This value sets refers to 3 different sources of observation method codes, each with issues:

• SNOMED CT Techniques (descendents of 272394005): As for August 2015, this is relatively complete (e.g. includes all LOINC methods). However this includes more than just observation methods, and is subject to the normal SNOMED CT licensing rules
• v3 Code System "ObservationMethod": this is very incomplete and not currently maintained

This value set includes content from SNOMED CT, which is copyright © 2002+ International Health Terminology Standards Development Organisation (IHTSDO), and distributed by agreement between IHTSDO and HL7. Implementer use of SNOMED CT is not covered by this agreement.