Individuals Dying of Overdoses Related to Pharmaceutical Opioids Differ from Individuals Dying of Overdoses Related to Other Substances: A Population-Based Register Study

Leveraging pooled medical examiner records to surveil complex and emerging patterns of polysubstance use in the United States

BACKGROUND

The United States (US) is an extreme global outlier for drug-related death rates. However, data describing drug-related deaths are generally available only on an 8-13-month lag. Furthermore, granular details about substance-involvement are often not available, which particularly stymies efforts to track fatal polysubstance and novel psychoactive substance use. Detailed medical examiner records provide a powerful source of information for drug-related death surveillance, but have been underutilized.

METHODS

We pooled medical examiner data from five US states and 14 counties that together comprise 18% of the US population to examine demographic, geographic, and drug-specific trends in polysubstance drug-related deaths. We employed mixed effects logistic regression to identify demographic factors associated with polysubstance rather than single substance drug-related deaths. We assessed the correlations between drug classes and described geographic variation in the prevalence of specific drugs and the presence of novel and emerging psychoactive substances.

RESULTS

Our sample included 73,077 drug-related deaths from 2012 through early 2022. Nearly two-thirds of drug-related deaths were polysubstance-involved, with the number and percentage growing annually. High percentages of polysubstance drug-related deaths were observed in both urban and rural jurisdictions. After adjusting for year and jurisdiction, female, American Indian and Alaska Native, and White individuals had the most elevated odds of polysubstance drug-related deaths. Drug-related deaths involving benzodiazepines or opioids, whether pharmaceutical or illicit, and other pharmaceutical drugs were most likely to have polysubstance involvement, while methamphetamine-involved deaths were least likely to involve multiple substances. Strong correlations were observed between prescription opioids and prescription benzodiazepines, fentanyl and xylazine, and designer benzodiazepines and novel synthetic opioids.

CONCLUSIONS

Analysis of detailed medical examiner records reveals the breadth and complexity of polysubstance drug-related deaths in the US. Future efforts to use this unique resource can improve population-based surveillance of drug-related deaths to better tailor interventions and solutions to this critical health crisis.

Psykiske lidelser og plager ved vedvarende opioidbruk for langvarige ikke-kreftrelaterte smerter – en registerstudie

Background

Knowledge of mental disorders among patients with persistent opioid use for the treatment of chronic non-cancer pain is essential, as mental disorders and symptoms can exacerbate or perpetuate pain and impact on the ability of patients to manage their illness. We have studied the prevalence of mental disorders and symptoms, including substance use disorders, in patients with persistent opioid use in 2019.

Material and method

Persons ≥ 18 years with persistent opioid use and persons ≥ 18 years with at least one registered mental disorder in the specialist healthcare service in 2019 were included. Data were retrieved from national health registries in Norway. Patients who received opioids reimbursed for the treatment of chronic pain were compared with those who received opioids without reimbursement.

Results

The prevalence of mental disorders and symptoms was 34 % among 14 403 persons who received reimbursed opioids, and 42 % among 38 001 persons who received opioids without reimbursement. This is equivalent to a two to threefold increase in prevalence compared to the general population. There was a particularly higher prevalence of anxiety disorders and substance use disorders. The prevalence of mental disorders and symptoms was highest in the age group 18-44 years (49-55 %).

Interpretation

Among patients with persistent opioid use, a large proportion had mental disorders and symptoms, which are known risk factors for developing problematic opioid use and opioid use disorder.

Patterns of filled prescriptions and the association with risk of drug-induced death. A population-based nested case-control register study

PURPOSE

Opioid analgesics (OA) and other pharmaceuticals have been associated with drug-induced deaths. However, there is a lack of knowledge regarding patterns of use of these pharmaceuticals in the population and regarding such associations. We identify and describe subgroups of people with different patterns of filled prescriptions of OA and other relevant pharmaceuticals and examine associations with drug-induced deaths. In addition, we estimate the proportion of drug-induced deaths with a filled OA prescription and OA as cause of death.

METHODS

A Norwegian population-based nested case-control register study with cases (drug-induced deaths 2010-2018, N = 2388) and population controls matched for age, gender and year of inclusion (N = 21 465). Patterns of filled prescriptions for opioid analgesics (OA), benzodiazepines and benzodiazepine-related drugs, gabapentinoids, ADHD medication and antidepressants/antipsychotics were explored by k-means cluster analysis. Associations with drug-induced deaths were estimated by conditional logistic regression adjusted for sociodemographic characteristics. Overlap of filled OA prescriptions and OA as cause of death was estimated.

