Why comparative epidemiological indicators suggest that New Zealand is unlikely to experience a severe opioid epidemic

Persistent opioid use after hospital admission due to trauma: a population-based cohort study

ABSTRACT

Persistent opioid use (POU) is a common marker of harm related to opioid use after trauma. This study determined the incidence and risk factors for POU after hospitalisation due to trauma in New Zealand, among opioid-naïve patients. This was a population-based, retrospective cohort study, using linked data, involving all trauma patients of any age admitted to all NZ hospitals between 2007 and 2019. We included all patients who received opioids after discharge and were considered opioid naïve, defined as not having received opioids or not having a prior diagnosis of opioid-use disorder up to 365 days preceding the discharge date. The primary outcome was the incidence of POU defined as opioid use after discharge between 91 and 365 days. We used a multivariable logistic regression to identify independent risk factors for POU. A total of 177,200 patients were included in this study. Of these, 15.3% (n = 27,060) developed POU based on criteria used for the primary analysis, with sensitivity analyses showing POU incidence ranging from 14.3% to 0.8%. The opioid exposure risk factors associated with POU included switching between different opioids (adjusted odds ratio [aOR] 2.62; 95% confidence interval [CI] 2.51-2.73), prescribed multiple opioids (vs codeine, aOR 1.44; 95% CI 1.37-1.53), slow-release opioid formulations (aOR 1.32; 95% CI 1.26-1.39), and dispensed higher total doses of on the initial discharge prescription (aOR 1.26; 95% CI 1.20-1.33). Overall, 1 in 7 opioid-naïve patients who were exposed to opioids after trauma developed POU. Our findings highlight clinicians should be aware of these factors when continuing opioids on discharge.

Persistent Opioid Use After Hospital Admission From Surgery in New Zealand: A Population-Based Study

BACKGROUND

Persistent opioid use (POU) is common after surgery and is associated with an increased risk of mortality and morbidity. There have been no population-based studies exploring POU in opioid-naïve surgical patients in New Zealand (NZ). This study aimed to determine the incidence and risk factors for POU in opioid-naïve patients undergoing surgery in all NZ hospitals.

METHOD

We included all opioid-naïve patients who underwent surgery without a concomitant trauma diagnosis and received opioids after discharge from any NZ hospital between January 2007 and December 2019. Patients were considered opioid naïve if no opioids had been dispensed to them or if they did not have a prior diagnosis of an opioid-use disorder up to 365 days preceding the index date. The primary outcome was the incidence of POU, defined a priori as opioid use after discharge between 91 and 365 days. We used a multivariable logistic regression to identify risk factors for POU.

RESULTS

We identified 1789,407 patients undergoing surgery with no concomitant diagnosis of trauma; 377,144 (21.1%) were dispensed opioids and 260,726 patients were eligible and included in the analysis. Of those included in the final sample, 23,656 (9.1%; 95% confidence interval [CI], 9.0%-9.2%) developed POU. Risk factors related to how opioids were prescribed included: changing to different opioid(s) after discharge (adjusted odds ratio [aOR], 3.21; 95% CI, 3.04-3.38), receiving multiple opioids on discharge (aOR, 1.37; 95% CI, 1.29-1.45), and higher total oral morphine equivalents (>400 mg) (aOR, 1.23; 95% CI, 1.23-1.45). Conversely, patients who were coprescribed nonopioid analgesics on discharge had lower odds of POU (aOR, 0.91; 95% CI, 0.87-0.95). Only small differences were observed between different ethnicities. Other risk factors associated with increased risk of POU included undergoing neurosurgery (aOR, 2.02; 95% CI, 1.83-2.24), higher comorbidity burden (aOR, 1.90; 95% CI, 1.75-2.07), preoperative nonopioid analgesic use (aOR, 1.65; 95% CI, 1.60-1.71), smoking (aOR, 1.44; 95% CI, 1.35-1.54), and preoperative hypnotics use (aOR, 1.35; 95% CI, 1.28-1.42).

CONCLUSIONS

Approximately 1 in 11 opioid-naïve patients who were dispensed opioids on surgical discharge, developed POU. Potentially modifiable risk factors for POU, related to how opioids were prescribed included changing opioids after discharge, receiving multiple opioids, and higher total dose of opioids given on discharge. Clinicians should discuss the possibility of developing POU with patients before and after surgery and consider potentially modifiable risk factors for POU when prescribing analgesia on discharge after surgery.

Naloxone use by Aotearoa New Zealand emergency medical services, 2017-2021

OBJECTIVE

Emergency medical services (EMS) use of naloxone in the prehospital setting is indicated in patients who have significantly impaired breathing or level of consciousness when opioid intoxication is suspected. The present study characterised naloxone use in a nationwide sample of Aotearoa New Zealand road EMS patients to establish a baseline for surveillance of any changes in the future.

