The position of the body when the observation was done, e.g. standing, sitting. To be used only when the body position in not precoordinated in the observation code.

The qualitative change in the value relative to the previous measurement. Usually only recorded if the change is clinically significant.

A code representing the focus of an observation when the focus is not the patient of record. In other words, the focus of the observation is different from Observation.subject. An example use case would be using the Observation resource to capture whether the mother is trained to change her child's tracheostomy tube. In this example, the child is the patient of record and the mother is focal subject referenced using this extension. Other example focal subjects include spouses, related persons, feti, or donors.

A specific offset time in milliseconds from the stated time in the Observation.appliesDateTime to allow for representation of sequential recording of sampled data from the same lead or data stream. For example, an ECG recorder may record sequentially 3 leads four time to receive 12-lead ECG, see ISO 22077 .

This observation follows the target observation (e.g. timed tests such as Glucose Tolerance Test).

This observation replaces a previous observation (i.e. a revised value).

The Provenance/AuditEvent resources can represent the same information. Note that the Provenance/AuditEvent resources can represent the same information.

A code representing the the type of specimen used for this observation. Should only be used if not implicit in the code found in Observation.code.

Other preceding or concurrent observations that must be known to correctly interpret the the observation. For example an fiO2 measure taken alongside of a SpO2 measurement. See the Observation notes section for additional guidance.

Reference to reagents used to generate this observation. This is intended for this for in-lab transactions between instruments and Laboratory Information Systems (LIS).

Secondary findings are genetic test results that provide information about variants in a gene unrelated to the primary purpose for the testing, most often discovered when Whole Exome Sequencing (WES) or Whole Genome Sequencing (WGS) is performed. This extension should be used to denote when a genetic finding is being shared as a secondary finding, and ideally refer to a corresponding guideline or policy statement.

For more detail, please see: https://ghr.nlm.nih.gov/primer/testing/secondaryfindings.