This ValueSet is part of the Health Device Data Transfer specification (HDDT) which defines profiles, operations, and value sets for sharing data between medical aids and digital health applications (DiGA). Core of the HDDT specification are Mandatory Interoperable Values (MIVs). MIVs are classes of measurements that contribute to defined use cases and purposes of DiGA.

This ValueSet defines the Mandatory Interoperable Value (MIV) "Lung Function Testing". The definition is made up from

• this description which provides the semantics and defining characteristics of the MIV
• a set of LOINC codes that define MIV-compliant measurement classifications along the LOINC axes component, system, scale and method.

The MIV Lung Function Testing covers values from lung function testings that are performed by exhaling air into a hand-held peak flow meter or spirometer. Measurements are performed twice a day, or more frequently if required by the care plan or the patient's condition.

The ValueSet for the MIV Lung Function Testing includes LOINC codes for measuring the Peak Expiratory Flow (PEF) and Forced Expiratory Volume in 1 second (FEV1). Also included are LOINC codes for the corresponding reference values, and relative values (e.g. FEV1 measured/predicted). This ValueSet does not include LOIC codes directly, instead the codes come from three separate ValueSets:

• HddtLungFunctionTestingValues: codes for individual lung function testings
• HddtLungFunctionReferenceValues: codes for lung function reference values
• HddtLungFunctionRelativeValues: codes for relative lung function values, calculated in percentages (%)