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| Code mnemonic | Rubric | Description | openEHR equivalent |
1 | NI | no information | The value is exceptional (missing, incomplete, improper). No information as to the reason for being an exceptional value is provided. This is the most general exceptional value. It is also the default exceptional value. | (same in openEHR) |
2 | INV | invalid | The value as represented in the instance is not an element in the constrained value domain of a variable. | - |
3 | OTH | other | The actual value is not an element in the constrained value domain of a variable. (e.g., concept not provided by required code system). | Q: This seems to be saying that a value has been recorded in violation of the model? |
4 | NINF | negative infinity | Negative infinity of numbers. | Modelled in Interval<T> and DV_INTERVAL<T> classes (. |
4 | PINF | positive infinity | Positive infinity of numbers. | Modelled in Interval<T> and DV_INTERVAL<T> classes (. |
3 | UNC | unencoded | No attempt has been made to encode the information correctly but the raw source information is represented (usually in originalText). | In openEHR, original data from external systems appears in FEEDER_AUDIT.original_content (UML). |
3 | DER | derived | An actual value may exist, but it must be derived from the provided information (usually an expression is provided directly). | This can happen anywhere in the data; openEHR doesn't see it as missing data / null data. The archetype shows what is derived and what is not, e.g. Apgar total from input values. |
2 | UNK | unknown | A proper value is applicable, but not known. | (same in openEHR) |
3 | ASKU | asked but unknown | Information was sought but not found (e.g., patient was asked but didn't know) | In openEHR, this is a legitimate response of the patient, and is not a case of missing data. See discussion above. |
4 | NAV | temporarily unavailable | Information is not available at this time but it is expected that it will be available later. | Q: What information systems can predict te future and reliably set a value like this? What use would it serve? If the data are in fact available later, they will be recorded. |
3 | QS | sufficient quantity | The specific quantity is not known, but is known to be non-zero and is not specified because it makes up the bulk of the material.'Add 10mg of ingredient X, 50mg of ingredient Y, and sufficient quantity of water to 100mL.' The null flavor would be used to express the quantity of water. | In openEHR, this is not missing data. It just happens to be quantitative data that is expressed in narrative form. Modelled in archetypes by allowing a narrative alternative to a quantity. |
3 | NASK | not asked | This information has not been sought (e.g., patient was not asked) | 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. |
3 | TRC | trace | The content is greater than zero, but too small to be quantified. | This is a laboratory concept, and has nothing to do with missing data; labs routinely specify some amounts as 'trace'.The value not in itself computable, but is usually part of an ordered set, e.g. trace, +, ++ etc. |
2 | MSK | masked | There is information on this item available but it has not been provided by the sender due to security, privacy or other reasons. There may be an alternate mechanism for gaining access to this information.Note: using this null flavor does provide information that may be a breach of confidentiality, even though no detail data is provided. Its primary purpose is for those circumstances where it is necessary to inform the receiver that the information does exist without providing any detail. | (same in openEHR) |
2 | NA | not applicable | No proper value is applicable in this context (e.g., last menstrual period for a male). | (same in openEHR) |
This is the HL7 nullFlavor table as of Dec 2007. (Grahame)
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