Diagnostic error as a result of drug-laboratory test interactions

Abstract

Background Knowledge of possible drug-laboratory test interactions (DLTIs) is important for the interpretation of laboratory test results. Test results may be affected by physiological or analytical drug effects. Failure to recognize these interactions may lead to misinterpretation of test results, a delayed or erroneous diagnosis or unnecessary extra tests or therapy, which may harm patients. Content Thousands of interactions have been reported in the literature, but are often fragmentarily described and some papers even reported contradictory findings. How can healthcare professionals become aware of all these possible interactions in their individual patients? DLTI decision support applications could be a good solution. In a literature search, only four relevant studies have been found on DLTI decision support applications in clinical practice. These studies show a potential benefit of automated DLTI messages to physicians for the interpretation of laboratory test results. All physicians reported that part of the DLTI messages were useful. In one study, 74% of physicians even sometimes refrained from further additional examination. Summary and outlook Unrecognized DLTIs potentially cause diagnostic errors in a large number of patients. Therefore, efforts to avoid these errors, for example with a DLTI decision support application, could tremendously improve patient outcome.

Drug interference with biochemical laboratory tests

“…An extensive on-line database of the effects of drugs, disease, preanalytical variables, and herbals on laboratory tests, created by principal editor DS Young, contains information on more than 135,000 effects on more than 5,000 tests, with > 50,000 DLTIs (19,31). Table 1 presents the selection of the most useful DLTIs databases with internet addresses.…”

“…Results of numerous routinely performed and highly specialized BLTs in serum and other biological material can be influenced by one or more drugs that are prescribed to patients. Therefore, DLTIs represent an important source of diagnostic and/or therapeutic errors ( 19 ). This emphasizes the importance of knowledge and continual education regarding the possible DLTIs, for medical doctors, pharmacists and laboratory specialists ( 20 ).…”

“…The first type of DLTIs is the most frequent category that refers to the influences of drugs and their metabolites on BLTs, which are independent of the BLT method used in laboratory. This physiological type of DLTIs can be identified when the change of laboratory parameter under the influence of drug is expected (the intended effects of drugs) ( 19 ). An illustrative example of this is the decrease of thyroid stimulating hormone upon thyroid hormone replacement therapy ( 19 , 42 ).…”

“…This physiological type of DLTIs can be identified when the change of laboratory parameter under the influence of drug is expected (the intended effects of drugs) ( 19 ). An illustrative example of this is the decrease of thyroid stimulating hormone upon thyroid hormone replacement therapy ( 19 , 42 ). On the other hand, the identification of DLTI is difficult in case of unwanted or toxic drug effects such as idiosyncratic drug reactions (IDR) ( 43 ).…”

“…Recently published data indicate that additional unnecessary diagnostic procedures are carried out due to DLTI, which is well known in medical practice ( 19 ). In patients with neuroendocrine tumors (NETs), standard of care requires testing of the most important biochemical tumour markers: chromogranin A (CgA, diagnostic sensitivity and specificity within the range of 60-90%) and neuron-specific enolase (NSE) ( 45 ).…”