Evaluating the feasibility and effectiveness of self-monitoring of health among Samoan women: a randomized trial

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Erica Kocher
Mayur Desai
Anna Rivara
Take Naseri
Nicola Hawley


Samoa, Exercise, Body Mass Index, Psychosocial Factors, Self-monitoring


Objective: Self-monitoring technologies that help individuals track their health have proven effective in high-income countries but have not been widely tested or marketed in the Pacific islands. We conducted a pilot randomized controlled trial in Samoa to investigate the feasibility and acceptability of step-counters and digital scales.

Methods: The trial enrolled 44 Samoan women (31-40 years), without previously diagnosed chronic conditions (hypertension, diabetes, etc.), who reported motivation to become more physically active. After measuring daily step counts for one week in the absence of feedback, participants were randomly assigned to one of three groups for a four-week intervention period: 1) FitBit Zip® step-counter, 2) digital BodyTrace© scale, or 3) both devices. Outcomes of interest were device use, psychosocial indicators of health, daily step counts, and body mass index, measured at baseline and post-intervention.

Results: Participants who received scales used them a median of 5.5 times during the four-week intervention period. While FitBits were used a majority of days during the baseline period, there was significant decline in use during the intervention. In all groups, Health Locus of Control, Self-Efficacy for Exercise, and Weight Efficacy improved. However, while the Scale Only group reported improved health-related quality of life, the two groups that used FitBits either did not significantly change or significantly decreased in their assessments of this measure. No group demonstrated change in average daily step counts during the intervention; BMI increased among the two groups using the scales.

Conclusions: Results suggest that self-monitoring technologies are acceptable in Samoa and generally improve psychosocial indicators of health. Further research is necessary to assess their effectiveness as an intervention tool and to determine how best to sustain device use over time. The significant increase in BMI over the relatively short intervention period highlights the importance of developing effective intervention approaches in this setting.

