British Columbia Centre on Substance Use, 400-1045 Howe Street, Vancouver, BC, V6Z 2A9, Canada; Department of Medicine, University of British Columbia, 2775 Laurel Street, Vancouver, BC, V6H 0A5, Canada.
British Columbia Centre on Substance Use, 400-1045 Howe Street, Vancouver, BC, V6Z 2A9, Canada; Department of Sociology, University of British Columbia, 6303 NW Marine Dr., Vancouver, BC, V6T 1Z1, Canada.
Int J Drug Policy. 2022 Jul;105:103707. doi: 10.1016/j.drugpo.2022.103707. Epub 2022 Apr 30.
Increased drug-related harms, including overdoses (poisonings), have been reported in the days around income assistance payments, yet little is known about changes in the unregulated drug supply during this time. In this exploratory analysis, we investigated whether changes in the unregulated opioid drug supply are associated with income assistance payment weeks.
Using data from drug checking services in Vancouver, BC, we conducted modified Poisson and linear regression models to examine the association between income assistance payment weeks and three key outcomes: (1) proportion of fentanyl positivity among expected opioid samples, (2) fentanyl concentration among fentanyl-positive expected opioid samples, and (3) proportion of benzodiazepine positivity among expected opioid samples.
Between October 2017 and December 2019, 4306 (90.41%) of expected opioid samples tested positive for fentanyl, and the median fentanyl concentration was 7.0% (quartile [Q]1 - Q3: 5.1% - 9.8%). Income assistance payment week was associated with an increased prevalence of fentanyl positivity among expected opioid samples (prevalence ratio [PR]: 1.03; 95% confidence interval [CI]: 1.00, 1.05); however, we failed to find a statistically significant association between income assistance payment week and fentanyl concentration (regression coefficient: 0.70; 95% CI: 0.44, 1.09). Additionally, income assistance payment week was associated with an increased prevalence of benzodiazepine positivity among expected opioid samples (PR: 1.86; 95% CI: 1.07, 3.24).
These findings suggest that during income assistance payment weeks, there may be more fentanyl and benzodiazepines circulating in the unregulated opioid drug supply. The rise in fentanyl and benzodiazepine-adulterated opioids during income assistance payment weeks may be contributing to the increase in illicit drug overdoses seen during this time of the month.
在收入援助金支付前后的几天里，药物相关危害（包括过量用药）有所增加，但对于这段时间不受监管的毒品供应情况变化知之甚少。在这项探索性分析中，我们研究了不受监管的阿片类药物供应变化是否与收入援助金支付周有关。
我们使用不列颠哥伦比亚省温哥华毒品检测服务的数据，采用修正后的泊松和线性回归模型，研究收入援助金支付周与三个关键结果之间的关联：（1）预期阿片类药物样本中芬太尼阳性的比例；（2）芬太尼阳性的预期阿片类药物样本中的芬太尼浓度；（3）预期阿片类药物样本中苯二氮䓬类药物阳性的比例。
在 2017 年 10 月至 2019 年 12 月期间，4306 份（90.41%）预期阿片类药物样本检测出芬太尼阳性，芬太尼的中位数浓度为 7.0%（四分位距[Q1-Q3]：5.1%-9.8%）。收入援助金支付周与预期阿片类药物样本中芬太尼阳性的比例增加有关（优势比[PR]：1.03；95%置信区间[CI]：1.00，1.05）；然而，我们没有发现收入援助金支付周与芬太尼浓度之间存在统计学上的显著关联（回归系数：0.70；95%CI：0.44，1.09）。此外，收入援助金支付周与预期阿片类药物样本中苯二氮䓬类药物阳性的比例增加有关（PR：1.86；95%CI：1.07，3.24）。
这些发现表明，在收入援助金支付周期间，不受监管的阿片类药物供应中可能有更多的芬太尼和苯二氮䓬类药物。在这个月的这个时候，芬太尼和苯二氮䓬类药物掺假阿片类药物的增加可能是导致非法药物过量的原因之一。
