Validating Accelerometers to Study Physical Activity of Toddlers

Study Overview
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Brief Summary
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One way to assess impacts of nutrition supplements to health is to measure physical activity. Physical activity can be measured with small devices called accelerometers. Before they can be used, the devices need to be validated in the population in question. Objectives of this study are to test accelerometers in field conditions and validate their use in 16-18 months old Malawian toddlers. This study does not have a pre-set hypothesis.

Detailed Description
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Accelerometers have not been validated in children under 2 years of age. In this study 50 toddlers from Lungwena will be recruited. The participants will wear an ActiGraph GT3X+ -accelerometer fitted on their waist with an elastic belt for 7 days. During the measuring, they will have two videotaped one-hour activity observations while wearing and additional accelerometer device fitted on their ankle. The output from the two devices will be compared to observed activity classified with CPAF-method.

Official Title
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Validating the Use of Accelerometers for the Study of Physical Activity Among Young Malawian Toddlers

Conditions
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Motor Activity

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: signed informed consent from at least one guardian age 16.00 months to 17.99 months availability during the period of the study Exclusion Criteria: any guardian reported or observed illness that limits child's physical activity a condition reported by the guardian that limits child's activity co-operate in the study wasting (weight-for-height < 2 SD) concurrent participation in any clinical trial with an intervention

Ages Eligible for Study
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Minimum Age: 16 Months
Maximum Age: 18 Months

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Study group<br>Healthy children | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Feasibility/acceptability | Proportion of participants (%) of wearing the accelerometer device for 4 days, 6 hours per day (defined from the accelerometer output data). | 7-day accelerometer measurement | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cut-off point values for sedentary, light, moderate, and vigorous activity | Videotaped observation of physical activity is classified by CPAF-method. Vector magnitude of the ActiGraph device attached to hip is compared to this gold standard and cut-off point values are determined by ROC curve analysis. Values are presented in counts/15 seconds. Sensitivity and specificity of the determined cut-point values in predicting the right activity class are also calculated. | First one-hour observation | 
| Sensitivity and specificity of the determined cut-off point values | Activity count cut-off points derived from the first one-hour observation are cross-validated by determining their sensitivity and specificity in predicting the right activity class during the second one-hour observation. | Second one-hour observation | 
| Intra- and inter-subject variation in time spent in different activity classes | Intra-subject variation in time (%) spent in different activity classes between different days and inter-subject variation in time spent in different activity classes are determined. | 7-day accelerometer measurement | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Motor activity, Infant, Validation studies, Malawi, Sub-Saharan Africa