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Hawley NL, Minster RL, Weeks DE, et al. Prevalence of adiposity and associated cardiometabolic risk factors in the Samoan genome-wide association study. American journal of human biology : the official journal of the Human Biology Council 2014; 26(4): 491-501.
2. Swinburn B, Ley S, Carmichael H, Plank L. Body size and composition in Polynesians. International Journal of Obesity 1999; 23: 1178-83.
3. Minster RL, Hawley NL, Su C-T, et al. A thrifty variant in CREBRF strongly influences body mass index in Samoans. Nature Genetics 2016; 48: 1049-54.
4. Wang C, Abbot L, Goodbody A, Hui W. Ideal body image and health status in low-income Pacific Islanders. Journal of Cultural Diversity 2002; 9(1): 12-22.
5. Tuagalu C. Young People’s Perceptions and Experiences of Physical Activity in Apia, Samoa. Pacific Health Dialog 2011; 17(1).
6. Hardin J. Everyday translation: health practitioners’ perspectives on obesity and metabolic disorders in Samoa. Critical Public Health 2014; 25(2): 125-38.
7. Popkin BM. Global nutrition dynamics: the world is shifting rapidly toward a diet linked with noncommunicable diseases. The American Journal of Clinical Nutrition 2006; 84(2): 289-98.
8. Keighley ED, McGarvey ST, Quested C, McCuddin C, Viali S, Maga Uo. Nutrition and health in modernizing Samoans: temporal trends and adaptive perspectives. In: Ohtsuka R, Ulijaszek SJ, eds. Health Change in the Asia-Pacific Region: Biocultural and Epidemiological Approaches. Cambridge; 2007.
9. Steinberg DM, Tate DF, Bennett GG, Ennett S, Samuel-Hodge C, Ward DS. The Efficacy of a Daily Self-Weighing Weight Loss Intervention Using Smart Scales and E-mail. Obesity 2013; 21: 1789-97.
10. Shuger SL, Barry VW, Sui X, et al. Electronic feedback in a diet- and physical activity-based lifestyle intervention for weight loss: a randomized controlled trial. International Journal of Behavioral Nutrition and Physical Activity 2011; 8(41).
11. Ross KM, Wing RR. Impact of Newer Self-Monitoring Technology and Brief Phone-Based Intervention on Weight Loss: A Randomized Pilot Study. Obesity 2016; 24: 1653-9.
12. Chiauzzi E, Rodarte C, DasMahapatra P. Patient-centered activity monitoring in the self-management of chronic health conditions. BMC Medicine 2015; 13(1): 77.
13. Whelan ME, Goode AD, Eakin EG, et al. Feasibility, effectiveness and cost-effectiveness of a telephone-based weight loss program delivered via a hospital outpatient setting. Transl Behav Med 2016; 6(3): 386-95.
14. Tudor-Locke C, Lutes L. Why Do Pedometers Work? Sports Medicine 2009; 39(12): 981-93.
15. Burke LE, Wang J, Sevick MA. Self-Monitoring in Weight Loss: A Systematic Review of the Literature. Journal of the American Dietetic Association 2011; 111: 92-102.
16. Engstrom JL, Paterson SA, Doherty A, Trabulsi M, Speer KL. Accuracy of Self-Reported Height and Weight in Women: An Integrative Review of the Literature. Journal of Midwifery & Women’s Health 2003; 48(5): 338-45.
17. Samoan Obesity, Lifestyle, and Genetic Adaptations Study Group. "Soifua Manuia" (Good Health) Study (Samoa). September 24 2019. https://publichealth.yale.edu/olaga/projects/good_health/.
18. Marcus BH, Rakowski W, Rossi JS. Assessing Motivational Readiness and Decision Making for Exercise. Health Psychology 1992; 11(4): 257-61.
19. BodyTrace Inc. BodyTrace scale: frequently asked questions. https://www.bodytrace.com/medical/faq.html.
20. Wallston KA, Wallson BS, DeVellis R. Development of the Multidimensional Health Locus of Control (MHLC Scales). Health Education Monographs 1978; 6(2): 160-70.
21. Clark MM, Abrams DB, Niaura RS, Eaton CA, Rossi JS. Self-Efficacy in Weight Management. Journal of Consulting and Clinical Psychology 1991; 59(9): 739-44.
22. Sallis JF, Pinski RB, Grossman RM, Patterson TL, Nader PR. The development of self-efficacy scales for health-related diet and exercise behaviors. Health Education Research 1988; 3(3): 283-92.
23. Darvall JN, Parker A, Story DA. Feasibility and Acceptability of Remotely Monitored Pedometer-Guided Physical Activity. Anaesthesia and Intensive Care 2016; 44(4): 501-6.
24. Zoellner J, Powers A, Avis-Williams A, Ndirangu M, Strickland E, Yadrick K. Compliance and Acceptability of Maintaining a 6-Month Pedometer Diary in a Rural, African American Community-Based Walking Intervention. Journal of Physical Activity and Health 2009; 6(4): 475-82.
25. Pekmezi D, Dunsiger S, Gaskins R, et al. Feasibility and Acceptability of Using Pedometers as an Intervention Tool for Latinas. Journal of Physical Activity and Health 2013; 10(3): 451-7.
26. Wallston BS, Wallston KA. Locus of Control and Health: A Review of the Literature. Health Education Monographs 1978; 6(2): 107-17.
27. Sniehotta FF, Scholz U, Schwarzer R. Bridging the intention–behaviour gap: Planning, self-efficacy, and action control in the adoption and maintenance of physical exercise. Psychology and Health 2005; 20(2): 143-60.
28. Calfas KJ, Sallis JF, Oldenburg B, Ffrench M. Mediators of Change in Physical Activity Following an Intervention in Primary Care: PACE. Preventive Medicine 1997; 26: 297-304.
29. Hardin J, McLennan AK, Brewis A. Body size, body norms and some unintended consequences of obesity intervention in the Pacific islands. Annals of human biology 2018; 45(3): 285-94.
30. Dionne MM, Yeudall F. Monitoring of Weight in Weight Loss Programs: A Double-Edged Sword? Journal of Nutrition Education and Behavior 2005; 37: 319-22.
31. Samoa Bureau of Statistics. Household Income and Expenditure Survey 2013/2014 Tabulation Report. Apia: Samoa Bureau of Statistics, 2016.