Placeholder ID
From DOC
A placeholder is automatically identified by an internal number which is unique among all placeholders (of any type) within the database. However, this identifier is insufficient for external purposes:
- The id is not globally unique, two Tolven databases will assign the same series of numbers.
- Identifiers created by other systems cannot be used as the unique internal id.
In Tolven, a PlaceholderID refers to an external identifier. The general format follows the HL7 II (Instance Identifier) datatype. Example of external identifiers:
- Social Security Number
- Medical Record Number
- Placer Number
- Filler Number
- National Provider ID
- DEA License Number
A Tolven placeholder ID is made unique as follows:
- Account - Each account contains a separate placeholder ID namespace. For example, say a patient uses one Social Security number at one clinic and another Social Security number at a different (unrelated) clinic. The clinics in this case would have no way to know which social security number, if any, is the correct one.
- Placeholder type - identifiers are never mixed between placeholder types. For example, a patient placeholder and a physician placeholder may have a social security number but these identifiers are not intermixed.
- IDRoot - This is typically a unique OID that identifies an assigning authority such as the U.S. Social Security Administration.
- IDExtension - This is is a unique identifier within the domain specified by IDRoot.
Caution should be used used when determining IDRoot. For example, it may be tempting to attribute an identifier directly to the U.S. Social Security Administration. However, that organization may have played no part in validating the IDExtension (social security number) for a patient. In many cases, the SSN may simply be a number reported by the patient to the provider. In this case, it may be more appropriate for the provider to use an IDRoot that is created by the provider that, in effect implies no more than the truth: "SSN as reported to this organization" with no assumption that the patient would provide the same number to another provider or that the number is even valid. Now, when a SSN is used as an insurance identifier, it is much more likely to be validated. In that case, the IDRoot refers to that insurance carrier specifically, and not U.S. Social Security Administration in general. So, if the patient has two insurance carriers, then there should probably be two different IDRoots, even if the IDExtensions happen to contain exactly the same value.
Tolven and HL7 also define an Assigning Authority Name attribute in an instance identifier (placeholder Id). This attribute is optional and not used for matching.
