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

KCE Reports 113 Volume Outcome 215
b. Evaluation of surgeon volume can be performed at short term: in-hospital
mortality, 30-day or 90-day mortality, keeping in mind that evaluating
outcome beyond hospital discharge has the additional advantage of being
unaffected by differences in practice discharges across hospitals. Especially
for low-risk surgical procedures, evaluation of centre volume can require
several years of follow up, because the effect of centre volume is a
mixture of the effect of the surgeon volume (the experience) and the
effect of organisational aspects of the centres (such as process indicators,
compliance to guidelines, organization of care), which play a role on a
longer timeframe than surgery skills. To analyze outcomes beyond
hospitalisation, it is necessary to link MCD-MFD data to IMA data. One
shortcoming of these data is that the exact dates (of hospital admission
and of death) are not available, hence rending impossible to evaluate
outcomes at precise time points.
3. It is important to distinguish between the effect of the surgeon
volume (experience) and the effect of the hospital volume
(organisation of care in the broad sense). The relative importance of
surgeon or hospital volume is difficult to distinguish for infrequent
interventions where surgeon volume equals hospital volume. In addition, this
relative importance seems to vary according to the procedure. Two
extremes are carotid endarterectomy and lung cancer surgery. CEA, for
example, is technically demanding and any failure in surgical practice is
potentially catastrophic. Other hospital-based services, on the other hand,
are relatively less important i.e. most patients undergoing CEA do not
require intensive postoperative management. In the case of lung cancer
surgery, in contrast, patients rarely die because of direct technical
complications of the procedure itself. Since these patients more often die
from cardiac events, pneumonia and respiratory failure, hospital-based
services are very important. These services include, for example, intensive
care, pain management, respiratory care and nursing care.
4. Robust information on case mix is important. Patient characteristics and
disease severity should be available. Risk adjustment is an important issue in
volume outcome research because patients with severe co morbidity may be
unequally distributed between providers of low and high volume.
a. MCD data provide information on patient demographics and co
morbidities. A useful tool is the Charlson score, which has been validated
to predict 1-year mortality. It is a sum of some predefined weights
attributed to 17 specific conditions. The Charlson score can be computed
based on MCD data, but inherits their limitations i.e. it depends of the
quality and completeness of coding of co morbidities in each hospital. The
other drawback of MCD data, the impossibility to differentiate co
morbidities from complications, has been resolved in MCD since 2008.
b. The other part of the case mix adjustment, information on disease
severity, is not available in MCD data but can be retrieved in existing
registries, which typically record detailed clinical information.
• With respect to cancer, the Belgian Cancer Registry has detailed
information on tumour characteristics, and the linkage in our study
between MCD and BCR data for five conditions was successful. Stage was
still missing in a high proportion of cases (on data of 2004), but efforts are
currently made to enhance completeness of stage coding. In future, the
availability of an updated and complete register in combination with the
patient’s personal identification number will enable complete follow-up of
cancer patients in Belgium.