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multiple_choice_questions_in_cdisc_odm [2014/01/13 21:21]
manager
multiple_choice_questions_in_cdisc_odm [2014/01/13 21:40] (current)
manager
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 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. 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: So the following is not allowed:
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   </​ItemGroupData>​   </​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, 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? 
 +   
 +Essentially,​ it is a list of items for which each can have the value "​true"​ or "​false",​ e.g. "YesI did have malaria", and "No, I did not have Dengue".
 So let us treat this as a list of items with boolean values! 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:  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: 
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   </​ItemGroupDef>​   </​ItemGroupDef>​
   ​   ​
-Now, as you have see I have set "​Mandatory"​ to "​Yes"​ in each case. This ensures that in the ClinicalData,​ there MUST be an ItemData for each of the six items, each containing a value of "​true"​ or "​false"​. The best way to implement this in a form would be to have two checkboxes after each question with the choices "​Yes"​ and "​No"​. Like that, I am sure that the subject did not forget an item, i.e. really thought about it whether he/she has suffered of the specific disease in the last first years.  +Now, as you have see I have set "​Mandatory"​ to "​Yes"​ in each case. This ensures that in the ClinicalData,​ there MUST be an ItemData for each of the six items, each containing a value of "​true"​ or "​false"​. The best way to implement this in a form would be to have two checkboxes after each question with the choices "​Yes"​ and "​No"​. Like that, I am sure that the subject did not forget an item, i.e. really thought about it whether he/she has suffered ​or not of the specific disease in the last first years.  
-If I had set the "​Mandatory"​ to "​No",​ there does not have to be an "​ItemData"​ for each question, but I could then implement it as having only one checkbox after each disease item, which is checked when the patient has suffered from the disease.+If I had set the "​Mandatory"​ to "​No",​ there does not have to be an "​ItemData"​ for each question, but I could then implement it as having only one checkbox after each disease item, which is checked when the patient has suffered from the disease. The disadvantage of that is that I will never know whether the subject really did not suffer of Dengue, or that the subject forget to answer the question.
  
-Personally, I prefer the former, as it is clearer and ensures that the subject really looked at each of the items. I.e. the data quality will be better.+Personally, I prefer the former, as it is clearer and ensures that the subject really looked at each of the items. I.e. the data quality will be better. Of course, it is more work for the subject to fill in the form.
  
-Now, you will say "where is the overal question 'Did you suffer any of the following tropical diseases in the last five years?'"?​+Now, you will say "where is the overal question '//Did you suffer any of the following tropical diseases in the last five years//?'"?​
  
 Well, that can be described in the "​Description"​ element of "​ItemGroupDef"​. For example: Well, that can be described in the "​Description"​ element of "​ItemGroupDef"​. For example:
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     <​Description>​     <​Description>​
       <​TranslatedText xml:​lang="​en">​Did you suffer any of the following tropical diseases in the last five years?</​TranslatedText>​       <​TranslatedText xml:​lang="​en">​Did you suffer any of the following tropical diseases in the last five years?</​TranslatedText>​
-      <​TranslatedText xml:​lang="​de">​Haben Sie sich an eine der folgenden Krankheiten erkrankt in den fünf letzten Jahren?</​TranslatedText>​+      <​TranslatedText xml:​lang="​de">​Haben Sie sich an eine der folgenden Krankheiten erkrankt in den letzten ​fünf Jahren?</​TranslatedText>​
     </​Description>​     </​Description>​
     <ItemRef ItemOID="​IT.CHAGAS"​ Mandatory="​Yes"/>​     <ItemRef ItemOID="​IT.CHAGAS"​ Mandatory="​Yes"/>​
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   </​ItemGroupDef>​   </​ItemGroupDef>​
  
-   +Maybe you will now say "OK Jozef, but you have overstretched the interpretation of the ODM specification a bit", and I must admit that this may be true.  
 + 
 +However, I think this is currently the cleanest way of implementing multiple choice or "check all that apply" questions using the current version of the ODM. It is in my opinion also an implementation that is easily mappable to the CDISC SDTM, e.g. using our popular [[http://​www.xml4pharma.com/​SDTM-ETL|SDTM-ETL]] software.  
 +In SDTM-ETL, you just drag-and-drop the whole ItemGroup to the SDTM cell (probably MHTERM in this case), and in the following wizard, check the box "​Generalize for all Items in the ItemGroup"​. 
 + 
 +Of course, for a next version of the ODM, the team will look into this again, and maybe come with an even better solution. One of the things were are thinking about anyway is about "​nested"​ ItemGroups, i.e. "​ItemGroups within ItemGroups"​. 
multiple_choice_questions_in_cdisc_odm.1389644492.txt.gz · Last modified: 2014/01/13 21:21 by manager