Impact of an opioid risk reduction initiative on motor vehicle crash risk among chronic opioid therapy patients

Effectiveness of road safety interventions: An evidence and gap map

Background

Road Traffic injuries (RTI) are among the top ten leading causes of death in the world resulting in 1.35 million deaths every year, about 93% of which occur in low- and middle-income countries (LMICs). Despite several global resolutions to reduce traffic injuries, they have continued to grow in many countries. Many high-income countries have successfully reduced RTI by using a public health approach and implementing evidence-based interventions. As many LMICs develop their highway infrastructure, adopting a similar scientific approach towards road safety is crucial. The evidence also needs to be evaluated to assess external validity because measures that have worked in high-income countries may not translate equally well to other contexts. An evidence gap map for RTI is the first step towards understanding what evidence is available, from where, and the key gaps in knowledge.

Objectives

The objective of this evidence gap map (EGM) is to identify existing evidence from all effectiveness studies and systematic reviews related to road safety interventions. In addition, the EGM identifies gaps in evidence where new primary studies and systematic reviews could add value. This will help direct future research and discussions based on systematic evidence towards the approaches and interventions which are most effective in the road safety sector. This could enable the generation of evidence for informing policy at global, regional or national levels.

Search Methods

The EGM includes systematic reviews and impact evaluations assessing the effect of interventions for RTI reported in academic databases, organization websites, and grey literature sources. The studies were searched up to December 2019.

Selection Criteria

The interventions were divided into five broad categories: (a) human factors (e.g., enforcement or road user education), (b) road design, infrastructure and traffic control, (c) legal and institutional framework, (d) post-crash pre-hospital care, and (e) vehicle factors (except car design for occupant protection) and protective devices. Included studies reported two primary outcomes: fatal crashes and non-fatal injury crashes; and four intermediate outcomes: change in use of seat belts, change in use of helmets, change in speed, and change in alcohol/drug use. Studies were excluded if they did not report injury or fatality as one of the outcomes.

Data Collection and Analysis

The EGM is presented in the form of a matrix with two primary dimensions: interventions (rows) and outcomes (columns). Additional dimensions are country income groups, region, quality level for systematic reviews, type of study design used (e.g., case-control), type of road user studied (e.g., pedestrian, cyclists), age groups, and road type. The EGM is available online where the matrix of interventions and outcomes can be filtered by one or more dimensions. The webpage includes a bibliography of the selected studies and titles and abstracts available for preview. Quality appraisal for systematic reviews was conducted using a critical appraisal tool for systematic reviews, AMSTAR 2.

Main Results

The EGM identified 1859 studies of which 322 were systematic reviews, 7 were protocol studies and 1530 were impact evaluations. Some studies included more than one intervention, outcome, study method, or study region. The studies were distributed among intervention categories as: human factors (n = 771), road design, infrastructure and traffic control (n = 661), legal and institutional framework (n = 424), post-crash pre-hospital care (n = 118) and vehicle factors and protective devices (n = 111). Fatal crashes as outcomes were reported in 1414 records and non-fatal injury crashes in 1252 records. Among the four intermediate outcomes, speed was most commonly reported (n = 298) followed by alcohol (n = 206), use of seatbelts (n = 167), and use of helmets (n = 66). Ninety-six percent of the studies were reported from high-income countries (HIC), 4.5% from upper-middle-income countries, and only 1.4% from lower-middle and low-income countries. There were 25 systematic reviews of high quality, 4 of moderate quality, and 293 of low quality.

Authors' Conclusions

The EGM shows that the distribution of available road safety evidence is skewed across the world. A vast majority of the literature is from HICs. In contrast, only a small fraction of the literature reports on the many LMICs that are fast expanding their road infrastructure, experiencing rapid changes in traffic patterns, and witnessing growth in road injuries. This bias in literature explains why many interventions that are of high importance in the context of LMICs remain poorly studied. Besides, many interventions that have been tested only in HICs may not work equally effectively in LMICs. Another important finding was that a large majority of systematic reviews are of low quality. The scarcity of evidence on many important interventions and lack of good quality evidence-synthesis have significant implications for future road safety research and practice in LMICs. The EGM presented here will help identify priority areas for researchers, while directing practitioners and policy makers towards proven interventions.

