Calibration and Cross-Validation of Accelerometry in CF
Research type
Research Study
Full title
Calibration and Cross-Validation of Accelerometry in youth and adults with Cystic Fibrosis
IRAS ID
220354
Contact name
Melitta McNarry
Contact email
Sponsor organisation
DRI
Duration of Study in the UK
2 years, 0 months, 3 days
Research summary
Summary of Research
Cystic Fibrosis (CF) is genetic condition that causes sticky mucus to accumulate in the lungs and elsewhere, leading to repeated lung infections and poor exercise tolerance. While physical activity is recognised as important in the treatment of people with CF, it’s unclear what the right amount of physical activity is to obtain health benefits. A key problem with developing appropriate recommendations for those with CF is that all of our techniques to measure people’s daily activity have been developed for healthy people and don’t take into account the higher resting energy costs or higher energy cost of any given activity in those with CF. This means children with CF may be more active at a higher intensity than we think because the wrong thresholds have been used. The purpose of this study is to develop disease-specific thresholds for identifying the intensity of activity in those with CF so we can more accurately assess how active they are and what needs to be done to promote activity in this population.
It is well known that physical fitness improves life expectancy in CF and that regular physical activity (PA) is directly related to quality of life. Additionally, structured PA has been shown to improve fitness, thoracic mobility, bone mineral density, and reduce the frequency of hospitalisations. However, despite the fundamental role that PA plays in a CF patient’s life, studies using objective measurement of physical activity have shown that only 2.1% of children with CF meet the recommended government guidelines of 60 minutes moderate-to-vigorous physical activity every day.
Accelerometry is a physical activity tracking device that provides an objective measurement of PA, and it has been widely used to assess children and adult’s PA levels under various conditions and health statuses. However, it was developed based on healthy populations and might provide a wrong amount and intensity of PA when used to track individuals with clinical conditions. The only way to track the right amount and intensity of PA in clinical populations is to perform a calibration of the accelerometer to that specific condition. Nonetheless, despite the importance of PA in the treatment of people with CF, currently only one study performed the calibration of accelerometry for this population.Summary of Results
This study helped to create a way to see how active young people with cystic fibrosis (CF) are. We measured how much energy young people with CF needed to complete some activities they would normally do in their daily lives and created a way to measure how active they were using algorithms and statistics. This study also helped us to demonstrate that normal ways that are commonly used to measure how active young people with CF are, were not useful or accurate. We also showed that when measuring how active young people with CF are, we need to consider if they are a boy or a girl and the day of the week. We then used a complex method called compositional data analysis to understand how being active affects the lungs of young people with CF and we found that being active can help to delay how CF affects the lungs. For example, we demonstrated that young people with CF had an improvement in their lungs when they reduced 30 minutes of being sedentary or doing a light-intensity activity to increase 30 minutes of doing moderate-intensity activity or sleep.
REC name
West of Scotland REC 5
REC reference
18/WS/0032
Date of REC Opinion
16 May 2018
REC opinion
Further Information Favourable Opinion