2c389a02__Specifications___openEHR_wiki__openEHR_equivalent
[0] 3 [Code mnemonic] NASK [Rubric] not asked [Description] This information has not been sought (e.g., patient was not asked) [openEHR equivalent] 
Q: is this a missing data concept, when by definition no data is expected to be there? In any case can only apply in specific questionnaire-like situations. Should be part of design of archetypes / templates for questionnaires. My response is the same as above; the patient wasn't asked. When does this make a difference? Probably not to a system, but maybe to a user. But why should I have to worry about this for every item in a template? generically, I may not ask, or the patient may refuse to answer, any question. Let's just build that into the infrastructure; it seems to me that these are reasonable things to have in openEHR nullFlavor, even though they may not be widely used.
Null Flavours and Boolean data in openEHR - Specifications - openEHR wiki
openEHR equivalent