Swendeman Dallas, Comulada Warren Scott, Koussa Maryann, Worthman Carol M, Estrin Deborah, Rotheram-Borus Mary Jane, Ramanathan Nithya
Department of Psychiatry and Biobehavioral Sciences, David Geffon School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.
Department of Anthropology, Emory University, Atlanta, GA, United States.
JMIR Mhealth Uhealth. 2018 Sep 21;6(9):e176. doi: 10.2196/mhealth.9378.
Multiple strategies can be used when self-monitoring diet, physical activity, and perceived stress, but no gold standards are available. Although self-monitoring is a core element of self-management and behavior change, the success of mHealth behavioral tools depends on their validity and reliability, which lack evidence. African American and Latina mothers in the United States are high-priority populations for apps that can be used for self-monitoring of diet, physical activity, and stress because the body mass index (BMI) of mothers typically increases for several years after childbirth and the risks of obesity and its' sequelae diseases are elevated among minority populations.
To examine the intermethod reliability and concurrent validity of smartphone-based self-monitoring via ecological momentary assessments (EMAs) and use of daily diaries for diet, stress, and physical activity compared with brief recall measures, anthropometric biomeasures, and bloodspot biomarkers.
A purposive sample (n=42) of primarily African American (16/42, 39%) and Latina (18/42, 44%) mothers was assigned Android smartphones for using Ohmage apps to self-monitor diet, perceived stress, and physical activity over 6 months. Participants were assessed at 3- and 6-month follow-ups. Recall measures included brief food frequency screeners, physical activity assessments adapted from the National Health and Nutrition Examination Survey, and the nine-item psychological stress measure. Anthropometric biomeasures included BMI, body fat, waist circumference, and blood pressure. Bloodspot assays for Epstein-Barr virus and C-reactive protein were used as systemic load and stress biomarkers. EMAs and daily diary questions assessed perceived quality and quantity of meals, perceived stress levels, and moderate, vigorous, and light physical activity. Units of analysis were follow-up assessments (n=29 to n=45 depending on the domain) of the participants (n=29 with sufficient data for analyses). Correlations, R statistics, and multivariate linear regressions were used to assess the strength of associations between variables.
Almost all participants (39/42, 93%) completed the study. Intermethod reliability between smartphone-based EMAs and diary reports and their corresponding recall reports was highest for stress and diet; correlations ranged from .27 to .52 (P<.05). However, it was unexpectedly low for physical activity; no significant associations were observed. Concurrent validity was demonstrated for diet EMAs and diary reports on systolic blood pressure (r=-.32), C-reactive protein level (r=-.34), and moderate and vigorous physical activity recalls (r=.35 to.48), suggesting a covariation between healthy diet and physical activity behaviors. EMAs and diary reports on stress were not associated with Epstein-Barr virus and C-reactive protein level. Diary reports on moderate and vigorous physical activity were negatively associated with BMI and body fat (r=-.35 to -.44, P<.05).
Brief smartphone-based EMA use may be valid and reliable for long-term self-monitoring of diet, stress, and physical activity. Lack of intermethod reliability for physical activity measures is consistent with prior research, warranting more research on the efficacy of smartphone-based self-monitoring of self-management and behavior change support.
在自我监测饮食、身体活动及感知压力时可采用多种策略，但尚无金标准。尽管自我监测是自我管理和行为改变的核心要素，但移动健康行为工具的成功取决于其有效性和可靠性，而目前缺乏相关证据。美国非裔和拉丁裔母亲是可用于饮食、身体活动和压力自我监测应用程序的重点人群，因为产后母亲的体重指数（BMI）通常会在数年内上升，且少数族裔人群肥胖及其后遗症的风险较高。
通过生态瞬时评估（EMA）和使用日常日记对饮食、压力和身体活动进行基于智能手机的自我监测，并与简短回忆测量、人体测量生物指标和血斑生物标志物进行比较，以检验其方法间的可靠性和同时效度。
选取了一个有目的的样本（n = 42），主要为非裔美国人（16/42，39%）和拉丁裔（18/42，44%）母亲，为她们配备安卓智能手机，使用Ohmage应用程序在6个月内自我监测饮食、感知压力和身体活动。在3个月和6个月的随访时对参与者进行评估。回忆测量包括简短食物频率筛查、改编自国家健康与营养检查调查的身体活动评估以及九项心理压力测量。人体测量生物指标包括BMI、体脂、腰围和血压。对爱泼斯坦 - 巴尔病毒和C反应蛋白的血斑检测用作全身负荷和压力生物标志物。EMA和日常日记问题评估了感知到的饮食质量和数量、感知压力水平以及中度、剧烈和轻度身体活动。分析单位是参与者的随访评估（根据领域不同，n = 29至n = 45）（n = 29有足够数据进行分析）。使用相关性、R统计和多元线性回归来评估变量之间关联的强度。
几乎所有参与者（39/42，93%）完成了研究。基于智能手机的EMA与日记报告及其相应回忆报告之间的方法间可靠性在压力和饮食方面最高；相关性范围为0.27至0.52（P <.05）。然而，身体活动方面的可靠性出乎意料地低；未观察到显著关联。饮食EMA和日记报告在收缩压（r = -0.32）、C反应蛋白水平（r = -0.34）以及中度和剧烈身体活动回忆（r = 0.35至0.48）方面显示出同时效度，表明健康饮食和身体活动行为之间存在协变关系。关于压力的EMA和日记报告与爱泼斯坦 - 巴尔病毒和C反应蛋白水平无关。关于中度和剧烈身体活动的日记报告与BMI和体脂呈负相关（r = -0.35至 -0.44，P <.05）。
基于智能手机的简短EMA使用对于饮食、压力和身体活动的长期自我监测可能是有效且可靠的。身体活动测量缺乏方法间可靠性与先前研究一致，需要对基于智能手机的自我管理和行为改变支持的自我监测功效进行更多研究。
