Relationship between processes of care and coronary bypass operative mortality and morbidity.
BACKGROUND
Information is limited regarding the effects of processes of care on cardiac surgical outcomes. Correspondingly, many recommended cardiac surgical processes of care are derived from animal experiments or clinical judgment. This report from the VA Cooperative Study in Health Services, "Processes, Structures, and Outcomes of Cardiac Surgery," focuses on the relationships between 3 process groups (preoperative evaluation, intraoperative care, and supervision by senior physicians) and a composite outcome, perioperative mortality and morbidity.


METHODS
Data on 734 risk, process, and structure variables were collected prospectively on 3,988 patients who underwent coronary artery bypass grafting at 14 VA medical centers between 1992 and 1996. Data reduction was accomplished by examining data completeness and variation across sites and surgeon, using previously published data and clinical judgment. We then applied multivariable logistic regression to the 39 remaining processes of care to determine which were related to the composite outcome after adjusting for 17 patient-related risk factors and controlling for intraoperative complications.


RESULTS
Our first analysis showed several measures of operative duration, the use of inotropic agents, transesophageal echo, lowest systemic temperature, and hemoconcentration/ultrafiltration, to be powerful predictors of the composite outcome. Because the use of inotropic agents and operative duration may be related to an intermediate outcome (eg, intraoperative complications), we performed a second analysis omitting these processes. The use of intraoperative transesophageal echo and hemoconcentration/ultrafiltration remained significantly associated with an increased risk of an event (odds ratios 1.60 and 1.36, respectively).


CONCLUSIONS
Our results viewed in the context of past studies suggest the possibility that inotropic use, TEE, and hemoconcentration/ultrafiltration may have adverse effects on operative outcome. Further evaluation of these processes of care using observational data, as well as randomized trials when feasible, would be of interest.
O'Brien
Maureen M
MM
Medical Research Service, Denver VA Medical Center, Denver, CO 80220, USA.
Shroyer
A Laurie W
AL
Moritz
Thomas E
TE
London
Martin J
MJ
Grunwald
Gary K
GK
Villanueva
Catherine B
CB
Thottapurathu
Lizy G
LG
MaWhinney
Samantha
S
Marshall
Guillermo
G
McCarthy
Martin
M
Henderson
William G
WG
Sethi
Gulshan K
GK
Grover
Frederick L
FL
Hammermeister
Karl E
KE
D001026:Coronary Artery Bypass / Q000379:methods* / Q000401:mortality* / Q000706:statistics & numerical data; D006302:Health Services Research; D017052:Hospital Mortality; D006787:Hospitals, Veterans / Q000592:standards*; D006801:Humans; D007430:Intraoperative Care / Q000379:methods / Q000592:standards; D009017:Morbidity; D015999:Multivariate Analysis; D016017:Odds Ratio; D010043:Outcome and Process Assessment, Health Care / Q000458:organization & administration*; D011300:Preoperative Care / Q000379:methods / Q000592:standards; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D014493:United States Department of Veterans Affairs