Since 2011 Statistics Netherlands is responsible for the calculation of the Hospital Standardised Mortality Ratio (HSMR) for the Dutch hospitals. Since there were some indications that there are quality issues with some of the variables used in the calculation of the HSMR, it was decided to investigate the quality of these variables.
The variable investigated in this paper are the comorbidities and urgency of the admission, i.e. whether the admission was planned or not.
