Development of a coroner-based surveillance system for drug-related deaths in Los Angeles county

Identification of Non-Fatal Opioid Overdose Cases Using 9-1-1 Computer Assisted Dispatch and Prehospital Patient Clinical Record Variables

Background: The current epidemic of opioid overdoses in the United States necessitates a robust public health and clinical response. We described patterns of non-fatal opioid overdoses (NFOODs) in a small western region using data from the 9-1-1 Computer Assisted Dispatch (CAD) record and electronic Patient Clinical Records (ePCR) completed by EMS responders. We determined whether CAD and ePCR variables could identify NFOOD cases in 9-1-1 data for intervention and surveillance efforts. Methods: We conducted a retrospective analysis of 1 year of 9-1-1 emergency medical CAD and ePCR (including naloxone administration) data from the sole EMS provider in the response area. Cases were identified based on clinician review of the ePCR, and categorized as definitive NFOOD, probable NFOOD, or non-OOD. Sensitivity, specificity, positive and negative predictive values (PPV and NPV) of the most prevalent CAD and ePCR variables were calculated. We used a machine learning technique-Random-Forests (RF) modeling-to optimize our ability to accurately predict NFOOD cases within census blocks. Results: Of 37,960 9-1-1 calls, clinical review identified 158 NFOOD cases (0.4%), of which 123 (77.8%) were definitive and 35 (22.2%) were probable cases. Overall, 106 (67.1%) received naloxone from the EMS responder at the scene. As a predictor of NFOOD, naloxone administration by paramedics had 67.1% sensitivity, 99.6% specificity, 44% PPV, and 99.9% NPV. Using CAD variables alone achieved a sensitivity of 36.7% and specificity of 99.7%. Combining ePCR variables with CAD variables increased the diagnostic accuracy with the best RF model yielding 75.9% sensitivity, 99.9% specificity, 71.4% PPV, and 99.9% NPV. Conclusion: CAD problem type variables and naloxone administration, used alone or in combination, had sub-optimal predictive accuracy. However, a Random Forests modeling approach improved accuracy of identification, which could foster improved surveillance and intervention efforts. We identified the set of NFOODs that EMS encountered in a year and may be useful for future surveillance efforts.

Using medical examiner case narratives to improve opioid overdose surveillance

BACKGROUND

Current opioid overdose mortality surveillance methods do not capture the complexity of the overdose epidemic. Most rely on death certificates, which may underestimate both opioid analgesic and heroin deaths. Categorizing deaths using other characteristics from the death record including route of drug administration may provide useful information to design and evaluate overdose prevention interventions.

METHODS

We reviewed California Electronic Death Reporting System records and San Francisco Office of the Chief Medical Examiner (OCME) toxicology reports and investigative case narratives for all unintentional opioid overdose deaths in San Francisco County from 2006 to 2012. We chose this time period because it encompassed a period of evolution in local opioid use patterns and expansion of overdose prevention efforts. We created a classification system for heroin-related and injection-related opioid overdose deaths and compared demographic, death scene, and toxicology characteristics among these groups.

RESULTS

We identified 816 unintentional opioid overdose deaths. One hundred fifty-two (19%) were standard heroin deaths, as designated by the OCME or by the presence of 6-monoacetylmorphine. An "expanded" classification for heroin deaths incorporating information from toxicology reports and case narratives added 20 additional heroin deaths (13% increase), accounting for 21% of all opioid deaths. Two hundred five deaths (25%) were injection-related, 60% of which were attributed to heroin. A combined classification of expanded heroin and injection-related deaths accounted for 31% of opioid overdose deaths during this period.

CONCLUSIONS

Using additional sources of information to classify opioid overdose cases resulted in a modest increase in the count of heroin overdose deaths but identified a substantial number of non-heroin injection-related opioid analgesic deaths. Including the route of administration in the characterization of opioid overdose deaths can identify meaningful subgroups of opioid users to enhance surveillance efforts and inform targeted public health programming including overdose prevention programs.

