The Implementation Guide for the International Patient Summary based on HL7’s Clinical Document Architecture (CDA) 
was the one of the first artifacts developed by a collaboration of standards development organizations (SDOs).
The work for this first Implementation Guide (IG) for the IPS was mainly started at a meeting in Paris, France, in March 2017 (see picture). The group with around 20 experts and an extraordinary strong involvement of HL7 affiliates created the IG – based on the Clinical Document Architecture (CDA) Release 2 – using templates and suitable value sets and prepared a first official HL7 ballot later in 2017.
Initially, a few structuring choices have been made, considering that CDA is just the first but not the only one planned “technical data format” for the IPS. The group, experienced with many years of CDA specification and implementation, defined a set of – partially new – rules for the use of CDA to optimally support the intended scope of this IG. The use of vocabulary with SNOMED CT as the reference terminology, dealing with absent information and with multilingual aspects were just a few of the design principles for the IPS Implementation Guide. Tooling for collaboration and the creation and maintenance of templates and value sets as well as the domain model was also an important factor.
Finally, the IPS focus use case “cross-border care” was not seen as the only expected usage scenario for the IPS. Some European countries already had manifested their interest on the IPS work for their future national Patient Summary for unscheduled care at that time.
With HL7’s Clinical Document Architecture IPS Implementation Guide, patient summary initiatives around the world started to implement it and brought in feedback for the IPS community. Please note that the published standard can be found here , the build site for the IG can be seen here.