Chapter 3. Defining Data Fields

Global Settings

Global study specifications have an impact on field definitions and thus need to be considered before defining fields.

Import CRFs

The CRF plates on which the data fields are defined need to be brought into DFsetup. Alternatively, if data is collected via EDC then eCRF plates can also be added using Study > Add eCRF Plate.

Import Definitions

When possible, importing style, module and field definitions from other studies, or a special CRF library database, saves a lot of work. All you require is view permission for the source study setup.

Plates

A label and other properties need to be specified for each imported plate.

Styles

Every data field needs a style.

Modules

All fields must be defined within a module before mapping them to a plate.

Select Fields To Be Copied

Fields in the current selection set are shown using the foreground color. A field is selected by clicking it with the mouse. Other fields can be added to create a selection set by holding down the shift key while clicking each field.

A group of fields can also be selected by holding the shift key down and then clicking and holding the left mousebutton while dragging a box around the desired fields.

You can also select all the fields in a module by clicking the module label or selecting the module from the Plates-Modules-Fields list.

There is no method for removing a single field from the current selection. Instead you must cancel the entire selection set and start over. To cancel the current selection click anywhere in the background (while not holding the Shift key).

Copy the Selected Fields

Select Field > Copy to copy the current selection to the DFsetup clipboard.

Paste the Copied Fields

Select Field > Paste to create the new fields. The dialog shown below appears first.

The names and descriptions of the copied fields can be modified for the new fields by: pre-pending, appending or substituting specified strings. This is optional, and does not change the values in the clipboard copy.

To make the same change to all three field properties, check the box beside the first row. This propagates changes made to this row to the other 2 rows.

Click OK to paste the new data fields onto the page or Cancel to abort the paste operation.

Position the New Fields

The pasted data fields appear offset just below the copied fields and must be moved into position on the page. This is done by clicking and holding the left mousebutton over any one of the pasted fields and then dragging the entire set of fields into position.

To end the paste operation, leaving the pasted fields in their current position, left-click anywhere in the CRF window background. Individual fields can then be selected and dragged if necessary to adjust their final position.

Edit the New Fields

After creating the new fields you may need to edit some of the field properties to finish their definition. This is done by selecting each field and editing in the Field Properties panel.

Enter DFsetup in Exclusive Access Mode

No other user can be in the study database while these changes are being made.

Import the Revised CRFs

Import the revised CRF pages as described in Import CRFs. Because the plate number on a revised CRF already exists in the study setup, the import dialog will show Replace beside the plate number. This indicates that the new CRF page will replace the existing one. You do not need to import all CRF pages, only the ones to be modified.

Adjust Field Positions

Any fields which no longer appear in the correct locations should be selected and moved to their new positions on the CRF. When doing this be sure you do not change the field numbers. If you need to change the field traversal order this can be done by applying edit checks as described below.

Deleting Fields or Modules

Do not delete data fields or modules if you want to be able to retrieve this data in the future or you want to be able to create an audit trail tracing the history of these fields using Field > Show History of All Changes to This Field in DFexplore. When a field or module is deleted from the study setup, DFdiscover permanently deletes any values that exist for these fields, and the fields themselves, when the setup changes are saved. Also it is important to realize that you cannot re-create deleted fields in the setup to bring them back, because each new field gets a new internal field tracking number, even if the field is given the same name and appears on the same plate. A re-created field has no link to any previously deleted version of that field.

Instead of deleting fields you no longer want to appear in DFexplore we recommend that you hide them, either by setting the Hidden field property to 'Yes' so that users without permission for hidden fields do not see them, or by using edit check function dfaccess.

If you decide to delete fields or modules, and then use report DF_ATmods to produce an audit trail showing the history of all changes on the plate that contained these fields, the report shows the history of the deleted fields and the point at which they were deleted. This is true even if you also delete the plate itself.

Adding Fields or Modules

When a new field is created, it is automatically assigned the next field number after the last one on the plate and thus does not change the numbering of existing fields. The new field must already be defined in a new or existing module.

If you do not want the new fields to be positioned at the end of the plate drag them to the desired location on the CRF page, but leave the field numbers unchanged. We will fix field traversal in the next step.

When fields are added to the end of a plate DFdiscover will reformat the existing data records to insert the new fields with blank values. Thus the data records will change but the field order will not change for all of the data collected so far.

Changing Field Traversal Order

By default DFexplore traverses data fields in field number order when a user tabs through the data fields on the plate. If you have reordered fields or positioned new fields between existing fields, this is no longer the desired field traversal order. An edit check can be used to achieve the desired order, without changing field numbers, as illustrated below.

