Sharip Akbar, Razavi Roshan
Occupational and Environmental Medicine, Department of Preventive Medicine, Loma Linda University, 24785 Stewart Street, Evans Hall, Suite 204, Loma Linda, CA, 92354, USA.
Occupational Medicine, Antioch Medical Center, Kaiser Permanente, 4501 Sand Creek Road, Antioch, CA, 94531, USA.
J Occup Med Toxicol. 2025 Sep 8;20(1):29. doi: 10.1186/s12995-025-00468-3.
This study examines trends in delta-9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) positivity rates in pre-employment urine drug screenings at a single university-based hospital occupational medicine clinic from 2017 to 2022, following California's recreational cannabis legalization in 2016, with sales beginning officially on January 1, 2018.
Retrospective analysis of 21,546 de-identified urine drug screenings from 2017 to 2022 was conducted. Initial screening used instant urine drug immunoassays (50 ng/mL cutoff for THC-COOH), followed by confirmatory gas chromatography-mass spectrometry (15 ng/mL cutoff). Positivity rates were calculated annually, and descriptive statistics summarized age and gender distributions among positive cases. The Cochran-Armitage trend test assessed temporal trends.
Of 21,546 screenings, 92 (0.44%) were THC-COOH-positive. The positivity rate increased from 0.12% (4/3,215) in 2017 to 0.94% (45/4,784) in 2022 (Cochran-Armitage, Z = 5.19, p < 0.001), a 683.33% relative increase (absolute change: 0.82%). Among positive cases, 76% were aged 20-39 (mean: 29.00 years, SD = 9.5), and the female proportion rose from 25.00 to 62.22%. Median THC-COOH levels ranged from 60.00 to 176.50 ng/mL (overall: 145.0, IQR: 309.5).
THC-COOH positivity rates increased significantly post-legalization, potentially influenced by increased cannabis use. Urine tests detect past use, not impairment, highlighting the need for impairment-focused testing per Assembly Bill 2188 (2024). Missing total sample demographic data limit age/gender subgroup analyses.
本研究调查了2016年加利福尼亚州娱乐用大麻合法化（2018年1月1日正式开始销售）后，一所大学附属医院职业医学诊所2017年至2022年入职前尿液药物筛查中δ-9-四氢大麻酚-9-羧酸（THC-COOH）阳性率的变化趋势。
对2017年至2022年21546份匿名尿液药物筛查进行回顾性分析。初始筛查采用即时尿液药物免疫分析（THC-COOH的临界值为50 ng/mL），随后采用气相色谱-质谱确证分析（临界值为15 ng/mL）。每年计算阳性率，并通过描述性统计总结阳性病例的年龄和性别分布。采用 Cochr an-Armitage趋势检验评估时间趋势。
在21546份筛查中，92份（0.44%）THC-COOH呈阳性。阳性率从2017年的0.12%（4/3215）增至2022年的0.94%（45/4784）（ Cochr an-Armitage检验，Z = 5.19，p < 0.001），相对增幅为683.33%（绝对变化：0.82%）。在阳性病例中，76%的年龄在20至39岁之间（平均年龄：29.00岁，标准差 = 9.5），女性比例从25.00%升至62.22%。THC-COOH水平中位数在60.00至176.50 ng/mL之间（总体：145.0，四分位数间距：309.5）。
合法化后THC-COOH阳性率显著上升，可能受到大麻使用增加的影响。尿液检测检测的是过去的使用情况，而非损伤情况，这凸显了根据第2188号议会法案（2024年）进行以损伤为重点检测的必要性。缺少总体样本人口统计学数据限制了年龄/性别亚组分析。
