Comparing rates and characteristics of emergency department presentations related to pharmaceutical opioid poisoning in Australia: a study protocol for a retrospective observational study

A 3-year retrospective review of hospital admissions involving opioid toxicity in South Australia

INTRODUCTION

This article aims to characterise hospital admissions involving opioid toxicity across South Australia to guide future implementation and evaluation of risk mitigation strategies.

METHODS

International Classification of Diseases, 10th Edition codes (T40.0-T40.4) were used to identify admissions involving pre-hospital opioid toxicity in public hospitals across South Australia from 1 June 2017 to 30 August 2020. Demographic and episode of care data were extracted and summarised using descriptive statistics. Admission cost estimates were calculated using Independent Hospital Pricing Authority data.

RESULTS

A total of 2046 cases met the criteria for inclusion; over half (56%) were female and median age on admission was 44 years (interquartile range 27 years). Where opioid toxicity was the primary diagnosis, 70% of admissions did not specify the responsible opioid and 23% were related to heroin use. One-fifth of admissions occurred outside of metropolitan Adelaide. Individuals living in an area of relative socio-economic disadvantage were over-represented. Over half of admissions required a stay >24 h; 19% were admitted for ≥5 days, 22% required intensive care and ~10% required mechanical ventilation. The total estimated cost of admissions involving opioid toxicity in South Australia over the 3-year period was $18,230,546.50, equating to $5.6 million per annum.

DISCUSSIONS AND CONCLUSIONS

These findings highlight the significant personal, fiscal, and systemic impacts of opioid toxicity-related hospital admissions in South Australia and provide a baseline to evaluate the effectiveness of initiatives to reduce opioid-related harm, including real-time prescription monitoring and take-home naloxone supply.

A four-way patient search method for the retrospective identification of poisoning patients

When studying emergency department (ED) visits, electronic health record systems of hospitals provide a good basis for retrospective studies. However, many intoxication patients presenting to the ED, may not be identified retrospectively if only a single search method is applied. In this study, a new four-way combined patient search method was used to retrospectively identify intoxication patients presenting to the ED. The search included reason for admission to the ED, laboratory results related to intoxication diagnostics, ICD-10 codes, and a novel free word search (FWS) of patient records. After the automated search, the researcher read the medical records of potential substance abuse patients to form comprehensive profiles and remove irrelevant cases. The addition of a free word search identified 36% more substance abuse patients than the combination of the other three methods mentioned above. Patients identified by the FWS search alone were generally admitted to the ED for trauma or mental health problems and were often found to be heavily under the influence of alcohol and/or drugs. The main intoxicants were ethanol and benzodiazepines. The free word search was highly complementary to traditional patient search methods, highlighting the importance of the combined patient search method in retrospective data collection.

Improving injury surveillance data quality: a study based on hospitals contributing to the Victorian Emergency Minimum Dataset

OBJECTIVE

In this paper, we describe the design and baseline data of a study aimed at improving injury surveillance data quality of hospitals contributing to the Victorian Emergency Minimum Dataset (VEMD).

METHODS

The sequential study phases include a baseline analysis of data quality, direct engagement and communication with each of the emergency department (ED) hospital sites, collection of survey and interview data and ongoing monitoring.

RESULTS

In 2019/20, there were 371,683 injury-related ED presentations recorded in the VEMD. Percentage unspecified, the indicator of (poor) data quality, was lowest for 'body region' (2.7%) and 'injury type' (7.4%), and highest for 'activity when injured' (29.4%). In the latter, contributing hospitals ranged from 3.0-99.9% unspecified. The 'description of event' variable had a mean word count of 10; 16/38 hospitals had a narrative word count of <5.

CONCLUSIONS

Baseline hospital injury surveillance data vary vastly in data quality, leaving much room for improvement and justifying intervention as described. Implications for public health: Hospital engagement and feedback described in this study is expected to have a marked effect on data quality from 2021 onwards. This will ensure that Victorian injury surveillance data can fulfil their purpose to accurately inform injury prevention policy and practice.

Pharmaceutical opioid poisonings in Victoria, Australia: Rates and characteristics of a decade of emergency department presentations among nine pharmaceutical opioids

BACKGROUND AND AIMS

Pharmaceutical opioids are a significant contributor to the global 'opioid crisis', yet few studies have comprehensively distinguished between opioid types. We measured whether a range of common pharmaceutical opioids varied in their contribution to the rates and characteristics of harm in a population-wide indicator of non-fatal overdose.

DESIGN

Retrospective observational study of emergency department (ED) patient care records in the Victorian Emergency Minimum Data set (VEMD), July 2009 to June 2019.

SETTING

Victoria, Australia.

CASES

ED presentations for non-fatal overdose related to pharmaceutical opioid use (n = 5403), where the specific pharmaceutical opioid was documented.

MEASUREMENTS

We compared harms across the nine individual pharmaceutical opioids most commonly sold, and considered where multiple opioids contributed to the overdose. We calculated supply-adjusted rates of ED presentations using Poisson regression and used multinomial logistic regression to compare demographic and clinical characteristics of presentations among nine distinct pharmaceutical opioids and a 10th category where multiple opioids were documented for the presentation.

FINDINGS

There were wide differences, up to 27-fold, between supply-adjusted rates of overdose. When considering presentations with sole opioids, the highest supply-adjusted overdose rates [per 100 000 oral morphine equivalents (OME); 95% confidence interval (CI)] were for codeine (OME = 0.078, 95% CI = 0.073-0.08) and oxycodone (OME =0.029, 95% CI = 0.027-0.030) and the lowest were for tapentadol (OME = 0.004, 95% CI = 0.003-0.006) and fentanyl (OME = 0.003, 95% CI = 0.002-0.004). These rates appeared related to availability rather than opioid potency. Most (62%) poisonings involved females. Codeine, oxycodone and tramadol were associated with younger presentations (respectively, 59.5%, 41.7% and 49.8% of presentations were 12-34 years old), and intentional self-harm (respectively 65.2%, 50.6%, and 52.8% of presentations). Relative to morphine, fentanyl [ 0.32 relative risk ratio (RRR)] and methadone ( 0.58 RRR) presentations were less likely to be coded as self-harm. Relative to morphine-buprenorphine, codeine, oxycodone and tramadol presentations were significantly more likely to be associated with the less urgent triage categories (respectively 2.18, 1.80, 1.52, 1.65 RRR).

CONCLUSIONS

In Victoria, Australia, rates and characteristics of emergency department presentations for pharmaceutical opioids show distinct variations by opioid type.