RESUMO
BACKGROUND: Being overweight or obese following breast cancer diagnosis can increase cancer recurrence and mortality, so effective interventions for weight loss in this group could enhance survival. A pilot randomised controlled trial was conducted to assess whether a weight loss programme comprising generic Weight Watchers® referral offered to women treated for breast cancer with or without additional breast cancer-tailored dietetic support is feasible and shows promise for improving weight and quality of life (QoL). METHODS: Participants were randomly allocated to 3 groups: Weight Watchers® referral (for 12 sessions of meetings and digital tools) plus 5 breast cancer-tailored dietitian-led group support sessions (WW Plus: n = 14), Weight Watchers® referral only (WW: n = 16) or control (Weight Watchers® referral after 3 months, n = 15). Feasibility was assessed based on retention rate, recruitment and randomisation process, meeting attendance, suitability of the setting and outcome measurement tools, unintended consequences, cost and observations of the dietetic sessions. Outcomes were measured at 0, 3 ('trial exit') and 12 months post intervention. RESULTS: The response rate to the invitation was 43% (140/327) of whom 58 were eligible and 45 (median age 61.0 years; body mass index 30.2 kg/m2) were randomised. Data from 38 (84%) and 30 (67%) participants were available at trial exit and 12 months respectively. Feasibility issues included slow recruitment process, lack of blinding throughout, weighing scales not measuring > 150 kg, lack of clear instructions for completing QoL questionnaire and workload and time pressures in delivering dietetic sessions. Participants had good attendance rate at group meetings and no serious unintended consequences were reported. WW Plus was most expensive to run. Mean (95% CI) weight change at trial exit was - 3.67 kg (- 5.67, - 2.07) in WW Plus, - 6.03 kg (- 7.61, - 4.44) in WW group and + 0.19 kg (- 1.45, + 1.83) in control group. About 40% of the WW Plus, 64% of the WW group and 56% of the control group lost ≥ 5% of their baseline weight by 12 months. All groups showed promise for improving QoL at trial exit but only the WW group maintained significant improvements from baseline at 12 months. CONCLUSIONS: The trial procedures were feasible, with some modifications. This pilot trial indicates the benefits of providing free WW vouchers for weight loss maintenance and improving QoL but provided no evidence that including additional dietetic support would add any extra value. Further research with WW with long-term follow-up should be undertaken to assess weight loss sustainability and benefit on health outcomes in this patient group. TRIAL REGISTRATION: ISRCTN-29623418.
RESUMO
BACKGROUND: Non-retention of participants seriously affects the credibility of clinical trial results and significantly reduces the potential of a trial to influence clinical practice. Non-retention can be defined as instances where participants leave the study prematurely. Examples include withdrawal of consent and loss to follow-up and thus outcome data cannot be obtained. The majority of existing interventions targeting retention fail to describe any theoretical basis for the observed improvement, or lack of improvement. Moreover, most of these interventions lack involvement of participants in their conception and/or design, raising questions about their relevance and acceptability. Many of the causes of non-retention involve people performing a behaviour (e.g. not returning a questionnaire). Behaviour change is difficult, and the importance of a strong theoretical basis for interventions that aim to change behaviour is increasingly recognised. This research aims to develop and pilot theoretically informed, participant-centred, evidence-based behaviour change interventions to improve retention in trials. METHODS: This research will generate data through semi-structured interviews on stakeholders' perspectives of the reasons for trial non-retention. It will identify perceived barriers and enablers to trial retention using the Theoretical Domains Framework. The intervention development work will involve identification of behaviour change techniques, using recognised methodology, and co-production of retention interventions through discussion groups with end-users. An evaluation of intervention acceptability and feasibility will be conducted in focus groups. Finally, a ready-to-use evaluation framework to deploy in Studies Within A Trial as well as an explanatory retention framework will be developed for identifying and tackling modifiable issues to improve trial retention. DISCUSSION: We believe this to be one of the first studies to apply a theoretical lens to the development of interventions to improve trial retention that have been informed by, and are embedded within, participants' experiential accounts. By developing and identifying priority interventions this study will support efforts to reduce research waste.
