Explanation of DCD specifications

The above Data Collection Definition (DCD) specifications are published in an MS Excel file using a slightly modified XLSForm format. XLSForm is a form standard created to simplify the creation of forms. The creation is done in a human readable format. XLSForms are a convenient standard for sharing and collaborating on form creation. For a detailed guide to the XLSForm standard, we refer you to https://xlsform.org/en/.

Each DCD Excel workbook has three worksheets: "settings", "survey" and "choices". Sometimes a project is composed of several DCDs. In this case, a "survey" worksheet is created for each DCD. The lists of values for all DCDs are listed in a single "choice" worksheet.

While not all survey and choice characteristics are used by healthdata.be to describe the data collection definitions, all standard XLSForm columns are present in the MS Excel file.

Note: healthdata.be itself does not use the XLSForm standard to create its DCD in its own applications (HD4DP, HD4Patient). The XLSForm standard (used by popular electronic data capture systems such as OpenClinica, LibreClinica, ODK,…) is chosen to describe the DCD only because it is a human readable format.

The "Survey" worksheet

This worksheet gives the general structure of the DCD and contains most of the content. It contains the complete list of variables and information on how they should appear in the form. Each row usually represents one variable.

The following columns are primarily used in the survey worksheet to describe DCD:

• type: Defines the type of question/variable
• name: Unique ID (name) of the question / variable
• label::[English]: Question / variable in English, appears on the screen
• label::[French]: Question / variable in French, appears on the screen
• label::[Dutch]: Question / variable in Dutch, appears on the screen
• label::[German]: Question / variable in German, appears on the screen
• hint::[English]: Hint or explanatory text for a question, in English
• hint::[French]: Hint or explanatory text for a question, in French
• hint::[Dutch]: Hint or explanatory text for a question, in Dutch
• hint::[German]: Hint or explanatory text for a question, in German
• constraint_javascript: Constraint on the allowed values for a response defined in javascript
• constraint_message::[English]: The message displayed to the user if the answer is not valid, in English
• constraint_message::[French]: The message displayed to the user if the answer is not valid, in French
• constraint_message::[Dutch]: The message displayed to the user if the answer is not valid, in Dutch
• constraint_message::[German]: The message displayed to the user if the answer is not valid, in German
• required: If a question or variable must be completed for the form to continue or be submitted
• relevant_javascript: Skip logic condition (the relevant condition that must be met for this question to be displayed)
• read_only: If a variable question/answer can be changed
• calculation
• repeat_count: Number of repetitions for a group of repetitions
• hidden: Hidden fields in the HD4DP application

The "Choices" worksheet

This worksheet is used to specify answer choices for multiple choice questions. Each row represents an answer choice. Answer choices with the same list name are considered part of a set of related choices and appear together for a question/variable. This also allows a choice set to be reused for multiple questions/variables (for example, yes/no questions).

The following columns are primarily used in the choices worksheet to describe the DCD:

• list_name: A unique name for each choice set
• name: ID (name or code) of the specific choice
• label::[English]: The choice label, in English, appears on the screen
• label::[French]: The choice label, in French, appears on the screen
• label::[Dutch]: The choice label, in Dutch, appears on the screen
• label::[German]: The choice label, in German, appears on the screen

 

The "Settings" worksheet

• form_title: Title displayed at beginning of form, in form list
• public_key: Key required for encrypted forms
• submission_url: Specific URL for uploading data
• default_language: If form uses multiple languages, this one sets which to use by default
• style: Separate questions groups into pages. Switch to a different theme.
• instance_name: Allows user to create a dynamic naming convention for each submitted instance
• status: status of the form: options are "final" and "draft"
• start_date: date start form in production
• end_date: date end form in production