Major Findings: While there are low-volume hospitals that provide excellent care and high-volume hospitals that provide relatively poor care, numerous studies confirm that patients undergoing Coronary Artery Bypass Graft (CABG) surgery by a low volume HCP provider or at a low volume HCO provider have a significantly higher risk of mortality compared to patients undergoing CABG by a high volume HCP provider or at a high volume HCO provider. Patients undergoing high risk surgical procedures can significantly reduce their risk of post operative death by selecting a high-volume provider versus a low volume provider.

Methodology: PurpleLab examined Medicare Fee-For-Service administrative claims during subsequent periods 2010 to 2014 using CMS Limited Data Sets (LDS). PurpleLab identified CABG procedures using a number of relevant ICD9 procedure codes. Each CABG procedure observed within the period of study was identified as an “indexing event”. Using the date of the claim for the “indexing event”, queries were executed to scan for “peri-event” (within procedure data and discharge date (“DSCHRGDT”) as well as 90-day “post event” for mortality. PurpleLab examined patient status (“PTNTSTUS” = “B”) and discharge status fields (“STUS_CD” = 20, 40, 41, 42 in the LDS claims files as well as the death status fields (“DEATH_DT” and “V_DOD_SW”) in the denominator files within the “post event” period to identify pos-operative mortality. PurpleLab established rates for mortality that support the other published studies showing that lower volume HCPs and HCOs experience higher actual mortality rates.