Street-drug lethality index: A novel methodology for predicting unintentional drug overdose fatalities in population research

Estimating changes in overdose death rates from increasing methamphetamine supply in Ohio: Evidence from crime lab data

Background

We investigate the relationship between the supply of methamphetamine and overdose death risk in Ohio. Ohio and the overall US have experienced a marked increase in overdose deaths from methamphetamine combined with fentanyl over the last decade. The increasing use of methamphetamine may be increasing the risk of overdose death. However, if people are using it to substitute away from more dangerous synthetic opioids, it may reduce the overall risk of overdose death.

Methods

Ohio's Bureau of Criminal Investigation's crime lab data include a detailed list of the content of drug samples from law enforcement seizures, which are used as a proxy for drug supply. We use linear regressions to estimate the relationship between the proportion of methamphetamine in lab samples and unintentional drug overdose death rates from January 2015 through September 2021.

Results

Relatively more methamphetamine in crime lab data in a county-month has either no statistically significant relationship with overdose death rates (in small and medium population counties) or a negative and statistically significant relationship with overdose death rates (in large population counties). Past overdose death rates do not predict future increases in methamphetamine in crime lab data.

Conclusions

The results are consistent with a relatively higher supply of methamphetamine reducing the general risk of overdose death, possibly due to substitution away from more dangerous synthetic opioids. However, the supply of methamphetamine appears unrelated to the past illicit drug risk environment. The non-lethal and yet serious health effects of MA use were not explored and, thus, even if the presence of MA reduces the population-level overdose mortality rate, the rise of other adverse health effects may counteract any public health benefits of fewer deaths.

National and regional trends in fentanyl seizures in the United States, 2017-2023

BACKGROUND

Rates of synthetic opioid-related deaths over time and across regions have been compared within the US, but other indicator data could help inform prevention and harm reduction as well. We compared regional trends in fentanyl seizures to examine potential shifts in illicit fentanyl availability.

METHODS

Annual trends in fentanyl seizures were examined using data from High Intensity Drug Trafficking Areas for the US overall and by region from 2017 through 2023. Multiple measures included the number of seizures, the number of powder seizures, the number of pill seizures, the total weight of seizures, the number of pills seized, and the percentage of the number of pill seizures relative to the number of total seizures.

RESULTS

The percentage of seizures in pill form in the US increased from 10.3 % in 2017 to 49.0 % in 2023 (adjusted annual percentage change [AAPC]=25.2, 95 % CI: 17.6, 33.2), with 115.6 million individual pills seized in 2023. Pill weight related to total seizure weight also increased from 0.4 % to 54.5 % (AAPC=112.6, 95 % CI: 78.6, 153.2). In 2023, the plurality of seizures was in the West, in seven out of eight of our measures, with 77.8 % of seizures in the West being in pill form. Although the Midwest had lower prevalence of seizures than the West, there were notable increases in the Midwest in the number of pill seizures (AAPC=142.2, 95 % CI: 91.9, 205.8) and number of pills seized (AAPC=421.0, 95 % CI: 272.7, 628.4). Total weight of fentanyl seized increased the most in the West (AAPC=84.6, 95 % CI: 72.3, 97.8).

CONCLUSIONS

The number and size of fentanyl seizures is increasing in the US, with the majority of seizures, especially in pill form, in the West. Continued monitoring of regional shifts in the fentanyl supply can help inform targeted prevention and public health response.

Withdrawal catastrophizing scale: initial psychometric properties and implications for the study of opioid use disorder and hyperkatifeia

Background: Discovery of modifiable factors influencing subjective withdrawal experience might advance opioid use disorder (OUD) research and precision treatment. This study explores one factor - withdrawal catastrophizing - a negative cognitive and emotional orientation toward withdrawal characterized by excessive fear, worry or inability to divert attention from withdrawal symptoms.Objectives: We define a novel concept - withdrawal catastrophizing - and present an initial evaluation of the Withdrawal Catastrophizing Scale (WCS).Methods: Prospective observational study (n = 122, 48.7% women). Factor structure (exploratory factor analysis) and internal consistency (Cronbach's α) were assessed. Predictive validity was tested via correlation between WCS and next-day subjective opiate withdrawal scale (SOWS) severity. The clinical salience of WCS was evaluated by correlation between WCS and withdrawal-motivated behaviors including risk taking, OUD maintenance, OUD treatment delay, history of leaving the hospital against medical advice and buprenorphine-precipitated withdrawal.Results: WCS was found to have a two-factor structure (distortion and despair), strong internal consistency (α = .901), and predictive validity - Greater withdrawal catastrophizing was associated with next-day SOWS (rs (99) = 0.237, p = .017). Withdrawal catastrophizing was also correlated with risk-taking behavior to relieve withdrawal (rs (119) = 0.357, p < .001); withdrawal-motivated OUD treatment avoidance (rs (119) = 0.421, p < .001), history of leaving the hospital against medical advice (rs (119) = 0.373, p < .001) and buprenorphine-precipitated withdrawal (rs (119) = 0.369, p < .001).Conclusion: This study provides first evidence of withdrawal catastrophizing as a clinically important phenomenon with implications for the future study and treatment of OUD.

