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

KCE Reports 113 Volume Outcome 79
Table 5.31 shows the results from logistic regression (with GEE adjustment for
clustering of patients within centres). Patients operated by surgeons performing less
than 6 interventions per year have a 50% higher odds of mortality than patients
operated by surgeons performing at least 6 interventions per year, taking into account
patient and tumour characteristics: odds ratio and 95% CI 1.51 (1.06, 2.16).
Table 5.31: Pancreatic cancer surgery: Correlation-corrected logistic
regression (GEE) estimates of determinants of 2-year mortality
Model without adjustment for case mix
Factor OR 95%CI
Surgeon Volume 1-5/year 1.80 1.06 3.07
≥ 6 /year 1.00 1.00 1.00
Model with adjustment for patient characteristics (MCD data)
Surgeon Volume 1-5/year 1.54 1.02 2.34
≥ 6 /year 1.00 1.00 1.00
Sex male vs female 1.30 0.83 2.05
Age increase of 1 yr 1.03 1.00 1.06
Principal Duodenum vs Pancreas 1.19 0.38 3.75
Diagnosis Extrahepatic bile ducts or Ampulla of
Vater versus Pancreas
0.42 0.22 0.79
Charlson score increase of 1 1.07 0.79 1.46
Model with adjustment for patient and tumour characteristics (MCD and
BCR data)
Surgeon Volume 1-5/year 1.51 1.06 2.16
≥ 6 /year 1.00 1.00 1.00
Sex male vs female 1.46 0.90 2.36
Age increase of 1 yr 1.04 1.00 1.08
Principal Duodenum vs Pancreas 1.09 0.34 3.43
Diagnosis Extrahepatic bile ducts or Ampulla of
Vater versus Pancreas
0.42 0.19 0.94
Charlson score increase of 1 1.07 0.78 1.46
Stage
unknown 1.20 0.52 2.74
IV 2.06 0.60 7.08
III 4.55 1.42 14.62
II 2.35 1.12 4.94
0-I 1.00 1.00 1.00
5.3.7 Discussion
5.3.7.1 External validation of the definition of the procedure
According to the Belgian Cancer Registry, there were 1 080 new cases of pancreas
cancer in Belgium in 2004. See Table 5.1 (page 45). In the 2004 Minimal Clinical Data
(MCD), we identified 1 526 patients with the principal diagnosis of malignant neoplasm
of pancreas (see Table 5.19, page 66). The higher number of patients in the MCD is
explainable by the fact that these hospital stays are not restricted to patients whose
cancer started in 2004.
The study by Topal et al. supplies us with reference material. 156 Topal and colleagues
obtained minimal clinical data (MCD) on all pancreaticoduodenectomies (PDs)
performed in Belgium between 2000 and 2004. A total of 1 842 PDs were registered
based on ICD-9-CM procedure code 527 and/or NIHDI billing code 242023. When we
compare these selection criteria with ours (see Table 5.18), we notice that Topal et al.
focused on only one operative technique, i.e. the pancreaticoduodenectomy (the
Whipple procedure), which is the surgical procedure to remove the head of the
pancreas. On the other hand, however, they did not select on principal diagnosis and
therefore included patients with peripancreatic cancer or even with a disorder that is
not cancer related such as chronic pancreatitis. Considering these differences in patient
selection, it seems justifiable that Topal’s absolute number of patients (1 842 over five
years) is slightly higher than ours (320 in one year, see Table 5.19).