Longitudinal projects provide collection of data over time in order to track changes and progress. Longitudinal projects are useful in the following situations:
Long Term Studies
Clinical Trials
Recruitment & Enrollment Combinations
Multi-Site Studies
Repeating Surveys It is extremely important to give much consideration to the design, development and testing of your Longitudinal Project. Understanding reporting considerations & needs is critical. Thorough testing is essential for success.
INITIAL CONSIDERATIONS
Enabling longitudinal feature allows any form or survey to be reused over the course of time and provides opportunity to designate specific instruments at specific time points (events). Longitudinal instruments eliminate the need to recreate the same form for multiple time points. Instead, the form is created once and then assigned to various time points throughout the project. Examples of forms used in longitudinal mode include:
Medications
Lab results
Adverse events forms
NOTE: You must EXPAND the below section(s) to view the full content. Click the (>) carrot to expand.
These are the basic steps involved in setting up a Longitudinal Project. A step by step process is described in-depth below.
2. Enable Longitudinal Functionality
Enable Longitudinal Mode at the project level
Navigate to your project
Select the "Project Setup" tab
Click the "Enable" button next to 'Use Longitudinal data collection with defined events"
3. Set up User Rights, Roles, &/or DAG’s
Assigning User Rights to team members should be a carefully thought out decision. The consequences of poor user rights decisions could be damaging to the security and integrity of the project. See Knowledge Article User Rights & Roles
The User Rights page can be used to determine the roles that a user can assume within a REDCap database. The Data Access Group on the other hand determines the data visibility of a user within a REDCap database. A typical use of Data Access Groups is a multi-site study where users at each site should only be able to view data from their site but not any other sites. Users at each site are assigned to a group, and will only be able to see records created by users within their group. See Knowledge Article Data Access Groups
4. Define Events (and/or) Arms
Define Events / Arms for the Project (e.g., patient visits, tasks or point in time)
On Project Setup Page, navigate to "Define My Events"
Type the title of the event in the text box then click Add New Event
Repeat above steps until each of your events have been created
5. Designate Instruments to Events
Link Instruments to relevant events
From the Project Setup page, navigate to "Designate Instruments for My Events"
Select "Begin Editing" button
Click to place a checkbox on the grid for each instrument / form / survey that should be assigned to each specific event
Click "Save"
In order to ensure that other advanced features like reporting and data quality checks in REDCap work properly, always assign the first form to the first event. (i.e. Order your instruments appropriately)
You can link and un-link events in your project during your project set-up and test. Once the project is in Production linking /unlinking events must be done by REDCap Administrator. Reason: You can lose data if you unlink an event.
6. Test, Test & Test
a. It is strongly recommended that you test your projects prior to moving to Production to ensure the project works as desired and reports are presented in the desired format with complete data.
b. Use test data as close to real as possible and simulate the workflow you intend to use.
c. Knowledge Article – Testing Your Project
7. Setup Schedules (Optional feature- not required)
a. While setting up scheduling is options, it can only be used with Longitudinal projects, expand the below section to review Scheduling setup & functionality
Longitudinal Calendar (optional feature) You can not link to Google / Outlook Calendars of the department) . However, it does allow a REDCap user to view the calendar, and open any patients scheduled for that day and open the instruments for that event.
Can turn on / off as desired (prod or development)
Can't limit user rights. Have access to calendar and all its features
Produces automatically generated schedules
by participant
based on how set up Arms and Events
Calendar event status can flag "no show" or "cancel" for visit status
To enable, on Project Setup page navigate to Enable Optional Modules section and click on Enable next to Scheduling module
Click on Scheduling on left navigation bar.
Select a patient (or create new), define start date & ARM, click Generate Schedule
Can input times and switch scheduled days of the week by changing dates if desired
When done modifying the Projected Schedule, click Create Schedule
You will see a notice that your calendar was successfully created
j. To see the Calendar, navigate to left Navigation pane and select Calendar under Applications
k. Here you see the time and event for Participant 3
l. From the calendar, you can click on the event and see:
a. Data entry forms for the participant
b. Study ID, event , status
c. Can add notes as desired
Advanced Longitudinal Study
Two Arms and 3 Events are shown here, but you can have as many Arms & Events as you want / need for your study
Each Arm is its own silo where a record goes
Records should only be in one Arm.
NO record transfer between arms
Can assign forms to various Events and Arms as needed
Arm names can be created & assigned by user. Arm numbers assigned by REDCap
No direct user restriction. If you give user access to a form which is in multiple arms they will be able to see multiple arms
To separate by sites, need to use Data Access Groups or create separate projects
Set up project as described above.
Additional Arms are added on the Define Events Page
Events
Defined by
Event Name (e.g., Baseline, Event 1)
Can be assigned by user
Unique Event Name Assigned by REDcap
Assigned by REDCap based on event name and arm #
Based off event name and arm number (Baseline_Arm_1)
Important in branching logic and auto invitations
Note the Event Name (User defined) & the Unique Event Name (generated by REDCap) for Arm
Note the Event Name (User defined) & the Unique Event Name (generated by REDCap) for Arm 2
Repeating Events
Only works for Longitudinal Model
Repeat any event as many times as needs
Used for situation where the # of needed events differs per record (e.g. Chemotherapy cycles)
Limitations
Makes analysis more challenging
Can not add a repeating instrument to a repeating event
Assign instruments to each event. Do this for each Arm as described above
Data Entry
Navigate to Add/Edit Records on Left Navigation Bar
Select Arm Record is to be assign to and create new record or select from dropdown
Select Target Form in the desired Event
Enter Data or open/send survey.
Longitudinal Exports
Multiple Rows for Participants
Exports a row for each Event in each Arm
Lots of blank spaces
Best to use a Statistical Export over Excel to eliminate blank spaces
Additional Considerations
Best practice to always add Record ID to every arm to prevent REDCap issues, especially if using surveys
Create a "single landing page" with just Record ID. Can be invisible to user with a "Thanks for Participating Page" with Submit to continue. See Knowledge Article Longitudinal Surveys
Actions that can cause data loss in Longitudinal Projects:
Deleting Events
Deleting Arms
Decoupling Forms from Events
If you create additional forms once project is in Production, need to request REDCap support to link forms to Events.
Give much consideration to User Rights. If you want to segregate data based on location but have a form that is common to both sites, a user with rights to that form will see data from both sites. Create Data Access Groups
Branching logic in a Longitudinal Project must identify the arm and the field name.
Classical Branching Equation:
[field1] = '3'
Longitudinal Branching Equation:
Can cross both forms and events, so need to indicate event and field
[event_3][field1] = '3'
Survey Expiration
Is server time, not what is on your computer
Survey expiration takes all copies of the survey offline.
Warning: If you have survey that is used multiple times in a longitudinal survey if you expire the survey after the first event, be aware that it will expire all the surveys in following events
Save and return later
The User Code is often lost and user can't find the code when they want to return to complete the survey.
Alternative is to design shorter surveys and poll multiple times via automatic invites
Deleting or Disabling a survey in Survey Settings.
There are 2 "delete" buttons for any given project.
1 is in Online Designer – deletes entire form and data is lost
1 is in Survey Settings – reverts survey back to a form. Data is still available
When defining Events it is important to think about the days offset and use an accurate representation in case you ever want to use scheduling