MRC Human Nutrition Research, Cambridge, UK; MRC Epidemiology Unit, University of Cambridge, Cambridge, UK.
MRC Biostatistics Hub for Trials Methodology Research, University of Cambridge, Cambridge, UK; Cancer Research UK and UCL Cancer Trials Centre, University College London, London, UK.
Lancet. 2017 Jun 3;389(10085):2214-2225. doi: 10.1016/S0140-6736(17)30647-5. Epub 2017 May 3.
Evidence exist that primary care referral to an open-group behavioural programme is an effective strategy for management of obesity, but little evidence on optimal intervention duration is available. We aimed to establish whether 52-week referral to an open-group weight-management programme would achieve greater weight loss and improvements in a range of health outcomes and be more cost-effective than the current practice of 12-week referrals.
In this non-blinded, parallel-group, randomised controlled trial, we recruited participants who were aged 18 years or older and had body-mass index (BMI) of 28 kg/m or higher from 23 primary care practices in England. Participants were randomly assigned (2:5:5) to brief advice and self-help materials, a weight-management programme (Weight Watchers) for 12 weeks, or the same weight-management programme for 52 weeks. We followed-up participants over 2 years. The primary outcome was weight at 1 year of follow-up, analysed with mixed-effects models according to intention-to-treat principles and adjusted for centre and baseline weight. In a hierarchical closed-testing procedure, we compared combined behavioural programme arms with brief intervention, then compared the 12-week programme and 52-week programme. We did a within-trial cost-effectiveness analysis using person-level data and modelled outcomes over a 25-year time horizon using microsimulation. This study is registered with Current Controlled Trials, number ISRCTN82857232.
Between Oct 18, 2012, and Feb 10, 2014, we enrolled 1269 participants. 1267 eligible participants were randomly assigned to the brief intervention (n=211), the 12-week programme (n=528), and the 52-week programme (n=528). Two participants in the 12-week programme had been found to be ineligible shortly after randomisation and were excluded from the analysis. 823 (65%) of 1267 participants completed an assessment at 1 year and 856 (68%) participants at 2 years. All eligible participants were included in the analyses. At 1 year, mean weight changes in the groups were -3·26 kg (brief intervention), -4·75 kg (12-week programme), and -6·76 kg (52-week programme). Participants in the behavioural programme lost more weight than those in the brief intervention (adjusted difference -2·71 kg, 95% CI -3·86 to -1·55; p<0·0001). The 52-week programme was more effective than the 12-week programme (-2·14 kg, -3·05 to -1·22; p<0·0001). Differences between groups were still significant at 2 years. No adverse events related to the intervention were reported. Over 2 years, the incremental cost-effectiveness ratio (ICER; compared with brief intervention) was £159 per kg lost for the 52-week programme and £91 per kg for the 12-week programme. Modelled over 25 years after baseline, the ICER for the 12-week programme was dominant compared with the brief intervention. The ICER for the 52-week programme was cost-effective compared with the brief intervention (£2394 per quality-adjusted life-year [QALY]) and the 12-week programme (£3804 per QALY).
For adults with overweight or obesity, referral to this open-group behavioural weight-loss programme for at least 12 weeks is more effective than brief advice and self-help materials. A 52-week programme produces greater weight loss and other clinical benefits than a 12-week programme and, although it costs more, modelling suggests that the 52-week programme is cost-effective in the longer term.
National Prevention Research Initiative, Weight Watchers International (as part of an UK Medical Research Council Industrial Collaboration Award).
有证据表明，将肥胖患者转介至开放群组行为方案是管理肥胖的有效策略，但关于最佳干预持续时间的证据有限。我们旨在确定将患者转介至开放群组体重管理方案 52 周是否比目前的 12 周转介更能实现更大的体重减轻和改善一系列健康结果，并具有更高的成本效益。
在这项非盲、平行组、随机对照试验中，我们从英国 23 个初级保健实践中招募了年龄在 18 岁及以上、体重指数（BMI）为 28kg/m2 或更高的参与者。参与者被随机分配（2:5:5）接受简短建议和自助材料、52 周的体重管理计划（Weight Watchers）或相同的体重管理计划 12 周。我们在 2 年内对参与者进行了随访。主要结局是 1 年随访时的体重，根据意向治疗原则和中心及基线体重进行混合效应模型分析。在分层封闭测试程序中，我们将联合行为计划组与简短干预进行比较，然后比较 12 周方案和 52 周方案。我们使用个人水平数据进行了试验内成本效益分析，并使用微模拟对 25 年的时间范围内的结果进行了建模。本研究在当前对照试验注册，编号为 ISRCTN82857232。
在 2012 年 10 月 18 日至 2014 年 2 月 10 日期间，我们招募了 1269 名参与者。1267 名符合条件的参与者被随机分配至简短干预组（n=211）、12 周方案组（n=528）和 52 周方案组（n=528）。12 周方案组的两名参与者在随机分组后不久被发现不符合条件，因此被排除在分析之外。1267 名符合条件的参与者中有 1267 名（823 名）在 1 年时进行了评估，856 名（68%）在 2 年时进行了评估。所有符合条件的参与者均纳入分析。在 1 年时，各组的体重变化平均值为-3.26kg（简短干预组）、-4.75kg（12 周方案组）和-6.76kg（52 周方案组）。接受行为方案的参与者比接受简短干预的参与者体重减轻更多（调整差异-2.71kg，95%CI-3.86 至-1.55；p<0.0001）。52 周方案比 12 周方案更有效（-2.14kg，-3.05 至-1.22；p<0.0001）。在 2 年时，组间差异仍然显著。没有报告与干预相关的不良事件。在 2 年内，增量成本效益比（ICER；与简短干预相比）为 52 周方案每减轻 1kg 体重花费 159 英镑，12 周方案每减轻 1kg 体重花费 91 英镑。基于基线后 25 年的建模，12 周方案的 ICER 与简短干预相比占优。52 周方案与简短干预（每质量调整生命年花费 2394 英镑）和 12 周方案（每质量调整生命年花费 3804 英镑）相比具有成本效益。
对于超重或肥胖的成年人，将其转介至这种开放群组行为减肥方案至少 12 周比提供简短建议和自助材料更有效。52 周方案比 12 周方案产生更大的体重减轻和其他临床益处，尽管成本更高，但建模表明，从长期来看，52 周方案具有成本效益。
国家预防研究倡议、Weight Watchers International（作为英国医学研究理事会工业合作奖的一部分）。
