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Measures stores the indicators of cost, quality and experience used to measure the numeric values found in the 'entity_values' table. It's primary key is the measure_id and the author_id is a foreign key which links the measure to the 'measure_authors' table.
Measures may be duplicated where there are two sources for the same measure data, or where measures have been versioned. In each case, a new measure ID is created. For examples SCIP measures are captured from national CMS data but also captured from local sources that are one quarter more current. The measures are exactly the same, but the collection process differs as does the reporting period, therefore a new measure is created.
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