Outcome measures: The primary outcome measures are prevalence of positive tests and windows of drug detection (based on concentrations in the biological matrix) of methamphetamine, l-amphetamine, morphine, and codeine in blood, OF, and urine. Secondary outcome measures are 1) performance of 2 OF collection devices (Quantisal and Oral-Eze) and an on-site OF screening test (Draeger Drug Test 5000) in comparison to liquid chromatography-tandem mass spectrometry (LCMSMS), and performance of urine screening test in comparison to gas chromatography-mass spectrometry (GC-MS). Performance parameters are prevalence of positive tests at each time point, windows of drug detection, sensitivity, and specificity for l-methamphetamine, l-amphetamine, morphine, and codeine in OF and urine. Cutoff concentrations for each matrix are those specified in the Mandatory Guidelines for Federal Workplace Drug Testing Programs; 2) detection of d-methamphetamine in any blood, OF and urine specimen; and 3) time course of these analytes in blood for comparison to other matrices, especially oral fluid/blood ratios.