title: The Association Between Treatment Frequency and Treatment Outcome for Cardiovascular Surgeries.
abstract: BACKGROUND
  This study analyzed the association between the volume of heart surgeries and treatment outcomes for hospitals in the last five years.
  
  
  METHODS
  Hospitals that perform heart surgeries were chosen throughout Korea as subjects using from the Health Insurance Review and Assessment Service. The treatment outcome of the heart surgeries was defined as the mortality within 30 postoperative days, while the annual volume of the surgeries was categorized. Logistic regression was used as the statistical analysis method, and the impacts of the variables on the heart surgery treatment outcomes were then analyzed.
  
  
  RESULTS
  The chance of death of patients who received surgery in a hospital that performed 50 or more surgeries annually was noticeably lower than patients receiving operations from hospitals that performed fewer than 50 surgeries annually, indicating that the chance of death decreases as the annual volume of heart surgeries in the hospital increases. In particular, the mortality rate in hospitals that performed more than 200 surgeries annually was less than half of that in hospitals that performed 49 or fewer surgeries annually.
  
  
  CONCLUSIONS
  These results indicate that accumulation of a certain level of heart surgery experience is critical in improving or maintaining the quality of heart surgeries. In order to improve the treatment outcomes of small hospitals, a support policy must be implemented that allows for cooperation with experienced professionals.
authors.affiliation: Health Insurance Review and Assessment Research Institute, Health Insurance Review and Assessment Service.
authors.forename: Ji Suk
authors.initials: JS
authors.lastname: Choi
authors.affiliation: Health Insurance Review and Assessment Research Institute, Health Insurance Review and Assessment Service.
authors.forename: Choon Seon
authors.initials: CS
authors.lastname: Park
authors.affiliation: Health Insurance Review and Assessment Research Institute, Health Insurance Review and Assessment Service.
authors.forename: Myunghwa
authors.initials: M
authors.lastname: Kim
authors.affiliation: Health Insurance Review and Assessment Research Institute, Health Insurance Review and Assessment Service.
authors.forename: Myo Jeong
authors.initials: MJ
authors.lastname: Kim
authors.affiliation: Department of Preventive Medicine, Konkuk University School of Medicine.
authors.forename: Kun Sei
authors.initials: KS
authors.lastname: Lee
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, The Catholic University of Korea College of Medicine.
authors.forename: Sung Bo
authors.initials: SB
authors.lastname: Sim
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Konkuk University Medical Center, Konkuk University School of Medicine.
authors.forename: Hyun Keun
authors.initials: HK
authors.lastname: Chee
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Keimyung University School of Medicine.
authors.forename: Nam Hee
authors.initials: NH
authors.lastname: Park
authors.affiliation: Thoracic and Cardiovascular Surgery, Kangwon National University Hospital.
authors.forename: Sung Min
authors.initials: SM
authors.lastname: Park
keywords: Quality of health care; Thoracic surgery; Volume-outcome relationship