Opioids and the Risk of Motor Vehicle Collision: A Systematic Review

Background: Opioid analgesics are among the most commonly prescribed medications, but questions remain regarding their impact on the day-to-day functioning of patients including driving. We set out to perform a systematic review on the risk of motor vehicle collision (MVC) associated with prescription opioid exposure. Method: We searched Medline, PubMed, EMBASE, Scopus, and TRID from January 1990 to August 31, 2021 for primary studies assessing prescribed opioid use and MVCs. Results: We identified 14 observational studies that met inclusion criteria. Among those, 8 studies found an increased risk of MVC among those participants who had a concomitant opioid prescription at the time of the MVC and 3 found no significant increase of culpability of fatal MVC. The 3 studies that evaluated the presence of a dose-response relationship between the dose of opioids taken and the effects on MVC risk reported the existence of a dose-response relationship. Due to the heterogeneity of the different studies, a quantitative meta-analysis to sum evidence was deemed unfeasible. Our review supports increasing evidence on the association between motor vehicle collisions and prescribed opioids. This research would guide policies regarding driving legislation worldwide. Conclusion: Our review indicates that opioid prescriptions are likely associated with an increased risk of MVCs. Further studies are warranted to strengthen this finding, and investigate additional factors such as individual opioid medications, opioid doses and dose adjustments, and opioid tolerance for their effect on MVC risk.

Obstructive sleep apnea and risk of motor vehicle accident

OBJECTIVE

To evaluate the association between obstructive sleep apnea (OSA) and risk of motor vehicle accident (MVA).

METHODS

We conducted a cohort study at Kaiser Permanente Washington using electronic health plan data and linked Washington State Department of Transportation MVA records. We included persons 18-79 years of age during 2005-2014. OSA was ascertained via diagnosis codes. The primary outcome, first MVA during cohort follow-up, was ascertained from state MVA records. Risk factors for MVAs, including medical conditions and medication use, were ascertained from health plan data. Multivariable Cox proportional hazards models were used to estimate the adjusted hazard ratio (HR) and 95% confidence interval (CI) for the association between OSA and study outcomes.

RESULTS

Among the 879,547 eligible persons, the unadjusted rate of MVA in those with and without OSA was 238 and 229 per 10,000 person-years, respectively. A diagnosis of OSA was associated with a 17% increased risk of MVA (adjusted HR = 1.17; 95% CI: 1.13 to 1.20).

CONCLUSION

In this large population-based study, a diagnosis of OSA was associated with a modestly increased risk of MVA.

Prescription opioid use among drivers in British Columbia, 1997–2016

Background

Opioids increase the risk of traffic crash by limiting coordination, slowing reflexes, impairing concentration and producing drowsiness. The epidemiology of prescription opioid use among drivers remains uncertain. We aimed to examine population-based trends and geographical variation in drivers’ prescription opioid consumption.

Methods

We linked 20 years of province-wide driving records to comprehensive population-based prescription data for all drivers in British Columbia (Canada). We calculated age- and sex-standardised rates of prescription opioid consumption. We assessed temporal trends using segmented linear regression and examined regional variation in prescription opioid use using maps and graphical techniques.

Results

A total of 46 million opioid prescriptions were filled by 3.0 million licensed drivers between 1997 and 2016. In 2016 alone, 14.7% of all drivers filled at least one opioid prescription. Prescription opioid use increased from 238 morphine milligram equivalents per driver year (MMEs/DY) in 1997 to a peak of 834 MMEs/DY in 2011. Increases in MMEs/DY were greatest for higher potency and long-acting prescription opioids. The interquartile range of prescription opioid dispensation by geographical region increased from 97 (Q1=220, Q3=317) to 416 (Q1=591, Q3=1007) MMEs/DY over the study interval.

Implications

Patterns of prescription opioid consumption among drivers demonstrate substantial temporal and geographical variation, suggesting they may be modified by clinical and policy interventions. Interventions to curtail use of potentially impairing prescription medications might prevent impaired driving.

