This class represents a test result or observation that may be reported. Some tests, such as an microbiology identification may have multiple results reported over time, for example a preliminary gram stain result might be initially reported, followed by the identification and relative number of organisms, followed by an antibiotic senstivity test results. Each one of these results would manifest as a separate instance of this class, each with their own date/times, performers, etc. "The OBX segment is used to transmit a single observation or observation fragment. It represents the smallest indivisible unit of a report." - HL7 Version 2.8, OBX