Successful linking of the Society of Thoracic Surgeons adult cardiac surgery database to Centers for Medicare and Medicaid Services Medicare data.

Background: The Centers for Medicare and Medicaid Services (CMS) Medicare database complements The Society of Thoracic Surgeons (STS) database by providing information about long-term outcomes and cost. This study demonstrates the feasibility of linking STS data to CMS data and examines the penetration, completeness, and representativeness of the STS database.

Methods: Using variables common to both STS and CMS databases, STS operations were linked to CMS data for all CMS coronary artery bypass graft surgery (CABG) hospitalizations discharged between 2000 and 2007, inclusive. For each CMS CABG hospitalization, it was determined whether a matching STS record existed.

Results: Center-level penetration (number of CMS sites with at least one matched STS participant divided by the total number of CMS CABG sites) increased from 45% to 78%. In 2007, 854 of 1,101 CMS CABG sites (78%) were linked to an STS site. Patient-level penetration (number of CMS CABG hospitalizations done at STS sites divided by the total number of CMS CABG hospitalizations) increased from 51% to 84%. In 2007, 94,409 of 111,967 CMS CABG hospitalizations (84%) were at an STS site. Completeness of case inclusion at STS sites (number of CMS CABG cases at STS sites linked to STS records divided by the total number of CMS CABG cases at STS sites) increased from 88% to 97%. In 2007, 88,857 of 91,363 CMS CABG hospitalizations at STS sites (97%) were linked to an STS record.

Conclusions: The successful linking of STS and CMS databases demonstrates high and increasing penetration and completeness of the STS database. Linking STS and CMS data will facilitate studying long-term outcomes of cardiothoracic surgery.