Time Representation in Fox DEN
Temporal Variables in Fox DEN
CSV (comma separated value) files downloaded from Fox DEN contain complementary columns that provide the ages of Fox Insight participants along with information that can be used to determine when events occurred over time. Event dates have been explicitly excluded to protect patient confidentiality.
The age of the Fox Insight participant when the event occurred. Ages are rounded to one decimal place for patient confidentiality.
The number of days that have elapsed since "Day 0" — a reference date unique to each Fox Insight participant that is defined a few months after the participant's birth date. Use this column to determine the number of days between events.
Note: Starting with the February 2022 data cut, the days_elapsed variable in the “Registration” survey was changed to reflect the time from Day 0 to the day each participant registered for Fox Insight. This provides a chronological starting point for the days_elapsed variables in other surveys which are defined using the last day each participant responded to the survey.
The number of days the Fox Insight participant took to complete a survey (often participants were not required to finish surveys during one visit). When this column is present, each CSV row contains information from the same acquisition period.
The number of 30 day periods after the participant registered with Fox Insight. This number aligns with the Fox Insight Schedule of Activities.
Survey Responses (Through )
The graphic representation below depicts how often participants answered each survey (logarithmic scale). Many surveys were administered at different frequencies over different time periods; see details below for more information.
Survey Version Details
Prior to September 5th 2019, participants had 90 days to complete study visit questionnaires. This created the potential for an extremely short buffer period between subsequent study visits (e.g., a participant could complete a survey on day 89, and then complete the survey again on day 91). This window has been shortened to 30 days, allowing for a 60-day buffer period between study visits.
Not all participants took the same surveys with the same cadences. In the example illustration below, version 1 of the survey was administered 3 and 12 months after registration, but version 2 was administered 6 and 15 months afterwards. This resulted in cumulative survey responses different from the cadences of either version. The Fox Insight Schedule of Activities lists the current cadence of each survey.