A scoping review of law enforcement drug seizures and overdose mortality in the United States

BACKGROUND

Leveraging law enforcement drug seizure data to better respond to the overdose crisis requires an understanding of available evidence and knowledge gaps regarding relationships between drug seizures and overdose mortality.

OBJECTIVE

This scoping review summarized peer-reviewed literature on associations between law enforcement drug seizures and drug-related mortality in the United States (US) in the era of illicitly-manufactured fentanyl, comparing study data sources, measures, methodologies, settings, and findings.

METHODS

We identified 388 non-duplicate records from three online databases searched on May 23, 2023. After title/abstract and full-text screening by two independent reviewers, 14 studies met the criteria for inclusion. The included studies tested the association between a measure related to law enforcement drug seizures and an overdose mortality outcome in the US and were published in English, in peer-reviewed journals, during or after 2013.

RESULTS

Four of 14 studies (29%) included data from the entire US, while the remaining studies focused on an individual state/city/county or a group of states/cities/counties. Synthetic opioid/fentanyl seizures represented the most frequently examined drug seizure category, and overdose deaths overall (involving any drugs) represented the most frequently examined outcome. Most studies used counts/rates of drug seizures, with fewer studies examining dosage/weight, drug combinations, the proportion of drug seizures involving a specific drug, or spatiotemporal distribution. The majority (86%) of studies reported at least one statistically significant positive association between a law enforcement drug seizure measure and an overdose mortality outcome, most consistently for fentanyl-related seizures. Results were relatively less consistent for seizures involving stimulants and other drugs.

CONCLUSIONS

Studies in this review provided consistent evidence that fentanyl-related seizure measures are positively associated with overdose mortality outcomes, despite the limitations inherent in drug seizure data, even in the absence of available information regarding seizure weight or dosage.

Drug supply measures and drug overdose mortality in the era of fentanyl and stimulants

Background

Illicitly-manufactured fentanyl and stimulants have replaced prescription opioids as the primary contributors to fatal overdoses in the United States (US), yet the street supply of these substances is challenging to quantify. Building on the foundation of prior research on law enforcement drug reports, the present study compares publicly available forensic laboratory drug report measures to identify which measures account for the most variation in drug overdose mortality between states, within states over time, and in various demographic groups.

Methods

Drug reports from the National Forensic Laboratory Information System and drug overdose mortality rates from the Centers for Disease Control and Prevention were examined for all US states and the District of Columbia, 2013-2021 (459 state-years). State- and year- fixed effects models regressed drug overdose mortality rates (in the overall population and subpopulations by sex, age, and race/ethnicity) on various drug report measures, including rates per population and proportional shares of drug reports positive for fentanyl/fentanyl-related compounds, heroin, cocaine, methamphetamine, and xylazine.

Results

For drug overdose death rates in the overall population and nearly all subpopulations examined by sex, race/ethnicity, and age, the model including all drug report proportional measures represented the best-performing model (as identified via the lowest Akaike Information Criterion and highest within R-squared value), followed by the model including only the fentanyl/fentanyl-related compounds proportion.

Conclusions

Findings support the utility of publicly available drug report composition measures, particularly the proportion of fentanyl/fentanyl-related compounds, as predictors of drug overdose mortality in the US and in various subpopulations.

Associations between opioid overdose deaths and drugs confiscated by law enforcement and submitted to crime laboratories for analysis, United States, 2014-2019: an observational study

Background

The overdose epidemic in the United States (US) continues to generate unprecedented levels of mortality. There is urgent need for a national data system capable of yielding high-quality, timely, and actionable information on existing and emerging drugs. Public health researchers have started using law enforcement forensic laboratory data to obtain surveillance information on illicit drugs. This study is the first to use drug reports from the entire US to examine correlations between a changing drug supply and increasing opioid-involved overdose deaths (OOD) on a national scale.

