What is JTrack?¶
A COLLABORATIVE TOOL FOR PASSIVE MONITORING AND ECOLOGICAL MOMENTARY ASSESSMENTS
Scope of application¶
The JTrack platform consists of the two JTrack applications EMA and social and a server structure to enable central data collection. The platform was developed to gather study specific digital phenotyping information about smartphone usage, sensor data and participants’ (“users”) self-perceptions of specific events or activities that occur in their daily lives. The JTrack platform was developed as an open source collaboration tool to enable clinical and behavioral researchers to collect their own digital phenotyping data from specific study populations.
The JTrack social application was developed to collect sensor data from sensors embedded in any modern smartwatches and smartphones aside with general smartphone usage information. Thereby, the specific sensor and phone usage measure combinations are study specific and completely customizable. Thereby, a high priority is assigned to data privacy to ensure that the collected data do not contain any identifiable or personal information. In example, the GPS information is encoded into a random coordinate system to ensure that the location of the user cannot be derived from the data. The JTrack social has two different modes which can be used selectively or combined. The first is passive monitoring not requiring any interaction with the user and second is active labeling, where the user enters a specific activity she or he currently performs and the sensor data are labeled using this provided information. The JTrack EMA application was developed to collect questionnaire data in longitudinal studies. Using the JTrack EMA application, one can user-generated” data, which are based on users’ interactions or responses to fully customizable surveys in the application. These data are collected, transferred, and saved in our servers anonymously. In addition, both apps can collect “derivative data”. These are collected automatically for technical reasons such as sending push notifications, error logs, and providing smooth application behaviour. This information will not be stored and contains no user identifiers. Both apps only collect data from users who have registered for a study and have accepted the necessary permissions that are provided during installation. By installing the applications without participating in our studies, we will not collect, store, or have access to any “user-generated” data. For all participants of each study only the study specific information is collected as specified in the written informed consent.
Sensor Data¶
The following is a non-exhaustive list of data that can be collected using the JTrack social platform in a customizable manner:
2.1 Location data¶
A relative GPS location is recorded providing relative position of the phone to an anonymized reference place. This phone tracking will allow estimating the amount of mobility (i.e. distance covered per day) and the number of unique locations participants visit during that time. Anonymization: all location information will be anonymized by using a random relative reference point including rotation and will at no time allow identification of actual position of the phone.
2.2 Smartphone usage¶
The number, time stamps and duration of phone calls can be recorded aside with the number of outgoing and incoming messages. This information will provide an estimate of phone usage for social communication. Anonymization: no information will be recorded with respect to any sensitive information such as the phone number of the participant or the recipient or the content of the respective calls and messages.
2.3 Activity recognition¶
The time and duration of the following activities can be collected using automated activity recognition: in vehicle, on bicycle, running, walking, still, phone tilting. This information will be used to evaluate the general activity types and durations of the participants. Anonymization: all activity recognition will be performed on the phone and only the information about time and the type of the recognized activities associated with the anonymized device ID will be collected.
2.4 App usage¶
Timing, duration and the name of the used apps can be collected to allow evaluation of social versus non-social smartphone usage (i.e. gaming, social communication, internet surfing). Anonymization: only the app names and the time stamps of using the respective apps will be collected but never the content of the respective interactions.
2.5 Accelerometer and gyroscope¶
Accelerometer and gyroscope data can be recorded to estimate movement patterns of the participants. Anonymization: the sensor information is only combined with anonymized JTrack specific study and subject ID.
Ecological Momentary Assessments¶
The information collected in each specific study are outlined in the respective written informed consent and the study protocol. Such information may include:
3.1 Personal data¶
If required for study conduct, personal information (such as your name and email address and clinical information) may be collected during studies. These data are not stored via the application but only in study- specific dedicated databases. These data are only accessible to people who are directly involved in study conduct. This information will never be used to identify your other personal information or to contact you for other reasons than study conduct.
