Relationship between preventability of death after coronary artery bypass graft surgery and all-cause risk-adjusted mortality rates.
BACKGROUND
The goal of this study was to determine the relationship between all-cause, risk-adjusted, in-hospital mortality after coronary artery bypass graft surgery and the proportion of preventable in-hospital deaths as a measure of quality of care at an institution level.


RESULTS
We conducted a retrospective analysis of 347 randomly selected in-hospital deaths after isolated coronary artery bypass graft surgery at 9 institutions in Ontario over the period of 1998 to 2003. Nurse-abstracted chart summaries were reviewed by 2 experienced cardiac surgeons who were blinded to patient, surgeon, and hospital and used a standardized implicit tool to identify preventable death. A third reviewer reassessed all cases in which the first 2 reviewers disagreed. Rates of preventable deaths were estimated for each hospital and compared with all-cause mortality rates. A structured adverse event audit completed by each surgeon-reviewer was used to identify quality improvement opportunities for the preventable deaths. A total of 111 of 347 deaths (32%) were judged preventable despite a low risk-adjusted mortality range (1.3% to 3.1%) across hospitals. No significant correlation was found between all-cause, risk-adjusted in-hospital mortality rates and the proportion of preventable deaths at the hospital level (Spearman coefficient, -0.42; P=0.26). A large proportion of preventable deaths were related to problems in the operating room (86%) and intensive care unit (61%). Many deaths were associated with deviations in perioperative care (32% based on concurrence of 2 reviewers, and another 42% in cases in which 1 reviewer reached that opinion).


CONCLUSIONS
Approximately one third of in-hospital coronary artery bypass graft deaths were judged preventable by surgeon reviewers. All-cause risk-adjusted mortality rates are convenient measures of institutional quality of care but were not correlated with preventable mortality in our jurisdiction. Providers should conduct detailed adverse event audits to drive meaningful improvements in quality.
Institute for Clinical Evaluative Sciences, G-106, 2075 Bayview Ave, Toronto, Ontario M4N 3M5 Canada. veena.guru@utoronto.ca
Veena
V
Guru
Jack V
JV
Tu
Edward
E
Etchells
Geoffrey M
GM
Anderson
C David
CD
Naylor
Richard J
RJ
Novick
Christopher M
CM
Feindel
Fraser D
FD
Rubens
Kevin
K
Teoh
Avdesh
A
Mathur
Andrew
A
Hamilton
Daniel
D
Bonneau
Charles
C
Cutrara
Peter C
PC
Austin
Stephen E
SE
Fremes
D000328:Adult; D001026:Coronary Artery Bypass / Q000009:adverse effects / Q000401:mortality* / Q000592:standards*; D003324:Coronary Artery Disease / Q000401:mortality* / Q000601:surgery*; D017052:Hospital Mortality; D006801:Humans; D016015:Logistic Models; D008485:Medical Audit; D009864:Ontario / Q000453:epidemiology; D016134:Organizational Policy; D011787:Quality of Health Care; D012189:Retrospective Studies; D012307:Risk Factors