The data material is constructed via linkage of different data bases at patient level, made possible by the individual social security number.
Such information is essential for optimal policy design but remains beyond the reach of the data material currently at our disposal12.
The data material prepared as described above was subsequently used for statistical scrutiny of the three research questions of this study.
These weaknesses aside, the data material used in this study provides a strong basis for analysing cost drivers including salient quality variables.
The study is as such not an evaluation of performance, and the first-hand knowledge of context and familiarity with the data material may be seen as a strength to this descriptive observational study.
The data material indicates that the correspondence between core porosity and core permeability data is not perfect, but reasonable porosity permeability correlations may be obtained, despite the rather scattered data.
SINTEF Health Research for the use of the data material.
A population of 666 women constituted the data material.
SS, KK and CA collected and analysed the data material.
Since the data material is indirectly person-identifiable, it has been anonymized.
We consider it a strength to pursue the initial surprising findings in the data material.