3.2 Demographic and clinical data¶
Demographic and clinical data may be collected for relevant questions if specified in the respective study protocol and written informed consent. Such data are not collected via the application but only in study-specific dedicated databases that are only accessible to people who are directly involved in study conduct or subsequent data analyses.
3.3 User-generated survey data¶
The information users may provide when entering and responding to surveys. This data is not saved alongside their personal data. All survey results are confidential and will not be used to identify any personal data.
3.4 Derivative data¶
The information our application automatically collects when users access the EMA application, such as application version, information of device operating system or log files. This information is saved or preserved and will be deleted once the application is uninstalled. None of our employees has direct access to this material. And these data cannot be linked to identify any person, including you.
Device Access Permission¶
We may request access or permission to certain features from users’ mobile device. these requests are necessary to provide you with a smooth experience of application usage as well as to get access to study specific sensors. We provided a list of all the request users that may be required by the application, i.e.
Camera access: we used camera access to scan provided Qr-Codes which are used to activate the application.
GPS information: the information is required for location tracking. The coordinates are anonymized on the phone as described above prior to transfer to the central JTrack server.
File read and write access: we used file read and write access to write and save information about the survey (i.e. images).
Battery optimization: to prevent the application from sleeping we ask the user to disable battery optimization.
Users may alter their access or permissions at any time by going through the device’s settings.
4.1 Push Notifications¶
If required for study conduct, we may request to send users push notifications. These notifications are in the form of online (which will be sent by our servers) or offline (which will be generated by the application) notifications. Online notifications are used to send further information from our servers to the users while offline notification provides information on newly available questions or the operation status of the application.
Data Usage¶
5.1 Intended use of collected information¶
We may use the information collected from users via the JTrack applications to:
Conduct data analysis for internal use and publication (scientific journals and conferences) as per study specific protocols
Share anonymized data with other researchers (if covered by the specific study protocols and informed consents)
Improve the efficiency and operation of the applications.
Resolve troubleshoot issues.
5.2 Third-party data sharing¶
The users’ personal information will be never exchanged with a third-party application/ organization. If covered by study protocol and informed consent the information collected in a study may be shared in an anonymized manner with other researchers.
5.3 Disclosure of information¶
Your personal information is never shared with others who are not directly involved in the study conduct. Your personal information will never be used for reaching out to you for any other reasons than study conduct. The information you provided during the study will never be used or shared for marketing, advertisement, or other non-scientific purposes. We may share the anonymized information that we have obtained in a study to address specific scientific questions or if required to verify integrity of the published study outcomes.
Data Security¶
To help secure users’ information, we use administrative, technological, and physical security measures. All information obtained via the application is sent over a protected channel using the Hypertext Transfer Protocol Secure (HTTPS) protocol. Further checking (e.g., MD5 checksum) also applied to avoid any mismatches and interruption during the data transfer process. We used a random number generator to produce all of the unique identifier information, such as the user and device IDs. Any personally identifiable information is only collected via dedicated and study specific mediums. This information is never linked, stored or shared together with user-generated data from the application. All the employees who have access to this information are obligated in writing to maintain data security.
For Study Participants¶
Users may at any time stop data collection or leave the study directly within the application. In case of the loss of a device, users may request the study owners to stop data collection. If data collection is performed in a non-anonymized manner and a participant decides to leave the study they may request study owners to terminate their account and to delete the already collected data. This option is yet only possible if the information is not collected in an anonymized manner and was not yet used for a scientific publication in which case the study owners are legally obliged to store all publication relevant data for a duration of 10 years after study conduct (if not specified otherwise in the study protocol).
Data Access¶
Access to the information collected via the JTrack applications is only provided to qualified employees/researchers with direct involvement in study conduct or data evaluation. Access to personal information is only provided to researchers who are directly involved in data collection. All the employees who have access to this information are obligated in writing to maintain data security and comply with the regulations specified in this document. All employees who have access to the information collected in a study will never try to de-identify any user participating in the respective studies and will never contact you for any other purpose than specified in the study protocol.