Published Online
on May 7, 2007

A more recent version of this article appeared on May 22, 2007

This Article Full Text (PDF) All Versions of this Article: 115/20/2652    most recent CIRCULATIONAHA.106.678904v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Bazzani, L. G. Articles by Marcin, J. P. Search for Related Content PubMed PubMed Citation Articles by Bazzani, L. G. Articles by Marcin, J. P. Pubmed/NCBI databases Medline Plus Health Information Congenital Heart Defects Heart Surgery Related Collections Health policy and outcome research Pediatric and congenital heart disease, including cardiovascular surgery

Submitted on December 5, 2006
Accepted on March 9, 2007

Case Volume and Mortality in Pediatric Cardiac Surgery Patients in California, 1998-2003

Lianna G. Bazzani PhD, MPH and James P. Marcin MD, MPH^*

From the University of Texas School of Public Health, Houston (L.G.B.), and Department of Pediatrics, University of California at Davis Children’s Hospital, Sacramento (J.P.M.).

^* To whom correspondence should be addressed. E-mail: jpmarcin{at}ucdavis.edu.

Background--Previous reports have found an inverse relationship between pediatric cardiac surgery case volume and in-hospital mortality. This association has been noted recently to be decreasing for coronary artery bypass grafting, possibly because of improved training programs, quality improvement activities, or other innovations to improve outcomes. It is unknown whether the volume-mortality association among pediatric cardiac surgery patients is decreasing similarly.

Methods and Results--We used data from the state of California’s patient discharge data set from the years 1998-2003 to replicate 4 previous research studies of pediatric cardiac surgery volume and mortality. The total number of pediatric surgeries varied from 12 801 to 13 971 depending on the selection criteria applied. Using this larger and more contemporary data set, we found a weaker and less consistent volume-mortality relationship than had been reported previously. We also developed a new model, which incorporated elements of the old models, and found a statistically significant relationship with higher volume and lower mortality (odds ratio=0.86 per 100-patient increase in annual volume; 95% CI, 0.81 to 0.92). Post hoc analyses show that this relationship was related to the performance of the single largest-volume hospital.

Conclusions--With the use of data from California, the volume-mortality relationship among pediatric cardiac surgery patients has changed since previous research, such that the old models no longer describe a clear or consistent association. With the use of a continuous definition of volume and an updated model, an association is observed but is dependent on highly leveraged covariate patterns found in the largest-volume hospital.

Key words: heart defects, congenital • hospitals • pediatrics • quality of health care • survival

This article has been cited by other articles:

				K. F. Welke, S. M. O'Brien, E. D. Peterson, R. M. Ungerleider, M. L. Jacobs, and J. P. Jacobs The complex relationship between pediatric cardiac surgical case volumes and mortality rates in a national clinical database. J. Thorac. Cardiovasc. Surg., May 1, 2009; 137(5): 1133 - 1140. [Abstract] [Full Text] [PDF]

				K. F. Welke, B. S. Diggs, T. Karamlou, and R. M. Ungerleider Comparison of Pediatric Cardiac Surgical Mortality Rates From National Administrative Data to Contemporary Clinical Standards Ann. Thorac. Surg., January 1, 2009; 87(1): 216 - 223. [Abstract] [Full Text] [PDF]

				K. F. Welke, B. S. Diggs, T. Karamlou, and R. M. Ungerleider The Relationship Between Hospital Surgical Case Volumes and Mortality Rates in Pediatric Cardiac Surgery: A National Sample, 1988-2005 Ann. Thorac. Surg., September 1, 2008; 86(3): 889 - 896. [Abstract] [Full Text] [PDF]

				S. L. Bratton Case Load and Mortality in Pediatric Cardiac Surgery AAP Grand Rounds, August 1, 2007; 18(2): 17 - 18. [Full Text] [PDF]

				K. Gauvreau Reevaluation of the Volume-Outcome Relationship for Pediatric Cardiac Surgery Circulation, May 22, 2007; 115(20): 2599 - 2601. [Full Text] [PDF]