Adulteration of urine drug testing--an exaggerated cause of concern

In a study performed at a Stockholm clinic for young people with drug abuse problems, where urine adulteration was suspected to be fairly frequent, a total of 594 patient specimens were subjected to Adultacheck test strip screening for nitrite, glutaraldehyde, pH, and creatinine. Creatinine measurement was also performed at the laboratory, together with drug screening using EMIT reagents, and a subsample was spiked with phencyclidine to verify EMIT test function. The frequency of dilute urine (creatinine < 4 mmol/L) was 11%. Otherwise no evidence of urine adulteration was observed. Thus the Adultacheck strip might be useful in detecting dilute urine specimens already at the clinic, though the test strip levels did not agree well with the respective laboratory results. It was concluded that adulteration of urine specimens was not common at the clinic, and that specimen collection for urine drug testing could be performed in a reliable manner.