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multiple_choice_questions_in_cdisc_odm

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Multiple Choice Questions in CDISC ODM

We regurarly get questions about “multiple choice” or “check all that apply” questions in CDISC ODM, i.e. questions that seemingly have a codelist, but for which it is allowed to check or select more than one answer.

Consider the question: “Did you suffer any of the following tropical diseases in the last five years? Please check all that apply”

  • Chagas disease
  • Dengue
  • Leishmaniasis
  • Malaria
  • Onchocerciasis (river blindness)
  • Schistosomiasis (snail fever)

The ODM specification does not tell us how to treat such questions. Obviously, we cannot use a CodeList, as there is also a rule that states that within an ItemGroupData, the same ItemOID may only occur once.

So, what can we do?

In such cases, it is always a good idea to take a step back and go back to the basics. What is a multiple-choice list?

So the following is not allowed:

<ItemGroupData ItemGroupOID="...">
  <ItemData ItemOID="**IT.TROPICAL_DISEASE**" Value="Malaria"/>
  <ItemData ItemOID="**IT.TROPICAL_DISEASE**" Value="Schistosomiasis"/>
</ItemGroupData>

Also using a list of comma-separated values is not a good idea, as the value itself may contain a comma. So the following is also not good:

<ItemGroupData ItemGroupOID="...">
  <ItemData ItemOID="IT.TROPICAL_DISEASE" Value="Malaria, Schistosomiasis"/>
</ItemGroupData>

Essentially, it is a list of items for which each can have the value “true” or “false”, e.g. “Yes” I did have malaria, and “No”, I did not have Dengue. So let us treat this as a list of items with boolean values! ODM does support the “boolean” data type as of v.1.3. So we could write the following in the “Study” part of the ODM:

<ItemDef OID="IT.CHAGAS" Name="Chagas disease" DataType="boolean"/>
<ItemDef OID="IT.DENGUE" Name="Dengue" DataType="boolean"/>
<ItemDef OID="IT.LEISHMANIASIS" Name="Leishmaniasis" DataType="boolean"/>
<ItemDef OID="IT.MALARIA" Name="Malaria" DataType="boolean"/>
<ItemDef OID="IT.ONCHORCIASIS" Name="Onchocerciasis (river blindness)" DataType="boolean"/>
<ItemDef OID="IT.SCHISTOSMIASIS" Name="Schistosomiasis (snail fever)" DataType="boolean"/>

Essentially, it is besser to explicitely have the question itself in the “Question” child element, especially when the study runs in several countries with different languages. For example:

<ItemDef OID="IT.SCHISTOSMIASIS" Name="Schistosomiasis (snail fever)" DataType="boolean">
  <Question>
    <TranslatedText xml:lang="en">Schistosomiasis (snail fever)</TranslatedText>
    <TranslatedText xml:lang="de">Schistosomiasis (Bilharziose)</TranslatedText>
</ItemData>
 
multiple_choice_questions_in_cdisc_odm.1389643607.txt.gz · Last modified: 2014/01/13 21:06 by manager