Methods

This study is observational and investigates associations between law enforcement drug reports and OOD for the US from 2014 to 2019. OOD data are from the Centers for Disease Control and Prevention's National Vital Statistics System restricted-use multiple cause of death files. The US Drug Enforcement Administration's National Forensic Laboratory Information System (NFLIS) contains forensic laboratory-tested drug exhibit information for the entire US (NFLIS-Drug). Counts of forensic laboratory reports and OOD were aggregated for each state by month, quarter, and year. A difference-in-differences framework was used to estimate contemporaneous and lagged associations.

Findings

Between 2014 and 2019 in the US, 249,522 OOD were reported, with the annual number nearly doubling from 28,723 to 50,179. OOD involving illicitly manufactured fentanyls (IMF) also increased substantially during this period, from 19.4% to 72.9%. In addition, 3,817,438 forensic laboratory reports in the US that were reported to NFLIS-Drug contained an opioid, stimulant, or benzodiazepine. Reports of fentanyl and fentanyl-related compounds (FFRC) had the strongest association with OOD. Each additional FFRC exhibit was associated with a 2.97% (95% CI: 1.7%, 4.1%) increase in OOD per 100,000 persons per quarter.

Interpretation

Adding to the emerging consensus, protracted growth in IMF supply was more strongly associated with OOD than all other illicit drugs reported to NFLIS-Drug over the study time period. Findings demonstrate NFLIS-Drug data usefulness for research that require proxy indicators for the illicit drugs supply. A concerted effort between public health and public safety to make NFLIS-Drug more timely could strengthen its utility as a national, public health, drug surveillance system.

Funding

Sangeetha Arctic Slope Mission Services, LLC, ASMS Contract No. ASM5-00017.

Xylazine in Drug Seizure Reports and Overdose Deaths in the US, 2018-2022

Xylazine is increasingly reported in street drugs and fatal overdoses in the United States (US), often in combination with synthetic opioids, yet state-level xylazine data are limited, hampering local public health responses. The present study analyzed 2018-2022 state-level data from the National Forensic Laboratory Information System (xylazine-positive reports of seized drugs analyzed by forensic laboratories), the Centers for Disease Control and Prevention (population estimates, synthetic opioid overdose mortality rates), and individual states' medical examiner/public health agency reports (numbers of xylazine-involved overdose deaths). An ordinary least squares regression model predicted state-level synthetic opioid overdose mortality rates by xylazine seizure report rates, adjusting for US Census Region. In 2018, relatively low rates of xylazine seizure reports were observed, with 21 states reporting zero xylazine seizures. In 2022, only three states reported zero xylazine seizures, and the highest xylazine seizure report rates (per 100,000 residents) were observed in New Jersey (30.4), Rhode Island (22.7), Maryland (18.9), Virginia (15.5), New Hampshire (13.0), and Ohio (10.9). Data on 2019-2022 xylazine-involved overdose deaths were available for 21 states/DC (60 state-years), with the highest 2022 xylazine-involved overdose death rates (per 100,000 residents) in Vermont (10.5) and Connecticut (9.8). Finally, in 2021, at the state level, each additional reported xylazine seizure per 100,000 residents was associated with a 2% higher synthetic opioid overdose mortality rate (b=0.02, robust standard error=0.01; p=0.049). Overall, study results emphasize xylazine's increasing involvement in US law enforcement drug seizure reports and overdose deaths, primarily in the East, yet also extending across the country.

Years of life lost due to unintentional drug overdose relative to the leading underlying causes of death in the United States: a comparative analysis of excess mortality 2017-2019

The present study aims to compare Years of Life Lost for unintentional drug overdose and the leading underlying causes of death in the United States annually from 2017 to 2019. Years of Life Lost provide valuable context to incident deaths when comparing the relative mortality burden of underlying causes of death. Prior research has shown unintentional drug overdose was the third leading cause of Years of Life Lost in the state of Ohio in 2017. However, this finding has yet to be replicated at the national level in the US. Death statistics for 2017-2019 were accessed via CDC WONDER. Years of Life Lost were calculated for unintentional drug overdose and each of the top five causes of incident deaths in the US during the study period. Unintentional drug overdose caused nearly seven million Years of Life Lost in the US during the three-year period of study and was the fourth leading cause of Years of Life Lost after cancer, heart disease and other accidents. Incidence alone provides an incomplete picture of the effect of unintentional drug overdose on overall mortality burden in the US. Years of Life Lost give critical context to the overdose crisis, underscoring unintentional drug overdose as a leading cause of premature mortality.

Years of Life Lost due to Unintentional Drug Overdose among Perinatal Individuals in the United States

BACKGROUND

The United States has one of the highest maternal mortality rates of developing countries, but the contribution of perinatal drug overdose is not known. Communities of color also have higher rates of maternal morbidity and mortality when compared to White communities, however the contribution due to overdose has not yet been examined in this population.

