Physical Activity and Gastrointestinal Investigations
This is an observational study, which aims to compare the outcomes of ambulatory gastrointestinal investigations with physical activity using accelerometry. An ambulatory study refers to one in which the patient is monitored freely, often outside of the hospital environment. For this the investigators will use a lightweight (7.4g) tri-axial accelerometer worn behind the ear.
For capsule endoscopy, the investigators are interested in how physical activity affects the speed of capsule transit through the GI tract. Capsule endoscopy involves a patient swallowing a pill which contains a camera, in order to image the parts of the bowel that a conventional endoscope cannot reach. A rapid transit may result in insufficient mucosal visualisation, which would reduce the sensitivity of the investigation.
For oesophageal pH monitoring, it is essential that the patient behaves as they would normally to produce measurements that represent a standard day. Using accelerometry, the investigators can compare the amount, and nature, of physical activity taken throughout the investigation to that of the preceding day, or week. In addition, further analysis of motion data captured will allow us to correlate specific activities and body orientation with pH readings to get a better insight into the pathophysiology of a patient's condition.
The studies will be conducted over 6-9 months in Imperial College Trust's medical outpatient service. All patients undergoing capsule endoscopy or ambulatory oesophageal monitoring will be asked to consider participating. Patients will receive the eAR sensor up to 2 days before their investigation, and will be asked to wear it until the end of their investigation (not whilst sleeping). Capsule endoscopy normally takes less than 12 hours, and pH monitoring takes between 24 and 48 hours. Participation makes no difference to the standard or type of care that they will receive, the sensor data is additional.
Hypothesis 1 There is no change in the amount or nature of physical activity taken by patients during ambulatory oesophageal pH monitoring or capsule endoscopy.
Hypothesis 2 There is no correlation between physical activity levels and speed of gastrointestinal transit.
Gastro-oesophageal Reflux Disease
|Study Design:||Time Perspective: Prospective|
|Official Title:||An Observational Study to Compare the Outcomes of Ambulatory Gastrointestinal Investigations With Physical Activity Using Accelerometry.|
- Physical activity [ Time Frame: 5 Days per patient ] [ Designated as safety issue: No ]The primary outcome measure is amount of physical activity undertaken by participants throughout the study period. Participant motion data will be collected using a tri-axial accelerometer in the eAR sensor. Signal processing methods will be used to produce an activity index in the form of a numerical value, from the raw data.
- Subgroup analysis and vertical orientation [ Time Frame: 5 Days per patient ] [ Designated as safety issue: No ]Secondary outcome measurements will be produced through further processing of the raw data. This includes firstly breaking physical activity down into sub groups, i.e. low, moderate, and high intensity exercise undertaken. Secondly, we will produce a third outcome measurement by calculating the variation in vertical orientation of participants throughout the study period using two the constant influence of gravity on two of the axes of the accelerometer.
|Study Start Date:||March 2012|
|Estimated Primary Completion Date:||July 2013 (Final data collection date for primary outcome measure)|
|24 hour oesophageal pH study|
|Imperial College Healthcare NHS Trust|
|London, United Kingdom, W2 1NY|
|Principal Investigator:||Richard M Kwasnicki, BSc Hons||Imperial College London|