Ecological Momentary Assessment and Childhood Obesity


Ecological Momentary Assessment (EMA) was developed for the benefit of researchers looking for a better way to collect data, and it helps patients, too. The particular subsets of patients we are interested in are overweight and obese children and adolescents. Once EMA had been shown to benefit adults health professionals were eager to employ it with younger people, and the signs are encouraging.

In this kind of research, the subjects agree to perform certain actions, and everything depends on the whether they actually follow through on what they’ve signed up for. A better compliance rate means better data for the researchers and better results for the subjects, who are presumably trying to accomplish something, like an improved state of health.

Compliance rates are influenced by comfort and familiarity with the technology. Most kids are adept at using technological devices like cell phones and activity monitors.

When the patients are children and teens, EMA is attractive for very good reasons. It can stand alone as a treatment modality, without bringing pharmaceuticals into the picture. Also, it is not surgery.

EMA’s Adaptability

All studies have different needs and constraints, so a dozen researchers might design a dozen different protocols to come at the same problem from different directions. EMA’s advantage is that it can cover a lot of angles, and is almost infinitely adaptable.

A Children’s Hospital of Pittsburgh research team discovered that most attempts to quell pediatric obesity have disappointingly unspectacular results. According to the research team:

EMA methodology may assist weight-loss efforts by clarifying the antecedents of participants’ eating behavior, by improving accuracy of self-monitoring and by specifying the temporal relationships of the target behaviors. A second, equally important value of the EMA approach is its ecological validity, that is, that its results can be generalized by its ability to perform measurements in the real world: the authentic surroundings of the respondents.

Carried out by the Weight Management Center, a 2009 study with 20 subjects hoped to assess the possibility of using EMA to “examine important domains relevant to interregulatory health processes in overweight adolescent females.” Each participant wore an activity monitor, which senses motion and other physical states, and also transmits and records information about physical activity (PA), sleep cycles, and other variables.

The device can be worn on the wrist, waist, ankle or thigh. The authors say:

The intervention consisted of four weekly, four bi-weekly, and three monthly individual sessions. Information focusing on nutrition, PA, and behavior change was presented in ~45-min sessions using cognitive–behavioral therapy and motivational interviewing followed by ~30 min of PA.

Participants received calls from a trained staff member for three extended weekends across the intervention. Participants were called twice on weekdays and four times on weekends for a total of 14 calls between 4 PM Thursday and 9 PM Monday. Each call consisted of a brief structured interview to evaluate current eating, PA, affect, and social context and lasted between 5 and 10 min.

Medicine and health promotion are related fields, of course. It makes sense that the technologies of information and communications are important to both of them, especially when it comes to data collection. As we have seen, EMA takes snapshots of a person’s daily life, randomly, or at crucial times (like deciding to go off the rails and eat everything that doesn’t eat you first), and ties them to other contemporaneous phenomena.

EMA tracks several factors at once, and every scrap of data can be marshaled into an algorithm. There are physical measurements like heart rate, and mental/emotional events are documented the moment they bubble up in the brain. Also, the subject does not have to remember past events. The immediacy, or “momentary” nature of the reportage, is a feature.

Your responses and feedback are welcome!

Source: “Utilizing Ecological Momentary Assessment in Pediatric Obesity to Quantify Behavior, Emotion, and Sleep,”, December 2009
Photo via Visualhunt

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