Het volume van chirurgische ingrepen en de impact ervan op ... - KCE

KCE Reports 113 Volume Outcome 151
RELATION BETWEEN SURGEON VOLUME AND MORTALITY RATE
Table 6.22 shows how the results from logistic regression confirm the effect of surgeon
volume on the risk of death, but to a smaller extent than hospital volume.
Table 6.22: CABG and/or heart valve replacement/repair: Results of logistic
regression: relative effect of 10% increase volume on mortality, surgeon
volume
Model without adjustment for case mix Effect 1 95% CI
Surgeon volume (increase of 10%) -2.34 -3.97 -0.71
Model with adjustment for case mix Effect 1 95% CI
Surgeon volume (increase of 10%) -1.89 -3.64 -0.15
OR 95% CI
Sex (male vs female) 0.77 0.62 0.95
Age (increase of 1 year) 1.06 1.05 1.08
Charlson score (increase of 1 category) 2.62 2.34 2.94
396 (Diseases of mitral and aortic valves) vs other 0.47 0.25 0.90
410 (Acute myocardial infarction) vs other 1.26 0.73 2.20
414 (Other forms of chronic ischemic heart disease) vs other 0.45 0.27 0.77
424 (Other diseases of endocardium) vs other 0.36 0.23 0.56
428 (Heart failure) vs other 0.61 0.29 1.28
441 (Aortic aneurysm and dissection) vs other 1.49 0.68 3.25
996 (Complications peculiar to certain specified procedures) vs 1.10 0.52 2.32
other
CABG + heart valve vs heart valve only 1.32 1.00 1.73
CABG only vs heart valve only 0.48 0.33 0.70
1 Effect of 10% increase in volume on the odds of mortality
6.2.7 Discussion
Analyses which take into account both surgeon as hospital volume concomitantly show
that hospital volume plays a more important role than surgeon volume. See Table 6.23.
Table 6.23: CABG and/or heart valve replacement/repair: Results of logistic
regression: relative effect of 10% increase volume on mortality, surgeon and
hospital volume
Model with adjustment for case mix Effect 1 95% CI
Volume of centre (increase of 10%) -4.31 -7.11 -1.15
Volume of surgeon (increase of 10%) -0.07 -2.67 1.14
1 Effect of 10% increase in volume on the odds of mortality
Coronary artery bypass surgery (isolated or in combination with heart valve
intervention) is probably one of the most studied procedures in the whole volume
outcome literature. It was first mentioned in the seminal article by Luft in 1979 which
lead, ten years later, to the first publicly available mortality rates presented per centre
and per surgeon in the State of New York. 98, 264 The US Agency for Healthcare Research
and Quality (AHRQ) also includes the volume of CABG in its list of quality indicators
(Inpatient Quality Indicator 5). 248 The AHRQ applies two thresholds to benchmark
hospitals: the lower threshold is >100 procedures per year, the upper threshold is >200
CABG per year. 29 The US Leapfrog Group uses the cut off of 450 operations per year
to select providers. 126
6.2.7.1 External validation of the definition of the procedure
The external validation of our definition process is based on the data from the Belgian
Working Group for Interventional Cardiology (BWGIC) and the Belgian Association for
Cardio-Thoracic Surgery (BACTS) for the year 2004, as published in KCE report 66
(table 1.2 on page 11). 265