Repeated measurements are a small set of related data points that semantically belong together and that are measured from 0 to N times. A good example is repetitive measurement of blood pressure, which can consist of several related data points that are always measured/registered together.
For example, you could use a repeated measure field if you want to repeatedly register the following elements:
- Blood pressure (systolic and diastolic)
- Position of the patient during measurement
- Date and time of measurement
Even though it is called a 'measurement', the repeated measure field can also be used for registering repetitive events that are not necessarily 'measurements'. For example, if you want to repetitively register medications during your study, the repeated measure field can be used to register the medications during each visit.
The repeated measurement fields allow to display data in a table in the study forms:
Report type: repeated measure
Before a repeated measure field can be added to the study form, a repeating data form type called Repeated measure should be created. For more information on creating a new repeating data form, refer to: Create a Repeating Data Form in CDMS
Creating a repeated measure field
Once you have created the repeated measure form, you can add a repeated measure field to the study.
To create a repeated measure field:
- Go to Study Design
- Go to the Forms page
- In the Form builder and navigate to the appropriate study visit and form, and select the field type 'Repeated measure'.
- Define the properties of the field
- Label: This is the name or question that will be displayed to the user entering data. For example, you might name it "Blood Pressure Measurements" or "Concomitant Medications".
- Repeated measure: This is a dropdown menu where you must select which Repeating Data form to link to this field which should already exist.
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Show all instances of this repeated measurement?: This setting controls what data appears in the grid for the user.
- If checked (Yes): The repeated measure table will act as a cumulative log. It will display all instances of this repeated measure that have been created for the participant across the entire study, regardless of which visit they were added in.
- If unchecked (No): The repeated measure table will only display the specific measurements that were added while the user was actively on this exact visit.
- Variables displayed in data entry: This dropdown allows you to select only the most important fields (variables) to display as columns in the repeated measure table. (e.g., You might only select the "Date" and "Systolic BP" variables to show in the grid, even though clicking into the measurement reveals more fields). Certain complex or structural field types cannot be displayed as columns in a Repeated Measure grid. You cannot select: Add Repeating Data Button, Add Survey Button, Link fields, Image fields, QR code fields,
- Button label: This allows you to customize the text on the button that the user clicks to add a new row. Instead of the generic default, you can change it to something specific like "Add Blood Pressure", "Log Dose", or "Add New Medication".
You can build calculations within individual repeated-measure fields (for example, calculating a score for each row). However, the system does not currently support calculating the total count of measurements inside a calculation field: Can I use calculations in repeating data in EDC/CDMS?
In data entry, the empty repeated measure field looks like this:
By selecting Add measurement (or the label of your choice), measurements can be easily added within the form and will be shown in the form of a grid, representing each measurement as a new row and each field that is part of the repeated measure as a separate column.
Each measurement will be created in the form of a new repeating data instance and will appear in the Repeating data tab. Each repeating data form will be attached to the visit (or repeating data form itself) where the repeated measures field is located.
Importing repeated measure data
To import data into your repeated measure fields, follow these steps:
Get the Template: Export your repeated measure form to Excel. Even if no data has been entered yet, this export serves as a perfect template by providing the exact column headers you need.
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Prepare the File: Add your data to the corresponding columns.
Important: Leave the creation date column blank. The system will automatically generate this timestamp when the data is imported. Make sure each repeated measure has a custom name
Run the Import: Follow the step-by-step guide in Import repeating data to upload your file.