Identifying cases of heroin toxicity where 6-acetylmorphine (6-AM) is not detected by toxicological analyses

PURPOSE

Heroin has a half-life of 2-6 min and is metabolized too quickly to be detected in autopsy samples. The presence of 6-acetylmophine (6-AM) in urine, blood, or other samples is convincing evidence of heroin use by a decedent, but 6-AM itself has a half-life of 6-25 min before it is hydrolyzed to morphine, so 6-AM may not be present in sufficient concentration to detect in postmortem samples. Codeine is often present in heroin preparations as an impurity and is not a metabolite of heroin. Studies report that a ratio of morphine to codeine greater than one indicates heroin use. We hypothesize that the ratio of morphine to codeine in our decedents abusing drugs intravenously will be no different in individuals with 6-AM present than in individuals where no 6-AM is detected, and we report our study of this hypothesis.

METHODS

All accidental deaths investigated by the Jefferson County Coroner/Medical Examiner Office from 2010 to 2013 with morphine detected in blood samples collected at autopsy were reviewed. Five deaths where trauma caused or contributed to death were excluded from the review. The presence or absence of 6-AM and the concentrations of morphine and codeine were recorded for each case. The ratio of morphine to codeine was calculated for all decedents. Any individual in whom no morphine or codeine was detected in a postmortem sample was excluded from further study. Absence or presence of drug paraphernalia or evidence of intravascular (IV) drug use was documented in each case to identify IV drug users. The proportion of the IV drug users with and without 6-AM present in a postmortem sample was compared to the M/C ratio for the individuals.

RESULTS

Of the 230 deaths included in the analysis, 103 IV drug users with quantifiable morphine and codeine in a postmortem sample were identified allowing for calculation of an M/C ratio. In these IV drug users, the M/C ratio was greater than 1 in 98 % of decedents. When controlling for the absence or presence of 6-AM there was no statistically significant difference in the proportion of IV drug users when compared to non IV drug users with an M/C ratio of greater than 1 (p = 1.000).

CONCLUSION

The M/C ratio in IV drug users, if greater than 1, is seen in deaths due to heroin toxicity where 6-AM is detected in a postmortem sample. This study provides evidence that a M/C ratio greater than one in an IV drug user is evidence of a death due to heroin toxicity even if 6-AM is not detected in the blood. Using the M/C ratio, in addition to scene and autopsy findings, provides sufficient evidence to show heroin is the source of the morphine and codeine. Listing heroin as a cause or contributing factor in deaths with evidence of IV drug abuse and where the M/C ratio exceeds 1 will improve identification of heroin fatalities, which will allow better allocation of resources for public health initiatives.

Drug-related deaths and the sales of needles through pharmacies

BACKGROUND

Providing needles to people who inject drugs is a well-proven public health response to the transmission of HIV and other blood borne viruses. Despite over a quarter of a century of research, new concerns about potential unintended negative consequences of needle distribution continue to emerge. Specifically, a claim was recently made that the introduction of pharmacy sales of needles was followed by an increase in overdoses in pharmacy parking lots. If true, this would have serious implications for the design of needle access programs, particularly those involving pharmacy sales of needles.

METHODS

We examine spatial relationships between drug-related deaths and pharmacies in Los Angeles County (population 9.8 million) before and after the 2007 enactment of a California law allowing pharmacy sales of needles without a prescription. Seven thousand and forty-nine drugs related deaths occurred in Los Angeles county from 2000 to 2009 inclusive. Four thousand two hundred and seventy-five of these deaths could be geocoded, and were found to be clustered at the census tract level.

RESULTS

We used three methods to examine spatial relationships between overdose death locations and pharmacy locations for two years on either side of the enactment of the pharmacy sales law, and found no statistically significant changes. Among the 711 geocodable deaths occurring in the two years following the change in law, no death was found to occur within 50m of a pharmacy which sold needles.

CONCLUSION

These results are consistent with prior studies which suggest pharmacy sales of needles improve access to needles without causing increased harms to the surrounding community.