OBJECTIVES

To quantify the years of life lost due to unintentional overdose in perinatal individuals from 2010 to 2019 and assess for disparity by race.

STUDY DESIGN

This was a cross-sectional retrospective study with summary-level mortality statistics for the years 2010-2019 obtained from the Centers for Disease Control (CDC) Wide-Ranging Online Data for Epidemiologic Research (WONDER) mortality file. A total of 1,586 individuals of childbearing age (15-44 years) who died during pregnancy or six weeks postpartum (perinatal) from unintentional overdose in the United States from January 1, 2010 to December 31, 2019 were included. Total years of life lost (YLL) was calculated and summated for White, Black, Hispanic, Asian/Pacific Islander, and American Indian/Native Alaska women. Additionally, the top three overall causes of death were also identified for women in this age group for comparison.

RESULTS

Unintentional drug overdose accounted for 1,586 deaths and 83,969.78 YLL in perinatal individuals from 2010 to 2019 in the United States. Perinatal American Indian/Native American individuals had a disproportionate amount of YLL when compared to other ethnic groups, with 2.39% of YLL due to overdose, while only making up 0.80% of the population. During the last two years of the study, only American Indian/Native American and Black individuals had increased rates of mortality when compared to other races. During the ten-year study period, when including the top three causes of mortality, unintentional drug overdoses made up 11.98% of the YLL overall and 46.39% of accidents. For the years 2016-2019, YLL due to unintentional overdose was the third leading cause of YLL overall for this population.

CONCLUSIONS

Unintentional drug overdose is a leading cause of death for perinatal individuals in the United States, claiming nearly 84,000 years of life over a ten-year period. When examining by race, American Indian/Native American women are most disproportionately affected.

Association between law enforcement seizures of illicit drugs and drug overdose deaths involving cocaine and methamphetamine, Ohio, 2014-2019

BACKGROUND

The United States continues to experience a crisis of mounting opioid overdose deaths involving cocaine and methamphetamine (hereafter illicit stimulants). Law enforcement drug seizure data present a unique opportunity to examine the association between illicit-stimulant-involved overdose deaths (ISODs) and the illicit drug supply. Our objective is to better understand correlations between illicit drug market trends and increases in ISODs in Ohio in 2014-2019.

METHODS

This observational study analyzes the universe of ISODs and drug seizures in Ohio from 2014 to 2019. We use graphs and descriptive statistics to characterize trends over time and estimate a time series model of their association. ISODs were summed to yield monthly statewide counts of seizures containing methamphetamine, cocaine, illicitly manufactured fentanyl (IMF), and other non-IMF opioids (e.g., heroin). All rates were calculated per 100,000 persons.

RESULTS

Roughly 80% of ISODs in Ohio from 2014 to 2019 involved an opioid, with IMF co-occurring in 90% of ISODs by 2019. Methamphetamine and cocaine seizures containing IMF were associated with 0.439 (p < .01) and 0.457 (p < .01) additional deaths per 100,000 persons per month, respectively. IMF seizures not containing cocaine nor methamphetamine were also associated with additional ISODs (0.119, p < .01) and seizures of illicit stimulants not containing IMF were not associated with ISODs.

CONCLUSIONS

The number of ISODs was extremely high when IMF was co-involved and relatively low without IMF involvement. By demonstrating how supply-side trends correspond with ISOD rates, the current study bolsters the analytical utility of law enforcement seizures and complements growing literature in the field.

Classification accuracy and functional difference prediction in different brain regions of drug abuser prefrontal lobe basing on machine-learning

Taking different types of addictive drugs such as methamphetamine, heroin, and mixed drugs causes brain functional Changes. Based on the prefrontal functional near-infrared spectroscopy, this study was designed with an experimental paradigm that included the induction of resting and drug addiction cravings. Hemoglobin concentrations of 30 drug users (10 on methamphetamine, 10 on heroin, and 10 on mixed type) were collected. For these three types of individuals, the convolutional neural networks (CNN) was designed to classify eight Brodmann areas and the entire prefrontal area, and the average accuracy of the three classifications on each functional area was obtained. As a result, the classification accuracy was lower on the left side than on the right in the dorsolateral prefrontal cortex (DLPFC) of the drug users, while it was higher on the left than on the right in the ventrolateral prefrontal cortex (VLPFC), frontopolar prefrontal cortex (FPC), and orbitofrontal cortex (OFC). Then the differences in eight functional areas between the three types of individuals were statistically analyzed, and results showed significant differences in the right VLPFC and right OFC.