High concordance between urine toxicology results and self-reported fentanyl use in Nevada and New Mexico.

BACKGROUND: Co-use of stimulants and opioids is often deliberate. However, the possibility remains that some people are unintentionally consuming fentanyl. To advance understanding of overdose risk, we examined the rate of concordance between self-reported fentanyl use and corresponding urine toxicology screen results. METHODS: Between August 2022-August 2023, 411 participants (adults who reported any non-medical drug use in the past three months) in Nevada and New Mexico completed a cross-sectional survey, of whom 64% (n = 270; the analytical sample) also completed a urine toxicology screen, which detects fentanyl use in the past three days. Positive predictive value, negative predictive value, sensitivity, and specificity were calculated using self-reported past three-day fentanyl use (yes/no) and urine toxicology screen results for the presence of fentanyl (positive/negative). RESULTS: Of the 270 participants who provided a urine sample, 268 are included in the descriptive statistics (two with inconclusive urine toxicology screen results were excluded). Of the 268 participants, 146 (54.5%) had a fentanyl-positive urine toxicology screen result, 122 (45.5%) had a fentanyl-negative urine toxicology screen result, 137 (51.1%) reported past three-day fentanyl use, and 130 (48.5%) reported no past three-day fentanyl use. Only 6.9% of those with a fentanyl-positive urine toxicology screen did not report recent fentanyl use. The sensitivity of self-reported fentanyl use was 93%, specificity was 97%, positive predictive value was 97%, and negative predictive value was 92%. DISCUSSION: The rate of unanticipated exposure to fentanyl (that is, positive urine screen and negative self-report) in this sample was low, at 6.9%. This runs counter to the national narrative that there is widespread unknown contamination of fentanyl in the drug supply. CONCLUSION: Future research is needed to further explore how people who use multiple substances interpret their overdose risk and what harm reduction methods they employ.

The Cognitive Structure of the Basketball Free Throw in Adolescent Physical Education Students.

In adult performers, research suggests that mental representations (MRs) mediate performance of skilled movement. During adolescence, cortical brain areas responsible for generating MRs develop rapidly along with limb size, which, together, may affect movement and movement representations. The aim of this study was to examine the relationship between adolescent MRs and free-throw shooting expertise. Using structural dimensional analysis of MRs, skilled (n = 11) and less skilled (n = 11) participants sorted free-throw submovements according to their relatedness in movement execution. Data were analyzed using a hierarchical cluster analysis, factor analysis, and invariance test to examine between-group cluster comparisons. Cluster solutions for the skilled and less skilled participants were significantly variant (λ = 0.56). This method of measuring MRs distinguished expertise-related differences in MRs in an adolescent population. Findings may influence methods in which practitioners detect motor-planning faults, track development, and provide feedback to trainees.