Revisiting the role of the urban environment in substance use: the case of analgesic overdose fatalities

OBJECTIVES

We examined whether neighborhood social characteristics (income distribution and family fragmentation) and physical characteristics (clean sidewalks and dilapidated housing) were associated with the risk of fatalities caused by analgesic overdose.

METHODS

In a case-control study, we compared 447 unintentional analgesic opioid overdose fatalities (cases) with 3436 unintentional nonoverdose fatalities and 2530 heroin overdose fatalities (controls) occurring in 59 New York City neighborhoods between 2000 and 2006.

RESULTS

Analgesic overdose fatalities were less likely than nonoverdose unintentional fatalities to have occurred in higher-income neighborhoods (odds ratio [OR] = 0.82; 95% confidence interval [CI] = 0.70, 0.96) and more likely to have occurred in fragmented neighborhoods (OR = 1.35; 95% CI = 1.05, 1.72). They were more likely than heroin overdose fatalities to have occurred in higher-income (OR = 1.31; 95% CI = 1.12, 1.54) and less fragmented (OR = 0.71; 95% CI = 0.55, 0.92) neighborhoods.

CONCLUSIONS

Analgesic overdose fatalities exhibit spatial patterns that are distinct from those of heroin and nonoverdose unintentional fatalities. Whereas analgesic fatalities typically occur in lower-income, more fragmented neighborhoods than nonoverdose fatalities, they tend to occur in higher-income, less unequal, and less fragmented neighborhoods than heroin fatalities.

Prescription opioid mortality trends in New York City, 1990-2006: examining the emergence of an epidemic

BACKGROUND

The drug overdose mortality rate tripled between 1990 and 2006; prescription opioids have driven this epidemic. We examined the period 1990-2006 to inform our understanding of how the current prescription opioid overdose epidemic emerged in urban areas.

METHODS

We used data from the Office of the Chief Medical Examiner to examine changes in demographic and spatial patterns in overdose fatalities induced by prescription opioids (i.e., analgesics and methadone) in New York City (NYC) in 1990-2006, and what factors were associated with death from prescription opioids vs. heroin, historically the most prevalent form of opioid overdose in urban areas.

RESULTS

Analgesic-induced overdose fatalities were the only types of overdose fatalities to increase in 1990-2006 in NYC; the fatality rate increased sevenfold from 0.39 in 1990 to 2.7 per 100,000 persons in 2006. Whites and Latinos were the only racial/ethnic groups to exhibit an increase in overdose-related mortality. Relative to heroin overdose decedents, analgesic and methadone overdose decedents were more likely to be female and to concurrently use psychotherapeutic drugs, but less likely to concurrently use alcohol or cocaine. Analgesic overdose decedents were less likely to be Black or Hispanic, while methadone overdose decedents were more likely to be Black or Hispanic in contrast to heroin overdose decedents.

CONCLUSIONS

The distinct epidemiologic profiles exhibited by analgesic and methadone overdose fatalities highlight the need to define drug-specific public health prevention efforts.

Forensic Pathology and Epidemiology, Public Health and Population-Based Research

Forensic pathology can play a pivotal role in safeguarding public health. While medicolegal death investigation focuses on certifying cause and manner of individual deaths, taken in aggregate this information provides a powerful tool for epidemiologic research. The published literature provides numerous examples of the utility of forensic pathology in public health research, from describing trends in substance abuse deaths to reducing occupational fatalities and identifying unusual infectious disease deaths. Medical examiner and coroner (ME/C) offices contribute to public health research by participating in surveillance systems, including those for sudden unexplained infant deaths and violent deaths, and by alerting public health agencies to emerging threats. Accessing and utilizing ME/C data for epidemiologic research can be challenging, given the wide variation in types of jurisdictions and the availability of electronic data, but the rewards for researchers justify the endeavor. Mutually beneficial relationships can develop between epidemiologists and ME/Cs, improving both public health and medicolegal death investigation.