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Should I use a Grid or a Repeated measure in EDC/CDMS?

Grid fields:

The Grid fields are used to group closely related data and display it as a table in an eCRF. A grid can contain as many rows and columns as you like. The fields can be set as text, number, dropdown, or date fields.

Here is an example of a grid field as seen in the study forms:

It is not possible to add a validation to each field, to make it as a required field or adjust the column or row size. That means that, if you have too many rows or columns, the users will need to scroll left/right and up/down to be able to fill in the whole grid. 

 

After the data has been collected in a grid field, it is not possible to change the number of rows or columns, nor the selected field types. In this case, it is advised to consider using the Repeated Measure field instead.

 

Use the grid fields if:

  • It is known in advance how many measurements (rows) should be added.
  • You need to add text, number, dropdown, or date fields.
  • It is not necessary to perform data validation on each field in a grid field.
  • If you would like to track changes in the audit trail per entire grid, not individual fields.
  • If you have a limited amount of datapoints that need to be collected in a grid, as large grid fields may cause performance issues.
  • You would like to collect data in a table format in a survey. Here is an example of a grid field as seen in a survey:

 

Repeated measure:

The repeated measure field is used to register repetitive events that can be measured from 0 to N times. 

The measurements will be shown in the form of a table, representing each measurement as a new row and each field that is part of the repeated measure as a separate column. It is possible to add any number of variables to a repeated measurement. 

 

Only 5 variables will be displayed in a form, plus a date column ‘Created on’ which represents a date when the measurement was added. Here is an example of a ‘Repeated measure field’ used for registering repetitive medications:

Since it is possible to add as many measurements as necessary, the ‘Repeated measure’ field should be used to collect repetitive data such as blood pressure, medication history, lab measurements etc. 

Each measurement will be created in the form of a new report and will appear in the Repeating Data Overview

 

Use the repeated measure fields if:

  • You would like to collect repetitive data in study or report forms.
  • It is not known in advance how many measurements (rows) should be added
  • The measurements may vary per participant (subject).
  • You would like to use different field types (not only text field, number, date and dropdown).
  • Data validation needs to be performed on each field.
  • If you anticipate any changes in the study forms and would like to add new variables at a later stage.
  • If you would like to track changes in the audit trail per field.
  • If you want the results in a separate CSV file with only the results of the repeated measure.
  • If you anticipate to collect a large number of repeating data.

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