FHIR's Observation Component List: Proper Usage and Misuse Examples

Details

Observation is one of the most commonly used resources in FHIR, designed to capture key/value pairs of various measurements (e.g., heart rate, body weight). For complex values composed of multiple parts, the Observation's component list must be utilized instead of the simpler 'value' element. However, this component list is often misused. A critical rule for correct usage is determining if any value within the list can be interpreted in isolation from the others. If multiple data points (e.g., weight and height) each have independent meaning and do not rely on or depend on one another, they should not be grouped together. An Observation should capture only one piece of data point—whether simple (like weight) or complex (like blood pressure). Therefore, if two or more pieces of independent data are being captured, separate Observation resources must be created to maintain data integrity and interoperability standards.