Setting Minimum and Maximum Dates (Bounds) for Event Variables

Modified on Mon, 15 Apr 2024 at 06:00 PM

What are Event Bounds?

Event Bounds allow users to set minimum and maximum limits for the dates of Event variables in their Electronic Case Report Forms (eCRFs). Unlike Numeric variables, which have static bounds, Event variables can have both static bounds (fixed dates) and dynamic bounds (patient-specific dates). Dynamic bounds depend on the value of another Event variable, offering unparalleled flexibility and control over data entry.

The use of Event Bounds is aimed at:

- Enhancing the quality control over data during entry, ensuring that the dates fall within the specified range.

- Decreasing the time needed for data monitoring by automatically validating the dates as they are entered.


Event Bounds are available for:

- Users with "Manage variables" permission.

- All series and all custom Event variables.

- Note: Identity Event variables do not have programmable bounds yet

Implementing Event Bounds

Setting Bounds

  1. Activation: A new checkbox titled “Minimum and maximum bounds” is now present for every Event variable. By default, this box is unchecked for both new and existing variables.
  2. Configuration: Upon checking the box, new input fields appear, allowing the definition of minimum and maximum dates. Unchecking the box will hide these inputs.
  3. Date Selection: Users can choose the min/max dates using a Vue variable picker that displays options in this order: a specific date (e.g., today’s date), “Today”, any Identity Event variables, and all other custom Event variables except the currently edited one.
  4. Specific Dates: For “A specific date” option, a date picker enables users to select any present or future date without restrictions.
  5. Variable-Based Dates: Choosing an Identity Event variable, a custom Event variable, or the “Today” option allows users to optionally define a time range around the selected date by adding a ± period.

Example of Dynamic Bounds

For a 3-month visit event, you could set:

- A minimum (AFTER) bound as Inclusion date + 85 days.

- A maximum (BEFORE) bound as Inclusion date + 95 days.

Error Handling

- While entering data for a patient, if an entry falls outside the set bounds, it won’t be saved, aligning with the error handling for numeric variables.

- Error messages guide users on the correct entry based on the bounds set.

Special Considerations

- Patient-specific bounds require the associated date to be known. If the related date is not specified, the system allows the entry without bounds validation.

- ePRO Support: Just like numeric variables, questionnaires must support the defined bounds for Event variables.

- API and Duplication: The API reflects similar error handling for out-of-bound entries, and when duplicating categories, the bounds of Event variables are not duplicated.

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