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

38 Volume Outcome KCE reports 113
Another indicator of data quality is the proportion of records with missing values for
certain variables. In the 2004 dataset, 100% completeness was obtained for tumour
localisation, histology, behaviour, incidence date, sex and age of the patient.
Basis of diagnosis reached 99.3% completeness. Primary tumour localisation was well
specified in 99.9% of the cases, and histology in 95.5%. Data on the WHO performance
score and treatment of the tumour were missing in respectively 46 and 39% of cases,
which makes these variables unreliable. Information on laterality and stage is often not
complete either; 34.0% of cases related to pair organs lack information on laterality;
29.9% of records where stageable tumours are concerned are missing information on
the stage (CombStage). 108
Table 4.2 shows the percentage of well specified laterality and availability of stage
information for the tumours that will be analyzed in this report. The Clinical stage
(cStage) is based on the available information obtained before resection surgery i.e. by
physical examination, radiologic examination and endoscopy. Pathologic stage (pStage)
adds additional information gained by histopathologic examination of the tumour. The
BCR merges both stages for reporting reasons into the Combined Stage (CombStage).
During this merge, the pathologic stage prevails over the clinical stage, except when the
clinical TNM is stage IV. In this report, only the Combined TNM stage will be used for
risk adjustment. Tumour sites with less surgical treatment such as oesophagus, pancreas
and lung have, in general, a higher percentage of cStage and a lower percentage of
pStage. For tumours located at colon, rectosigmoid junction, bronchus and lung and
breast, at least 70% of records contain information on the CombStage is available. For
oesophageal and pancreas tumours, on the other hand, the % CombStage is respectively
60.9 and 64.9% which can cause problems when used for risk adjustment.
Table 4.2: Percentage of well specified laterality and availability of stage
information, 2004, Belgium (Belgian Cancer Registry) 58
Localisation %
% cStage % pStage %
Laterality
CombStage
C15 Oesophagus NA 54.4 21.9 62.0
C18 Colon NA 28.3 73.9 79.5
C19 Rectosigmoid junction NA 39.9 83.0 91.8
C25 Pancreas NA 52.2 26.8 65.2
C34 Bronchus and lung 78.7 65.6 18.2 69.8
C50 Breast
NA = not applicable
92.8 59.5 78.4 87.2
4.1.4 Authorization from Privacy Commission
The authorization to access and link these three databases was granted by the Sectorial
Committee Social Security and Health of the Belgian Privacy Commission on April 8,
2008.