Fig. 3From: A numerical similarity approach for using retired Current Procedural Terminology (CPT) codes for electronic phenotyping in the Scalable Collaborative Infrastructure for a Learning Health System (SCILHS)The top 4 CPT codes present at one or more of our seven sites but not in our augmented hierarchy. These account for 93 % of all missing instances across all sites. Most of the instances after 2004 are due to some sites using a different formulation of tetanus vaccine than Partners. This is also the only code used at multiple sitesBack to article page