Limitations
Certain factors and limitations should be considered when interpreting the results of this study. Given that the study included only veterans, factors such as the demographic and clinical characteristics more commonly observed among these patients should be taken into account and may in turn limit the generalizability of these findings to nonveteran populations. Another major limitation is the small sample size; the study period and by extension, the number of patients able to be included in the present study were restricted by the availability of retrievable data from automated drug dispensing systems. Patients without documented response to naloxone were excluded from the study due to low clinical suspicion for opioid overdose, although the possibility that the dose administered was too low to produce a robust clinical response cannot be definitively ruled out. The lack of reliable methods to capture events and overdoses treated outside of the VA may have resulted in underestimations of the true occurrence of ORAEs following NFO. Information regarding naloxone administration outside VA facilities, such as in transport to the hospital, self-reported, or bystander administration, was similarly limited by lack of reliable methods for retrieving such data and absence of documentation in VA records. Although all interventions and outcomes reported in the present study occurred within 2 years following NFO, further conclusions pertaining to the relative timing of specific interventions and ORAEs cannot be made. Lastly, this study did not investigate the direct impact of opioid risk mitigation initiatives implemented by the VA in the years coinciding with the study period.
Future Directions
Despite these limitations, an important strength of this study is its ability to identify potential areas for targeted improvement and to guide further efforts relating to the prevention of opioid overdose and opioid-related mortality among veterans. Identification of individuals at high risk for opioid overdose and misuse is an imperative first step that allows for the implementation of downstream risk-mitigating interventions. Within the VA, several tools have been developed in recent years to provide clinicians with additional resources and support in this regard.6,15
No more than half of those diagnosed with mental health disorders and SUDs in the present study received outpatient follow-up care for these conditions within 6 months following NFO, which may suggest high rates of inadequate treatment. Given the strong association between mental health disorders, SUDs, and increased risk of overdose, increasing engagement with mental health and addiction treatment services may be paramount to preventing subsequent ORAEs, including repeat overdose.6-9,11
Naloxone kit dispensing represents another area for targeted improvement. Interventions may include clinician education and systematic changes, such as implementing protocols that boost the likelihood of high-risk individuals being provided with naloxone at the earliest opportunity. Bystander-administered naloxone programs can also be considered for increasing naloxone access and reducing opioid-related mortality.16
Finally, despite evidence supporting the benefit of MAT in OUD treatment and reducing all-cause and opioid-related mortality after NFO, the low rates of MAT observed in this study are consistent with previous reports that these medications remain underutilized.17 Screening for OUD, in conjunction with increasing access to and utilization of OUD treatment modalities, is an established and integral component of overdose prevention efforts. For VA clinicians, the Psychotropic Drug Safety Initiative (PDSI) dashboard can be used to identify patients diagnosed with OUD who are not yet on MAT.18 Initiatives to expand MAT access through the ED have the potential to provide life-saving interventions and bridge care in the interim until patients are able to become established with a long-term health care practitioner.19
Conclusions
This is the first study to describe HSU, medication interventions, and ORAEs among veterans who survive NFO. Studies have shown that veterans with a history of NFO are at increased risk of subsequent AEs and premature death.6,7,10,14 As such, NFOs represent crucial opportunities to identify high-risk individuals and ensure provision of adequate care. Recent data supports the development of a holistic, multimodal approach focused on adequate treatment of conditions that contribute to opioid-related risks, including mental health disorders, SUDs, pain diagnoses, and medical comorbidities.3,14 Interventions designed to improve access, engagement, and retention in such care therefore play a pivotal role in overdose prevention and reducing mortality.
Although existing risk mitigation initiatives have improved opioid prescribing and safety within the VA, the findings of this study suggest that there remains room for improvement, and the need for well-coordinated efforts to reduce risks associated with both prescribed and illicit opioid use cannot be overstated. Rates of overdose deaths not only remain high but are projected to continue increasing in coming years, despite advances in clinical practice aimed at reducing harms associated with opioid use. The present findings aim to help identify processes with the potential to reduce rates of overdose, death, and adverse sequelae in high-risk populations. However, future studies are warranted to expand on these findings and contribute to ongoing efforts in reducing opioid-related harms and overdose deaths. This study may provide critical insight to inform further investigations to guide such interventions and highlight tools that health care facilities even outside the VA can consider implementing.
Acknowledgments
The authors would like to thank Jonathan Lacro, PharmD, BCPP, for his guidance with this important clinical topic and navigating IRB submissions.