Created by Paul Litwin, Collaborative Data Services, Fred Hutchinson Cancer Reseach Center, Seattle

A Microsoft .NET-based implementation of a set of REDCap Data Entry Triggers.

• Created with Visual Studio 2015.
• .NET version: 4.5.2.
• Built as an ASP.NET WebAPI web service using C# programing language.
• Uses Log4Net for logging.
• Includes unit test for Adaptive randomization code.
• Extensive comments in source code.

• See GitHub releases.

• DotNetDETs - This is the main project containing three WebAPI endpoints:
  • DETExample - a basic example of a .NET data entry trigger. Implemented using class DotNetDETs/Controllers/DETExampleController.cs.
  • Adaptive - a .NET data entry trigger that implements Adaptive Randomization in REDCap. Implemented using class DotNetDETs/Controllers/AdaptiveController.cs.
  • DatabasedNotify - a .NET data entry trigger that reacts to a saved survey and then, based on the value of a field on the survey, adds the record to the appropriate data access group and emails the appropriate site contact.
• DotNetDETUnitTests - This is a unit test project for testing the Adaptive Randomization code.

A description of each of the endpoints and supporting code follows...

This is basic example of a data entry trigger built in asp.net as a WebAPI web service. It uses common code (see below).

This REDCap DET implements Adaptive Randomization per Smoak and Lin http://www2.sas.com/proceedings/sugi26/p242-26.pdf. One difference from the Smoak and Lin paper is that there is no run-in of simple randomization as mentioned in the paper. Instead, only the first assignment for each covariate group is randomly assigned using simple randomization. Thereafter, all subjects in that group are randomized using adaptive randomization.

Here is the hook code used to create a Randomize Participant button on our randomization form which mimics the Save and Continue button on a REDCap form. It uses the Andy Martin REDCap Hook Framework. This PHP code shown here is not included in the source of this .NET project.

<?php
	// Saved to a file named redcap_data_entry_form.php and placed in the hooks folder for the appropriate project
	switch ($instrument) {

        case "randomization":
			print '<script type="text/javascript">$(function() {$("input[name=\'pc_rnd_ready\']").replaceWith("<input type=\'button\' id=\'btnRandomize\' name=\'submit-btn-savecontinue\' style=\'font-weight:bold;font-size:12px;margin:1px 0;\' onClick=\'dataEntrySubmit(this);return false;\' value=\'Randomize Participant\' />"); });</script>';
			break;

        default:
		//nothing to do
	
	}
?>

The DotNetDETUnitTests unit test project allows you to quickly randomize a bunch of subjects to see if the adaptive randomization routine is working properly.

Performs two actions based on the value of the cityField field:

1. Adds form to appropriate data access group (DAG) based on city.
2. Notifies appropriate contact at the site for that city.

Note: The DatabasedNotifyEmailsTestMode config setting of true diverts all emails to test recipient. Need to set to false when in production.

The common code under the Infrastructure folder consists of the following classes:

1. RedCapDETBModelBinder.cs is used to parse the posted values passed to the DET by REDCap.
2. RedCapAccess.cs contains routines to read and write records to REDCap. The REDCap API code was adapted from the work of Chris Nefcy.
3. Metadata.cs is a class used to store the metadata (data dictionary) from the ExportMetadata API call.
4. Messaging.cs is used to send asynchronous emails.