Glover Marewa, Nolte Marrit, Wagemakers Annemarie, McRobbie Hayden, Kruger Rozanne, Breier Bernhard H, Stephen Jane, Funaki-Tahifote Mafi, Shanthakumar Mathu
1School of Health Sciences, College of Health, Massey University, PO Box 89186, Torbay, Auckland, 0742 New Zealand.
2Health and Society, Wageningen University & Research, Wageningen, The Netherlands.
BMC Obes. 2019 Mar 4;6:6. doi: 10.1186/s40608-019-0228-6. eCollection 2019.
New Zealand Pacific and Māori populations measure disproportionately high on the international body mass index (BMI). Information is needed on what behavioural weight loss goals to recommend and how to attract and retain them in interventions. Our team weight loss competition trial for participants with a BMI ≥30 used cash prizes to incentivise completion of nine daily behaviour goals. This paper evaluates the theoretical merit of and adherence to these goals.
A qualitative component evaluation methodology was used. Trial data on team activity, demographics and anthropometric outcome data were extracted to determine frequency of daily goal completion by teams throughout the competition and to describe participant characteristics. T-tests were used to compare completion rates of the challenges, challenge completion by day of week and between weekdays and weekends. To examine adherence to the daily challenge activity over 24 weeks the total amount of completed challenges adjusted for number of active teams was plotted by week. A Body Shape Index (ABSI) was used to determine individual anthropometric change from baseline to 8, 16 and 24 weeks. Program documents were analysed to identify barriers to adherence and retention of participants.
Of 19 teams ( = 130) who began only five teams performed daily goals across the whole 24 weeks. Adherence was highest during the first 8 weeks. No difference in performance between goals was found suggesting they were equally viable, though tasks worth less points were performed more frequently. Goal completion was higher on weekdays. The behaviour goals appeared to have theoretical merit in that more members of high performing teams experienced a positive change in their ABSI.
Incentives offer a promising strategy for encouraging retention in weight loss interventions. This study suggests that participants in a competition will perform incentivised tasks. The findings however, are limited by missing data and high drop out of individuals and whole teams. Further research is needed on how to increase retention.
新西兰太平洋岛民和毛利人群体的国际身体质量指数（BMI）偏高。需要了解应推荐哪些行为减肥目标，以及如何在干预措施中吸引并留住这些人群。我们针对BMI≥30的参与者开展的团队减肥竞赛试验，使用现金奖励激励参与者完成九项日常行为目标。本文评估了这些目标的理论价值及目标依从性。
采用定性成分评估方法。提取团队活动、人口统计学和人体测量学结果数据的试验数据，以确定各团队在整个竞赛期间每日目标的完成频率，并描述参与者特征。使用t检验比较各项挑战的完成率、按星期几以及工作日和周末之间的挑战完成情况。为了检查在24周内对每日挑战活动的依从性，按周绘制了根据活跃团队数量调整后的完成挑战总量。使用身体形状指数（ABSI）确定从基线到第8、16和24周的个体人体测量变化。分析项目文件以确定参与者依从性和留存率的障碍。
在开始的19个团队（n = 130）中，只有5个团队在整个24周内完成了每日目标。依从性在最初8周最高。未发现各目标之间的表现存在差异，这表明它们同样可行，不过得分较低的任务完成得更频繁。工作日的目标完成率更高。行为目标似乎具有理论价值，因为表现出色的团队中更多成员的ABSI有积极变化。
激励措施为鼓励坚持减肥干预提供了一种有前景的策略。本研究表明，竞赛中的参与者会执行受激励的任务。然而，研究结果受到数据缺失以及个体和整个团队高退出率的限制。需要进一步研究如何提高留存率。