# Run: on field exit
# Use: change backward and forward fields traversal
# Arg: f1 = next field on backward traversal
#      f2 = next field on forward traversal
edit GOTO(number f1, number f2)
{
       if( dfdirection()>0 ) dfmoveto(@[f2]);
  else if( dfdirection()<0 ) dfmoveto(@[f1]);
}

For example, if a new field numbered 44 has been positioned between fields 15 and 16 use edit check GOTO as follows:

A similar approach can be used to skip over "deleted" fields (which are not really deleted, just no longer relevant). For example field 22 could be skipped by adding GOTO(21,23) as a field entry edit check on field 22. This has no effect if the user clicks on field 22 with the mouse but is skipped when keyboarding through the fields.

Test The Revised Plate

First review the revised plate in the DFexplore List view to verify that any new fields appear at the end of the data records, as expected. Then build a task set containing the revised plates using Select > By Data Fields in the DFexplore Data view, and tab through the fields to check: field traversal order, edit check behavior, and data field values.

Other Revisions

Although this procedure does not change the numbering of existing data fields you may need to make revisions to include any new fields you have added in: edit checks, DFsas jobs, shell scripts, and task and list view definitions. Any required modifications are much less complicated than would have been the case had you changed field numbering on the plate.

Deleting Plates

A plate can be deleted from the study setup by selecting Study > Delete Plate, and then removing the plate from the study Visit Map using View > Visit Map. Deleting a plate deletes the plate definition from the study setup and makes it impossible to enter new data records or retrieve existing data records for the deleted plate.

Deleting a plate has no effect on other plates.

Important

Do not delete a plate (or data field) and then re-create it. Each new data field gets a new internal field tracking number, thus any such re-created fields would be considered new with no link to the deleted fields, even if you define them with the same field name on the same plate number. When the setup is saved DFdiscover deletes the data values for all deleted fields. It thus becomes impossible to retrieve them. Also since the study setup no longer includes the definition of deleted fields it is not possible to generate an audit trail report that focuses just on the deleted fields. To show the history of deleted fields DF_ATmods must be run to show all changes on the relevant plate.

Hiding a Plate

Instead of deleting a plate you may simply want to hide it from some or all users. A plate can be hidden from selected users by changing the role definitions set for all DFexplore users in DFadmin.

Simply removing a plate from the study visit map, while making it impossible to enter new data records for that plate, does not prevent users from retrieving and changing existing data records, unless the records are hidden using dfneed in the DFopen_patient_binder edit check. If this is not done the existing data records are shown as unexpected (by the current study visit map) in the subject binder.

Adding New Plates

Since each plate is stored in a separate data file a new plate can be added at any time with no impact on existing plates. The process is the same as the steps followed to create the original study plates. PDF files containing the new CRF images are imported, and given new plate numbers. New styles, modules and data fields can then be created as needed for the new plates. As soon as the new plates are added to the study visit map, they become available in DFexplore for data entry. This can be done while users are logged in to DFexplore but such users do not see the new plates unless they exit and re-enter the study, or the next time they login.

Adding New Versions of Existing Plates

Sometimes the revisions required to an existing CRF plate are so extensive that it is not possible to simply modify the existing plate as described in Modifying Plates that Contain Data. Instead a new version of the CRF page with a new plate number may be required. As described above adding a new plate can be done at any time, but how do we tell DFdiscover that this new plate is a new version of an existing plate?

To accomplish this we need to make some changes to the study visit map and add some new cases to the conditional visit map. First, if the old version of the plate was required at some visits the visit map must be changed to make the new version required and move the old version to the optional plate list. And if the old version was optional the new version needs to be added to the optional list so that both versions appear in the optional list.

The final step is to add two new conditions to the conditional visit map, one that declares the new version unexpected if the old version has been entered, and another which declares the old version unexpected if the new version has been entered.

Modify the CRF page to add the new choice box options and save it as a PDF file.

Open the module view and select the module and field you wish to modify. Add the new choice option to the field properties and save it.

Import the revised CRF page using Study > Import CRFs to replace the existing CRF background image. This has no effect on the data fields already defined on this plate.

Adjust the position of data fields on the new CRF background, as needed by dragging them to their new locations on the page.

Drag the widget for the choice field to be changed out of the way, and then click each of the boxes making up the field, just as though you were defining it all over again.

When all choice boxes have been identified, click the choice field widget that you moved out of the way. A dialog appears asking if you want to relocate the data field to the new boxes you have just checked.

Click Yes. The data entry widget you moved out of the way vanishes and the revised field definition moves to the new data entry widget you just created.