A NIH-funded prospective cohort study will evaluate behavioural, psychosocial and environmental predictors of weight loss after bariatric surgery using a multi-sensor platform that integrates objective sensors and self-report information collected via smartphone in real-time in patients’ natural environment. The outline of the study was published in the paper, ‘Multi-sensor ecological momentary assessment of behavioural and psychosocial predictors of weight loss following bariatric surgery: study protocol for a multi-centre prospective longitudinal evaluation’, by researchers from the Miriam Hospital/Warren Alpert Medical School of Brown University and Beth Israel Deaconess Medical Center.

The study investigators write that there is little understanding of the psychosocial and environmental factors that impact outcomes from bariatric surgery. Therefore, this study is planning to recruit 100 adult bariatric surgery patients (ages 21–70) use the multi-sensor platform at pre-operative baseline, three-, six-, and 12-months post-operatively, to assess recommended behaviours (eg, meal frequency, physical activity), psychosocial indicators with prior evidence of an association with surgical outcomes (eg, mood/depression) and key environmental factors (eg, type/quality of food environment). Weight will also be measured at each assessment point.

The study will utilise the ecological momentary assessment (EMA) method - by which participants are prompted to give in-the-moment reports on selected behaviours, cognitive/emotional states and environmental conditions several times throughout the day (usually using mobile phones). In addition, the researchers will use multi-method measurement approach with wearable sensors that connect to smartphones in real-time making it possible to obtain continuous, objective behavioural measurements in an individual’s natural environment.

“By combining EMA with objective sensors, it is possible to obtain more valid and reliable estimates of behavioural patterns that can be further enriched by additional contextual information,” the write. “For example, accelerometry, a well-accepted method for objectively assessing physical activity, can be enhanced with EMA questions delivered by smartphone to assess type of exercise, context, motivational factors, and barriers (all of which accelerometry alone cannot provide).”

In summary, the researchers configured an established EMA platform to allow for integration of: 1) direct, sensor-based measures of energy balance behaviors (ActiGraph Link) to measure physical activity, sedentary behaviour and sleep; Bite Counter to measure eating behaviour), and 2) self-report surveys administered several times daily via smartphone to capture subjective reports of other behaviours and experiences (Figure 1).

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Figure 1: EMA System and Components for a depiction of the multi-sensor measurement tools

“As behavioural factors are increasingly recognized as contributors to bariatric surgery outcomes, the current study is critical for identifying factors and contexts that influence behavior among individuals who have undergone bariatric surgery,” the authors concluded. “…Data and methods from the current study are also expected to provide a foundation for subsequent trials funded by NIH to examine behaviours that influence bariatric surgery outcomes. Overall, this programme of research will contribute significantly to evidence-based clinical care for bariatric surgery patients.”

To access this paper, please click here [2]