Abstract
Test indices are often determined by comparing test results of healthy persons with
test results of patients known to have the disease. However, the patient population
for which the test is ordered in clinical practice often differs from the study population
on which the test indices are based. Hence, these indices are not applicable to clinical
practice and should be recalculated using data from daily clinical practice. Two major
problems of using routinely collected data are discussed: the assessment of the final
health status and tracing the reason for ordering the test. Prior considerations are
given to the use of hospital information systems (HIS) to sample the patient population
that is desired and to collect the necessary data for calculating test indices. We
investigated whether the HIS of Leiden University Hospital (which is presented as
an example) can be used to calculate the indices of clinical laboratory tests, histopathologic
examinations and radiodiagnostic investigations. The results indicate that the registration
of diagnoses must be improved and that a way must be found to capture the implicit
reasoning for ordering diagnostic tests.
Key-Words
Hospital Information Systems - Diagnoses Registration - Diagnostic Test Indices -
Systematic Errors
