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