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 repetitively 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 phase.
Report type: repeated measure
Before a repeated measure field can be added to the study form, a report type called repeated measure should be created. For more information on creating a new report, refer to creating reports.
Creating a repeated measure field
Once you have created the repeated measure report, you can add a repeated measure field to the study.
To create a repeated measure field, go to the Form builder and navigate to the appropriate study phase and step and select the field type 'Repeated measure'. You can also add this field within another report. Define the properties of the field:
When creating a repeated measure field, you can choose to display measurements for all linked phases or reports for a specific repeated measure:
It is also possible to create calculations within repeated measure fields. For example, a score can be calculated as part of each measurement. However, it is not yet possible to calculate the number of measurements in a calculation field.
In data entry, the repeated measure field looks like this:
By selecting 'Add measurement', 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 report and will appear in the Reports tab. Each report will be attached to the phase (or report) where the repeated measures field is located.
Importing repeated measure data
First, export the repeated measure to Excel. Even where no data has been entered to the repeated measure, the exported spreadsheet will provide a template containing the columns that need to be completed and data can simply be added to the corresponding columns. The 'creation date' column should be left blank, as this is automatically created with the creation of the report. This is what a prepared spreadsheet for import should look like:
Be aware that, unlike the study import method, you cannot create new records while importing repeated measure data. The records must exist in Castor before the data can be imported.