RESULTS

Five clusters were identified: 'few prescriptions', 'weak OA', 'ADHD medication', 'sedative/psychiatric morbidity' and 'strong OA'. The 'strong OA' cluster had higher socioeconomic status compared to the other groupings. The risk of drug-induced death was also highest in this cluster (OR = 35.5; CI 25.6-49.3) and, for 68% (CI 64-73) of cases, filled prescriptions for OA was indicated as the underlying cause of death.

CONCLUSIONS

The cluster analysis identified a subgroup with filled prescriptions of OA and other pharmaceuticals and a higher socioeconomic status than other subgroups. This subgroup had a high risk of drug-induced death that needs to be addressed.

No decline in drug overdose deaths in Norway: An ecological approach to understanding at-risk groups and the impact of interventions

Aim: This Norwegian case study examines groups at risk of drug overdose deaths, evidence-based harm reduction interventions, low-threshold services and treatment implemented, as well as trends in drug overdose deaths between 2010 and 2021. We aimed to explore the relevance of interventions for at-risk groups and discuss their potential impact on drug overdose trends. Method/data: Using an ecological approach, we analysed the following: (1) groups identified through latent profile analysis (LPA) among a sample of 413 high-risk drug users collected in 2010-2012, supplemented with other relevant studies up to 2021; (2) published information on harm-reduction interventions, low-threshold services and treatment in Norway; and (3) nationwide drug overdose mortality figures supplemented with published articles on the topic. Results: High-risk drug users in 2010-2012 commonly engaged in frequent illegal drug use, injecting and poly-drug use (including pharmaceutical opioids), which continued into following decade. The interventions implemented between 2010 and 2021 were relevant for at-risk groups identified in the surveys. However, there was no decrease in the trend of drug overdose deaths up to 2021. While relevant interventions may have mitigated a theoretical increase in mortality, new at-risk groups may have contributed to fatal outcomes associated with pharmaceutical opioids. Conclusion: The interventions were relevant to the risk groups identified among high-risk drug users and potentially effective in preventing an increase in drug overdose trends. However, tailored interventions are needed for individuals at risk of death from prescribed opioids. Comprehensive studies encompassing all at-risk populations, including both legal and non-medical users of prescription opioids, are needed.

Mortality risk and causes of death among people who use opioids in a take-home naloxone cohort

BACKGROUND

People who use opioids (PWUO) have an excess mortality from a range of causes. The cumulative effect of behavioral, social, and health risk factors complicates the interpretation of the effects of suitable interventions. This study explores mortality causes among a cohort of PWUO in the take-home naloxone (THN) program.

METHODS

This was a prospective cohort study of PWUO who received THN between 2015 and 2023. Participant data was linked with death registry data. Crude mortality rates and standardized mortality ratios (SMRs) were calculated for all causes, internal causes, and accidental opioid overdoses (AOOs). In addition to age and gender, risk factors like main route of administration, polydrug use, self-experienced overdoses, and using while alone were fitted in a Cox Regression model to explore factors associated with mortality.

RESULTS

The 2194 participants had a considerably higher mortality ratio for all causes investigated when compared to the general population (SMR=10.9, 95 % CI = 9.3,12.6). AOOs were the most prevalent cause of death (49 %). Those who reported frequent opioid use while alone had an elevated risk of dying of 2.6 (95 % CI = 1.1,6.4) compared to those who never used while alone.

CONCLUSIONS

Frequent opioid use while alone was associated with elevated mortality risk, supporting the importance of overdose prevention education with naloxone distribution, and additional efforts to improve environmental and social areas for safer drug-use practices among PWUO. The variety of mortality causes found in this study illustrates the need for multifaceted and targeted interventions for people at risk of overdosing.

Fatal drug overdoses in individuals treated pharmacologically for chronic pain: a nationwide register-based study

INTRODUCTION

Chronic pain patients may be at an increased risk for drug overdoses as a result of comorbid psychiatric disorders and treatment with risk-increasing prescription medications, such as opioids. We aimed to characterise fatal drug overdoses and investigate factors associated with the deaths among individuals who had been treated pharmacologically for chronic pain.

