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Author Notes:

Corresponding Author: Nithya Ramanathan, PhD. Department of Computer Science, University of California, Los Angeles. 10920 Wilshire Boulevard, Los Angeles, CA, 90024. Phone: 1 213 915 6729; Fax: 1 213 302 5247; Email: nithyaar@gmail.com

Conflicts of Interest: None declared.


Research Funding:

This work was sponsored by NHLBI Grant 5RC1HL099556 to the last author (PI) and the co-authors as co-investigators.

Comulada’s time was also supported by NIMH Grant K01MH089270.

Swendeman’s time was supported by a scholar award from the William T Grant Foundation (#180039).

Other support was provided by: the Center for HIV Identification, Prevention, and Treatment (CHIPTS) NIMH Grant MH58107; the UCLA Center for AIDS Research (CFAR) Grant 5P30AI028697; and the National Center for Advancing Translational Sciences through UCLA CSTI Grant UL1TR000124.


  • self-monitoring
  • mHealth
  • diet
  • physical activity
  • stress
  • multi-method
  • mobile phones
  • C-reactive protein

Validity and Reliability of Brief Smartphone Self-Monitoring of Diet, Stress, and Physical Activity in a Diverse Sample of Mothers


Journal Title:

JMIR mHealth and uHealth


Volume 6, Number 9


, Pages 176-None

Type of Work:

Article | Final Publisher PDF


Background: 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. Objective: 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. Methods: 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, R2 statistics, and multivariate linear regressions were used to assess the strength of associations between variables. Results: 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). Conclusions: 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.

Copyright information:

©Dallas Swendeman, Warren Scott Comulada, Maryann Koussa, Carol M Worthman, Deborah Estrin, Mary Jane Rotheram-Borus, Nithya Ramanathan.

This is an Open Access work distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/).
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