PROJECT RESIN: This study is examining the reliability, validity, and acceptability of a novel visual scale for estimating daily methamphetamine use among people who use methamphetamine.
Methamphetamine is a widely used psychostimulant associated with substantial cardiovascular and neuropsychiatric morbidity. The toxic effects of methamphetamine are dose-dependent, but clinical trials of interventions for methamphetamine use disorder often rely on urine drug screening as a primary outcome. Urine drug screening provides qualitative results and can remain positive for 5-7 days after using methamphetamine, thus limiting its use in trials that seek to measure use reduction and not only abstinence as a treatment outcome. Existing methods of measuring the frequency and amount of methamphetamine use include timeline follow-back (TLFB), which provides only days of use without any assessment of amount used each day, and hair sampling analysis, which may be able to demonstrate within-subject reduction in use over time but is impacted by numerous variables (including age, sex hormones, presence of hair, willingness to provide hair, hair color, and exposure to secondhand methamphetamine smoke) that limit its widespread use and inter-person reliability. To address this gap in methods for measuring reductions in methamphetamine use, we developed a novel visual scale that uses measured quantities of a methamphetamine analog (crystallized phenethylamine hydrochloride) encased in transparent polyester resin blocks, similar to food intake visual scales that use three-dimensional models of food portions. The purpose of this study is to assess the reliability, validity, and acceptability of the methamphetamine analogue visual scale (MAVS) among people who use methamphetamine (PWUM) with the hope of using the scale in future trials of pharmacotherapies for methamphetamine use disorder.
Study Type
OBSERVATIONAL
Enrollment
100
SFDPH Center on Substance Use and Health
San Francisco, California, United States
Reliability - Timeline Follow-back
The methamphetamine analog visual scale (MAVS) will be administered with the timeline follow-back (TLFB) at V0 and V1, which are 7-14 days apart. Each TLFB will assess 30 days prior to the date of assessment. The reliability outcome will compare within-subject reliability of meth use on overlapping days of TLFB using MAVS.
Time frame: Conducted at enrollment (V0) and follow-up (V1) to record meth use 30 days from those dates. The data will be collected as amount per day for 30 days.
Validity - Hair Sample
To assess validity, we will compare the hair sampling analysis and self-reported meth use via the MAVS/TLFB. Methamphetamine levels are determined by liquid chromatography tandem mass spectrometry (LC/MS/MS) using a Micromass Quattro Ultima and Shimadzu HPLC system equipped with a Phenomenex Synergi Polar-RP column (4.6 x 150 mm, 4 μm particle size), a mobile phase system consisting of acetonitrile:water:trifluoro acetic acid (20:80:0.05), and mass spectrometric detection with positive ionization by electrospray ionization and mass scanning by multiple reaction monitoring (\[M+H\]+ transitions of 150/119 (Q1/Q3) m/z for methamphetamine and 159/125 m/z for deuterated methamphetamine). The standard curve range of methamphetamine by LC/MS/MS analysis is 0.00800 nanograms (ng)/mg (lower limit) to 3.20 ng/mg of hair.
Time frame: Hair sample will be collected at the enrollment visit
Validity - Weighted Surrogate Assessment
Participants will work with the researchers to measure out a quantity of a non-psychoactive drug surrogate onto a physical milligram scale until the participant reports that the quantity matches their daily use. The min value of this scale is 0 and there is no max value. The actual score does not represent a better or worse outcome, rather we are comparing it to the reported value. To avoid potential use triggers associated with this procedure, it will be performed in a professional and clinical fashion, with the phenethylamine kept in laboratory glassware and handled with gloves and tweezers. This will be compared to the reported value to assess validity. This will be conducted at V0 and V1.
Time frame: At enrollment visit (V0) and at follow-up visit (V1). The data will be collected as amount per day for the most recent day of use.
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Acceptability Questionnaire
A questionnaire will be administered to assess the acceptability of the MAVS among people who use methamphetamine. This will be performed V1 and will consist of several 5-point Likert scale questions on the MAVS' ease of use, relevance to use patterns, and whether seeing the drug surrogate triggers a desire to use. A higher value on the scale measures higher acceptability.
Time frame: Follow-up visit (V1). The questionnaire will cover the time frame of the study, which will be 7-14 days.