METHODS

We included all individuals who received analgesics reimbursed for chronic pain in Norway during 2010-9 (n=569 047). Among this population, we identified all individuals with drug overdoses as cause of death (cases). Extracting data from national registries on diagnoses, filled prescriptions, and socioeconomic variables, we used a nested case-control design to compare the cases with age- and sex-matched controls from the study population.

RESULTS

Overall, 623 (0.11%) individuals in the study population died of an overdose. Most, 66.8%, had overdosed accidentally, and 61.9% as a result of pharmaceutically available opioids. Compared with the controls (n=62 245), overdoses overall were associated strongly with substance use disorders (adjusted odds ratio 7.78 [95% confidence interval 6.20-9.77]), use of combinations of opioids, benzodiazepines and related drugs and gabapentinoids (4.60 [3.62-5.85]), previous poisoning with pharmaceuticals (2.78 [2.20-3.51]), and with living alone the last year of life (2.11 [1.75-2.54]). Intentional overdoses had a stronger association with previous poisonings with pharmaceuticals whereas accidental overdoses were strongly associated with substance use disorders.

CONCLUSIONS

This study shows the need for better identification of overdose and suicide risk in individuals treated for chronic pain. Extra caution is needed when treating complex comorbid disorders, especially with overdose risk-increasing medications.

Prevalence of use and impairment from drugs and alcohol among trauma patients: A national prospective observational study

BACKGROUND

Being under the influence of psychoactive substances increases the risk of involvement in and dying from a traumatic event. The study is a prospective population-based observational study that aims to determine the prevalence of use and likely impairment from psychoactive substances among patients with suspected severe traumatic injury.

METHOD

This study was conducted at 35 of 38 Norwegian trauma hospitals from 1 March 2019 to 29 February 2020. All trauma admissions for patients aged ≥ 16 years admitted via trauma team activation during the study period were eligible for inclusion. Blood samples collected on admission were analysed for alcohol, benzodiazepines, benzodiazepine-like hypnotics (Z-drugs), opioids, stimulants, and cannabis (tetrahydrocannabinol).

RESULTS

Of the 4878 trauma admissions included, psychoactive substances were detected in 1714 (35 %) and in 771 (45 %) of these, a combination of two or more psychoactive substances was detected. Regarding the level of impairment, 1373 (28 %) admissions revealed a concentration of one or more psychoactive substances indicating likely impairment, and 1052 (22 %) highly impairment. Alcohol was found in 1009 (21 %) admissions, benzodiazepines and Z-drugs in 613 (13 %), opioids in 467 (10 %), cannabis in 352 (7 %), and stimulants in 371 (8 %). Men aged 27-43 years and patients with violence-related trauma had the highest prevalence of psychoactive substance use with respectively 424 (50 %) and 275 (80 %) testing positive for one or more compounds.

CONCLUSION

The results revealed psychoactive substances in 35 % of trauma admissions, 80 % of which were likely impaired at the time of traumatic injury. A combination of several psychoactive substances was common, and younger males and patients with violence-related injuries were most often impaired. Injury prevention strategies should focus on high-risk groups and involve the prescription of controlled substances. We should consider toxicological screening in trauma admissions and incorporation of toxicological data into trauma registries.

Opioid prescriptions among Sami and non-Sami with chronic pain: The SAMINOR 2 Questionnaire Survey and the Norwegian Prescription Database

This study is the first to investigate the prevalence of filled opioid prescriptions among indigenous Sami people with self-reported chronic musculoskeletal pain (CMSP) and compare it with that of non-Sami living in the same area. Baseline data from the SAMINOR 2 Questionnaire Survey (2012) was linked prospectively to the Norwegian Prescription Database. Information on filled opioid prescriptions during 2012-2019 was collected for 4767 persons who reported CMSP in SAMINOR 2. Gender-stratified chi-square tests, two-sample t-tests, Kruskal - Wallis tests, and multinomial logistic regression was applied. Two out of three CMSP respondents received no or only one prescription of opioids during 2012-2019. In each year, 80% of women received no opioids, 7-10% received one prescription of ≤ 180 defined daily doses (DDD), 8-9% received in total ≤ 180 DDD in two or more prescriptions, and 2-3% received > 180 DDD of opioids. Among men, 81-83% received no opioids, 8-11% received one prescription with ≤ 180 DDD, 5-9% received ≤ 180 DDD in two or more prescriptions, and 1-2% received > 180 DDD of opioids in a single year. There were no overall ethnic differences, which indicates a similar prescription policy for opioids for Sami and non-Sami with CMSP.