Stanford Prevention Research Center, Stanford University School of Medicine, Stanford, CA, United States.
JMIR Mhealth Uhealth. 2016 May 18;4(2):e51. doi: 10.2196/mhealth.5146.
Mobile apps present a potentially cost-effective tool for delivering behavior change interventions at scale, but no known studies have tested the efficacy of apps as a tool to specifically increase vegetable consumption among overweight adults.
The purpose of this pilot study was to assess the initial efficacy and user acceptability of a theory-driven mobile app to increase vegetable consumption.
A total of 17 overweight adults aged 42.0 (SD 7.3) years with a body mass index (BMI) of 32.0 (SD 3.5) kg/m(2) were randomized to the use of Vegethon (a fully automated theory-driven mobile app enabling self-monitoring of vegetable consumption, goal setting, feedback, and social comparison) or a wait-listed control condition. All participants were recruited from an ongoing 12-month weight loss trial (parent trial). Researchers who performed data analysis were blinded to condition assignment. The primary outcome measure was daily vegetable consumption, assessed using an adapted version of the validated Harvard Food Frequency Questionnaire administered at baseline and 12 weeks after randomization. An analysis of covariance was used to assess differences in 12-week vegetable consumption between intervention and control conditions, controlling for baseline. App usability and satisfaction were measured via a 21-item post-intervention questionnaire.
Using intention-to-treat analyses, all enrolled participants (intervention: 8; control: 9) were analyzed. Of the 8 participants randomized to the intervention, 5 downloaded the app and logged their vegetable consumption a mean of 0.7 (SD 0.9) times per day, 2 downloaded the app but did not use it, and 1 never downloaded it. Consumption of vegetables was significantly greater among the intervention versus control condition at the end of the 12-week pilot study (adjusted mean difference: 7.4 servings; 95% CI 1.4-13.5; P=.02). Among secondary outcomes defined a priori, there was significantly greater consumption of green leafy vegetables, cruciferous vegetables, and dark yellow vegetables (adjusted mean difference: 2.6, 1.6, and 0.8 servings; 95% CI 0.1-5.0, 0.1-3.2, and 0.3-1.4; P=.04, P=.04, and P=.004, respectively). Participants reported positive experiences with the app, including strong agreement with the statements "I have found Vegethon easy to use" and "I would recommend Vegethon to a friend" (mean 4.6 (SD 0.6) and 4.2 (SD 0.8), respectively, (on a 5-point scale).
Vegethon demonstrated initial efficacy and user acceptability. A mobile app intervention may be useful for increasing vegetable consumption among overweight adults. The small sample size prevented precise estimates of effect sizes. Given the improved health outcomes associated with increases in vegetable consumption, these findings indicate the need for larger, longer-term evaluations of Vegethon and similar technologies among overweight adults and other suitable target groups.
ClinicalTrials.gov NCT01826591; https://clinicaltrials.gov/ct2/show/NCT01826591 (Archived by WebCite at http://www.webcitation.org/6hYDw2AOB).
移动应用程序为大规模提供行为改变干预措施提供了一种潜在的具有成本效益的工具，但目前还没有已知的研究测试应用程序作为一种专门增加超重成年人蔬菜摄入量的工具的功效。
本初步研究旨在评估一款基于理论的移动应用程序增加蔬菜摄入量的初步功效和用户接受度。
共有 17 名超重成年人（年龄 42.0 [SD 7.3] 岁），体重指数（BMI）为 32.0 [SD 3.5] kg/m2，随机分为使用 Vegethon（一个完全自动化的基于理论的移动应用程序，能够自我监测蔬菜摄入量、设定目标、提供反馈和进行社会比较）或候补对照组。所有参与者均从正在进行的为期 12 个月的减肥试验（母试验）中招募。进行数据分析的研究人员对条件分配情况不知情。主要结局指标是每日蔬菜摄入量，使用经过验证的哈佛食物频率问卷的改编版本进行评估，在基线和随机分组后 12 周进行评估。采用协方差分析评估干预组和对照组在 12 周蔬菜摄入量方面的差异，控制基线。通过 21 项干预后问卷调查评估应用程序的可用性和满意度。
使用意向治疗分析，所有入组的参与者（干预组：8；对照组：9）均进行了分析。在随机分配到干预组的 8 名参与者中，5 名参与者平均每天记录蔬菜摄入量 0.7（SD 0.9）次，2 名参与者下载了应用程序但未使用，1 名参与者从未下载过。在 12 周的初步研究结束时，干预组的蔬菜摄入量明显高于对照组（调整后的平均差异：7.4 份；95%CI 1.4-13.5；P=.02）。在预先定义的次要结局中，绿叶蔬菜、十字花科蔬菜和深黄色蔬菜的摄入量明显增加（调整后的平均差异：2.6、1.6 和 0.8 份；95%CI 0.1-5.0、0.1-3.2 和 0.3-1.4；P=.04、P=.04 和 P=.004）。参与者对应用程序的体验表示肯定，包括对“我发现 Vegethon 易于使用”和“我会向朋友推荐 Vegethon”这两个陈述的强烈认同（平均值分别为 4.6（SD 0.6）和 4.2（SD 0.8），（五分制）。
Vegethon 显示出初步的功效和用户接受度。移动应用程序干预可能有助于增加超重成年人的蔬菜摄入量。由于蔬菜摄入量的增加与改善健康结果相关，因此这些发现表明需要在超重成年人和其他合适的目标群体中对 Vegethon 和类似技术进行更大、更长时间的评估。
ClinicalTrials.gov NCT01826591；https://clinicaltrials.gov/ct2/show/NCT01826591（由 WebCite 存档；http://www.webcitation.org/6hYDw2AOB）。