Strengths and weaknesses of existing data sources to support research to address the opioids crisis

Better opioid prescribing practices, promoting effective opioid use disorder treatment, improving naloxone access, and enhancing public health surveillance are strategies central to reducing opioid-related morbidity and mortality. Successfully advancing and evaluating these strategies requires leveraging and linking existing secondary data sources. We conducted a scoping study in Fall 2017 at RAND, including a literature search (updated in December 2018) complemented by semi-structured interviews with policymakers and researchers, to identify data sources and linking strategies commonly used in opioid studies, describe data source strengths and limitations, and highlight opportunities to use data to address high-priority public health research questions. We identified 306 articles, published between 2005 and 2018, that conducted secondary analyses of existing data to examine one or more public health strategies. Multiple secondary data sources, available at national, state, and local levels, support such research, with substantial breadth in data availability, data contents, and the data's ability to support multi-level analyses over time. Interviewees identified opportunities to expand existing capabilities through systematic enhancements, including greater support to states for creating and facilitating data use, as well as key data challenges, such as data availability lags and difficulties matching individual-level data over time or across datasets. Multiple secondary data sources exist that can be used to examine the impact of public health approaches to addressing the opioid crisis. Greater data access, improved usability for research purposes, and data element standardization can enhance their value, as can improved data availability timeliness and better data comparability across jurisdictions.

Impact of initiatives to reduce prescription opioid risks on medically attended injuries in people using chronic opioid therapy

PURPOSE

The purpose of the study is to determine whether initiatives to improve the safety of opioid prescribing decreased injuries in people using chronic opioid therapy (COT).

METHODS

We conducted an interrupted time series analysis using data from Group Health (GH), an integrated health care delivery system in the United States. In 2007, GH implemented initiatives which substantially reduced daily opioid dose and increased patient monitoring. Among GH members age 18 or older receiving COT between 2006 and 2014, we compared injury rates for patients in GH's integrated group practice (IGP; exposed to the initiatives) vs patients cared for by contracted providers (not exposed). Injuries were identified using a validated algorithm. We calculated injury incidence during the baseline (preintervention) period from 2006 to 2007; the dose reduction period, 2008 to 2010; and the risk stratification and monitoring period, 2010 to 2014. Using modified Poisson regression, we estimated adjusted relative risks (RRs) representing the relative change per year in injury rates.

RESULTS

Among 21 853 people receiving COT in the IGP and 8260 in contracted care, there were 2679 injuries during follow-up. The baseline injury rate was 1.0% per calendar quarter in the IGP and 0.9% in contracted care. Risk reduction initiatives did not decrease injury rates: Within the IGP, the RR in the dose reduction period was 1.01 (95% CI, 0.95-1.07) and in the risk stratification and monitoring period, 0.99 (95% CI, 0.95-1.04). Injury trends did not differ between the two care settings.

CONCLUSIONS

Risk reduction initiatives did not decrease injuries in people using COT.

Diagnosed dementia and the risk of motor vehicle crash among older drivers

Older adults are an active and growing segment of drivers in the United States. We compared the risk of motor vehicle crash among older licensed drivers diagnosed with dementia to crash risk among older licensed drivers without diagnosis of dementia. This retrospective cohort study used data from Group Health (GH), a Washington State health maintenance organization. Research participants were members of GH, aged 65-79 during the study who lived in Washington State from 1999-2009. Participant health records were linked with police-reported crash and licensure records. We estimated the risk of crash for older drivers diagnosed with dementia compared to older drivers without diagnosis of dementia using a Cox proportional hazards model with robust standard errors, accounting for recurrent events (crashes). Multivariable models were adjusted for age, sex, history of alcohol abuse or depression, comorbidities, and medications. There were 29,730 eligible individuals with an active driving license. Approximately 6% were diagnosed with dementia before or during the study. The police-reported crash rate was 14.7 per 1000 driver-years. The adjusted hazard ratio of crash among older drivers with diagnosed dementia was 0.56 (95% CI 0.33, 0.95) compared to those without diagnosed dementia. On-road and simulator-based research showed older adults with dementia demonstrated impaired driving skill and capabilities. The observed lower crash risk in our study may result from protective steps to limit driving among older adults diagnosed with dementia. Future research should examine driving risk reduction strategies at the time of dementia diagnosis and their impact on reducing crash risk.