Field allergy trials typically overlap with high volume travel months, in particular, summer. Even small geographic shifts, such as movement between provinces or states, can result in a different exposures to seasonal allergens. Our electronic patient data acquisition tablet (ePDAT), has the ability to alert the system if the unit leaves a pre-defined, virtual perimeter (a geofence) in order to ensure subjects remain in an area known to contain the allergen of interest.
74 subjects consented to the study and utilized the ePDAT to monitor symptom scores during the grass pollen season. The ePDAT is equipped with internal GPS receiver which provides accurate geo-location device tracking in real time (in hours & minutes). Based on previous pollen data for the grass season, we determined an appropriate geofence to ensure subjects would remain exposed to grass pollen. The ePDAT sent an alert message if it left the pre-defined geofence area, as plotted on an interactive worldwide map.
The geofence system reported that 4 of 74 subjects (5%) left the pre-defined grass pollen area over the course of the study, for an average of 3 days. 95% of subjects remained within the defined area as required by the study.
ePDAT is very effective tool to determine subject compliance in a seasonal allergy field trial. Subjects who remain within the desired allergen region helps ensure more accurate study results.