Clinical value of drugs of abuse point of care testing in an emergency department setting

Objective Toxicology screening tests for drugs-of-abuse and therapeutic drugs in urine (TST-U) are often used to assess whether a patient's clinical condition can be explained by the use of drugs-of-abuse (DOA) and/or therapeutic drugs. TST-U have clinical value when they support clinical decision making by influencing diagnosis and patient care. We aim to quantify the influence of TST-U results on diagnosis and patient care in an emergency department. Our secondary objective is to identify specific patients for which a TST-U is most warranted or mostly unhelpful. Methods This prospective observational study was performed at the emergency department of a middle-sized urban teaching hospital. A point of care TST-U has been used in this department for three years. When a TST-U is considered indicated by a physician, the influence of the TST-U result on diagnosis and patient care is quantified before and after the test results are available, by means of a questionnaire. Urgency and complaints upon admission have also been registered. Results Of 100 TST-U results 37% were reported having a substantial influence on diagnosis and 25% on patient care. TST-U had a substantial influence on diagnosis in 48% of patients with decreased consciousness, 47% of patients with psychiatric symptoms and in 47% of patients with "other" complaints. In this last category patients with neurological symptoms benefited most. In patients who were already suspected to be intoxicated, only 18% of the TST-U results had substantial influence on diagnosis. Conclusions The use of point of care TST-U in an Emergency Department helps physicians to understand the clinical condition of a patient. They influence the way a patient is treated to a lesser extent. These tests are most helpful in patients with decreased consciousness, psychiatric or neurological symptoms and mostly unhelpful in patients who, upon admission, are already known to be intoxicated.