Text messaging and financial incentives to encourage weight loss in men with obesity: the Game of Stones feasibility RCT

Effectiveness and cost-effectiveness of text messages with or without endowment incentives for weight management in men with obesity (Game of Stones): study protocol for a randomised controlled trial

BACKGROUND

Obesity increases the risk of type 2 diabetes, heart disease, stroke, mobility problems and some cancers, and its prevalence is rising. Men engage less than women in existing weight loss interventions. Game of Stones builds on a successful feasibility study and aims to find out if automated text messages with or without endowment incentives are effective and cost-effective for weight loss at 12 months compared to a waiting list comparator arm in men with obesity.

METHODS

A 3-arm, parallel group, assessor-blind superiority randomised controlled trial with process evaluation will recruit 585 adult men with body mass index of 30 kg/m² or more living in and around three UK centres (Belfast, Bristol, Glasgow), purposively targeting disadvantaged areas. Intervention groups: (i) automated, theory-informed text messages daily for 12 months plus endowment incentives linked to verified weight loss targets at 3, 6 and 12 months; (ii) the same text messages and weight loss assessment protocol; (iii) comparator group: 12 month waiting list, then text messages for 3 months. The primary outcome is percentage weight change at 12 months from baseline. Secondary outcomes at 12 months are as follows: quality of life, wellbeing, mental health, weight stigma, behaviours, satisfaction and confidence. Follow-up includes weight at 24 months. A health economic evaluation will measure cost-effectiveness over the trial and over modelled lifetime: including health service resource-use and quality-adjusted life years. The cost-utility analysis will report incremental cost per quality-adjusted life years gained. Participant and service provider perspectives will be explored via telephone interviews, and exploratory mixed methods process evaluation analyses will focus on mental health, multiple long-term conditions, health inequalities and implementation strategies.

DISCUSSION

The trial will report whether text messages (with and without cash incentives) can help men to lose weight over 1 year and maintain this for another year compared to a comparator group; the costs and benefits to the health service; and men's experiences of the interventions. Process analyses with public involvement and service commissioner input will ensure that this open-source digital self-care intervention could be sustainable and scalable by a range of NHS or public services.

TRIAL REGISTRATION

ISRCTN 91974895 . Registered on 14/04/2021.

A systematic review examining socioeconomic factors in trials of interventions for men that report weight as an outcome

Weight management interventions designed specifically for men have become more common, but the extent to which socioeconomic factors are considered in trials of these interventions is unclear. We synthesized study characteristics, methods, and reporting of interventions with a behavioral component for men that report weight as an outcome, to establish the extent to which socioeconomic factors are considered during intervention design, conduct, and reporting. A comprehensive search was conducted on Medline, Embase, PsycINFO, and CENTRAL for studies published from January 2000 to July 2021. Thirty-six trials were included. Educational attainment (n = 24) was the most frequently reported socioeconomic characteristic, followed by working status (n = 14) and area level deprivation (n = 12). Seven studies did not report any socioeconomic characteristics. Most studies (n = 20) did not mention the socioeconomic profile of their samples in relation to study strengths or limitations. Few (n = 4) consulted with men from lower socioeconomic groups during intervention design. One study examined potential differential intervention effects across socioeconomic groups, with most not powered to do so. Recent feasibility trials (n = 3) targeting specific socioeconomic groups suggest a potential nascent towards a greater consideration of factors related to equity. To best inform public health policy related to health inequalities, greater consideration of socioeconomic factors is required in trials of men's weight management interventions.

Recruiting men from across the socioeconomic spectrum via GP registers and community outreach to a weight management feasibility randomised controlled trial

Background

Men, particularly those living in disadvantaged areas, are less likely to participate in weight management programmes than women despite similar levels of excess weight. Little is known about how best to recruit men to weight management interventions. This paper describes patient and public involvement in pre-trial decisions relevant to recruitment and aims to report on recruitment to the subsequent men-only weight management feasibility trial, including the: i) acceptability and feasibility of recruitment; and ii) baseline sample characteristics by recruitment strategy.

Methods

Men with BMI ≥30 kg/m² and/or waist circumference ≥ 40 in. were recruited to the feasibility trial via two strategies; community outreach (venue information stands and word of mouth) and GP letters, targeting disadvantaged areas. Recruitment activities (e.g. letters sent, researcher venue hours) were recorded systematically, and baseline characteristics questionnaire data collated. Qualitative interviews (n = 50) were conducted three months post-recruitment. Analyses and reporting followed a complementary mixed methods approach.

Results

105 men were recruited within four months (community n = 60, GP letter n = 45). Community outreach took 2.3 recruiter hours per participant and GP letters had an opt-in rate of 10.2% (n = 90/879). More men were interested than could be accommodated. Most participants (60%) lived in more disadvantaged areas. Compared to community outreach, men recruited via GP letters were older (mean = 57 vs 48 years); more likely to report an obesity-related co-morbidity (87% vs 44%); and less educated (no formal qualifications, 32% vs 10%, degree educated 11% vs 41%). Recruitment strategies were acceptable, a sensitive approach and trusting relationships with recruiters valued, and the ‘catchy’ study name drew attention.

Conclusions

Targeted community outreach and GP letters were acceptable strategies that successfully recruited participants to a men-only weight management feasibility trial. Both strategies engaged men from disadvantaged areas, a typically underserved population. Using two recruitment strategies produced samples with different health risk profiles, which could add value to research where either primary or secondary prevention is of interest. Further work is required to examine how these strategies could be implemented and sustained in practice.

Trial registration

ClinicalTrials.gov: NCT03040518, 2nd February 2017.