management intervention for adults with intellectual disabilities.

Background: Adults with intellectual disabilities experience equivalent or higher rates of obesity in comparison to the general population. This increases the risk for health conditions associated with adverse weight gain including cardiovascular disease and type II diabetes. Clinical guidelines on the management of obesity recommend multi-component interventions which include an energy deficit diet (EDD) of 600 kcal per day, support to increase physical activity and key behaviour change techniques including goal setting and self-monitoring to facilitate these healthy lifestyle changes. However, the current evidence base and provision of health services on the management of obesity in adults with intellectual disabilities is limited. A systematic review of multi-component weight management interventions was conducted and identified only seven randomised controlled trials of weight management interventions in adults with intellectual disabilities and obesity. The intervention components primarily focussed on a health education approach including diet, physical activity, and behaviour change techniques. However, no intervention adhered to clinical recommendations in terms of including an EDD, a weight maintenance intervention or investigating the long term efficacy of the intervention at 12 months. Meta-analyses revealed that post intervention (Weighted mean difference; WMD: -0.92kg; 95% CI -2.11kg, 0.28kg; p = 0.13) and at 12 months (WMD: -1.15 kg (95% CI -4.15 kg to 1.86 kg; p = 0.45), current multi-component weight management interventions are not more effective than no treatment. The results of this review illustrate that the current evidence base is insufficient to support multi-component weight management interventions focussed on a health education approach and therefore, future studies should investigate the efficacy of an alternative approach and the inclusion of an EDD to examine the efficacy of this approach to the management of obesity in adults with intellectual disabilities. Methods: The primary aim of this thesis was to add to the limited evidence base on multi-component weight management interventions in adults with intellectual disabilities by examining the feasibility of conducting a full-scale trial of a multi-component intervention, TAKE 5. TAKE 5 adheres to clinical recommendations on weight management and was specifically designed for adults with intellectual disabilities, and where applicable implemented with support from carers. The study design was a single blind cluster randomised controlled trial comparing two active interventions. The comparator intervention, WWToo, was based on a health education approach and consisted of multiple components focussed on diet, physical activity and behaviour change techniques. A multi-point recruitment strategy was piloted. Participants were recruited from multiple organisations, from specialist intellectual disabilities services, provider organisations and local day centres. Additional feasibility outcomes included retention rates and the fidelity and implementation of the intervention. The primary efficacy outcome was change in body weight at 12 months. Additional secondary outcomes included anthropometric outcomes (BMI, waist circumference, percentage body fat), objective measure of physical activity (time spent in light, moderate to vigorous intensity and total physical activity) and sedentary behaviour and health related quality of life. Results: The multi-point recruitment strategy was shown to be feasible and 50 participants were successfully recruited to the study. This study design was shown to be acceptable to adults with intellectual disabilities as retention to both interventions was high with 90% of participants completing the intervention. The TAKE 5 multi-component weight management intervention with support from carers led to significant reductions in weight, BMI, waist circumference and percentage body fat at six and 12 months. Furthermore, 50% of the participants in the TAKE 5 intervention achieved a clinically significant weight loss of 5% or greater of initial body weight in comparison to 21% of the participants in the WWToo intervention. Significant improvements in the above outcomes were not found in participants completing the WWToo intervention. A limitation of both interventions was the inability to engage participants in physical activity, reduce the sedentary lifestyle behaviours and improve health related quality of life of this population group. Both interventions were implemented as intended, and both interventions were shown to be feasible and accessible to all adults with varying levels in intellectual disabilities due to the social support provided by carers in implementing the interventions. Conclusion: This study is the first ever randomised controlled trial of a weight management intervention that adheres to clinical recommendations in adults with intellectual disabilities. This study provided evidence on the feasibility of this study design in adults with intellectual disabilities and demonstrated the acceptability of the EDD approach tailored to meet the needs of adults with intellectual disabilities. Furthermore, this study has provided preliminary evidence that an EDD may be an efficacious approach to weight management, and provided further evidence that current service provision based on health education approach is ineffective in the treatment of obesity in adults with intellectual disabilities. On the basis of these findings a future full-scale randomised controlled trial is necessary to confirm these findings and provide evidence on the optimum approach to weight management in this population group