Managing category options

A category question contains a set of options which are presented to the data entry user. Each category option consists of a unique code and a descriptive value. These are managed in the Values tab of the question definition window.

Naming category codes and values

The category code is the unique identifier for the option. The category value is the descriptive text for the option.

Codes

Category codes must be unique within the question (but you can use the same category code in a different question).

A category code can be the same as its value, but it must not be the same as any other category value for the question. When answering a category question that displays as a drop down list, the data entry user can type the code or value into the question field. The response is checked firstly against the code and secondly against the value. So if the question contains a value that matches the code of another item and the user enters the value, the code of the other item will be selected instead.

We advise against using category codes with leading zeroes (e.g. 01, 02) as Arezzo expressions may not work as expected when referring to these code values.

When creating the category options male and female, we recommend that you use the standard codes which are 1 for female and 2 for male.

When writing Arezzo expressions which refer to category questions, you must always use the category code to refer to the question options, for example a condition which is true for female subjects would be gender=1

If you use a category question in a derivation the value will be the category code. If you want the value to be the text you can write a case statement. More help on derivation...

Values

The category value is free text. When the category question is displayed as option buttons only the category values are shown. When the question is displayed as a drop down list, you have the option of displaying just the values or both the values and the codes. This is set in the Display Code & Value field within the eForm definition window.

A category value can be the same as its code, but it must not be the same as any other category code.

Hiding category options

When you add a new option, a cross is displayed in the Active column to indicate that the category option will be displayed to the data entry user. If you want to hide a category value, click the cross to remove it.

This is useful if a value is no longer appropriate within a study, because once subjects have been recruited onto a study, you cannot delete category values.

You can also use dynamic sorting to specify when an active option should be displayed.

Sharing category options

You may want to use the same list in several places throughout a study. To achieve this, you can set one category question to share the options of another category question. Whenever the options are changed in the master question, they are automatically updated in all the reference questions too. They cannot be changed in the reference questions themselves and appear as read-only in the Values tab, in the same order as in the master question.

A 'master' question is a normal category question that is being referenced by another. You can see a list of all the questions that are referencing a master question within its question definition window.

You can use dynamic sorting to specify which options in a shared category question are displayed to the data entry user, and in which order. This means that users are not forced to view every option in the original order of the master list. For example, you may want to see a different subset of drugs from the same master list depending on the gender of the subject, and in each case, you would want the most common drugs at the top. See dynamic sorting

You can convert a reference question to a standard category question by removing the share. When removing a share, you can choose to keep or remove the options. If you keep the options, they will no longer be linked to the master question and so will not receive any future updates. They can be edited as a normal standalone list.

If you import a category question into your current study from another study in which the question shared the options of another question, it will be imported into the current study with no options.

Ordering category options

There are three ways to control the order in which a set of category options are displayed to the data entry user: manual sorting, alphabetic sorting and dynamic sorting.

Manual sorting

In the Values tab of the question definition window, click in the grey area to the left of an option and when the cursor changes to a hand holding a set of papers, you can drag the option up or down and drop it in the desired position.

Alternatively, you can enter a single positive integer into the Display Expression box. This integer determines the position in the list, with 1 being top or first in the list.

Alphabetic sorting

This enables you to sort the options alphabetically by code or descriptive value.

In the Values tab of the question definition window, use the 'Category Code Sorting' drop down list at the top right to choose one of the following alphabetic ordering types:

It is advisable to only use this drop down after you have finished entering options as when you add a new option or change the order by dragging and dropping, the sort order will revert to 'No Sorting'.

Dynamic sorting

In the Values tab of the question definition window, the Display Expression field enables you to enter an Arezzo expression for each option to define its order and visibility based on other data values. For example, you might want to only show a list of doctors relevant to a particular treatment, and you might want to order them according to which doctors work at which site. So if a subject at site London has liver disease, only doctors who treat that disease will be shown, and the doctors who work at London will be displayed first.

In this example, we have a category question containing a list of doctors. We want this list to be customised for each subject in two ways:

We only want to see doctors who treat the disease that the subject has
We want the doctor who works at the subject's site to be displayed at the top of the list

We will add a display expression to each doctor in the list, referencing another question 'subjectdisease' which has the values:

The display expressions look like this:

This means that Dr Abbott will only be displayed in the list if the answer to the 'subjectdisease' question is 2 (liver). In addition, if the site is London, then Dr Abbott will be listed in position 1. If the site is not London, Dr Abbott will be listed in position 10.

Dr Smith has no display expression and so will always be listed, but positioned below all doctors who do have a display expression.

Editing and deleting category options

You can only edit or delete an existing category option if the study has a status of In Preparation. So once a study status is set to Open, category values can be added, re-ordered and made Active or Inactive, but they cannot be changed or deleted. Note that you can still edit or delete a new value that has been added in the current SD session (since logging in).

No Sorting	Options will be displayed in the order that they have appear in the Values tab.
Sort on Code (ASC)	Options will be sorted by code in ascending order (0123456789ABC...)
Sort on Code (DESC)	Options will be sorted by code in descending order (ZYXWV...)
Sort on Description (ASC)	Options will be sorted by description in ascending order (0123456789ABC...)
Sort on Description (DESC)	Options will be sorted by description in descending order (ZYXWV...)