METHODS

A retrospective analysis of rates of patients with naloxone administrations was conducted using Hato Hone St John (2017-2021) and Wellington Free Ambulance (2018-2021) electronic patient report form datasets. Patient demographics, presenting complaints, naloxone dosing, and initial and last vital sign clinical observations were described.

RESULTS

There were 2018 patients with an equal proportion of males and females, and patient median age was 47 years. There were between 8.0 (in 2018) and 9.0 (in 2020) naloxone administrations per 100 000 population-years, or approximately one administration per day for the whole country of 5 million people. Poisoning by unknown agent(s) was the most common presenting complaint (61%). The median dose of naloxone per patient was 0.4 mg; 85% was administered intravenously. The median observed change in Glasgow Coma Scale score was +1, and respiratory rate increased by +2 breaths/min.

CONCLUSIONS

A national rate of EMS naloxone patients was established; measured clinical effects of naloxone were modest, suggesting many patients had reasons other than opioid toxicity contributing to their symptoms. Naloxone administration rates provide indirect surveillance information about suspected harmful opioid exposures but need to be interpreted with care.

Opioid prescribing patterns following common general surgery procedures in the Bay of Plenty, New Zealand

BACKGROUND

Global increases in opioid prescribing and misuse have prompted calls for closer regulation. Opioid prescription following surgery may lead to long term opioid use. A study was conducted evaluating opioid prescriptions on hospital discharge following common general surgery operations in the Bay of Plenty.

METHODS

Retrospective observational study over a two-year period in two regional New Zealand hospitals. Six hundred and eleven patients aged 18-64 years were assessed. Patients with complications, readmission, and a prescription of opioids in the preceding 3 months were excluded.

RESULTS

A total of 460 patients (165 Laparoscopic Cholecystectomy (LC), 200 Laparoscopic Appendicectomy (LA) and 95 Open Inguinal Hernia Repair (OIHR)) were included in analysis. Opioids were prescribed to 53% of LC, 55% of LA, and 60% of OIHR patients, with a mean of 75.8 Morphine Milligram Equivalents (MMEs), 75.3 MMEs, and 82.8 MMEs respectively. Seven percent of patients (18/254) received a second opioid prescription within 3 months, and of those only 1.6% (4/254) received a further prescription between 3 and 6 months from discharge. Opioid prescribing did not correlate with operation, ethnicity, age, length of stay, or gender, except for males receiving a more MMEs than females following LC (mean 102.0 MMEs versus 65.4 MMEs, P = 0.017).

CONCLUSION

This study shows a rate of opioid prescribing lower than the USA, and greater than seen in an Australian setting. Substantial amounts of opioids were prescribed following uncomplicated surgery, with significant variability. Improvements in training in post-operative opioid prescribing are needed. Fortunately, rates of ongoing opioid use were low.

The Burden of Metastatic Cancer-Induced Bone Pain: A Narrative Review

Bone pain is one of the most common forms of pain reported by cancer patients with metastatic disease. We conducted a review of oncology literature to further understand the epidemiology of and treatment approaches for metastatic cancer–induced bone pain and the effect of treatment of painful bone metastases on the patient’s quality of life. Two-thirds of patients with advanced, metastatic, or terminal cancer worldwide experience pain. Cancer pain due to bone metastases is the most common form of pain in patients with advanced disease and has been shown to significantly reduce patients’ quality of life. Treatment options for cancer pain due to bone metastases include nonsteroidal anti-inflammatory drugs, palliative radiation, bisphosphonates, denosumab, and opioids. Therapies including palliative radiation and opioids have strong evidence supporting their efficacy treating cancer pain due to bone metastases; other therapies, like bisphosphonates and denosumab, do not. There is sufficient evidence that patients who experience pain relief after radiation therapy have improved quality of life; however, a substantial proportion are nonresponders. For those still requiring pain management, even with available analgesics, many patients are undertreated for cancer pain due to bone metastases, indicating an unmet need. The studies in this review were not designed to determine why cancer pain due to bone metastases was undertreated. Studies specifically addressing cancer pain due to bone metastases, rather than general cancer pain, are limited. Additional research is needed to determine patient preferences and physician attitudes regarding choice of analgesic for moderate to severe cancer pain due to bone metastases.

What Are the Correlates of Global Variations in the Prevalence of Opioid Use Disorders? An Analysis of Data From the Global Burden of Disease Study, 2019

Introduction

The recent opioid crisis in North America has brought the problem of opioid use disorders (OUD) into clinical and public health focus, with experts warning that other countries or regions may be at future risk of experiencing such crises. The existing literature suggests that a wide range of social, cultural and economic factors may be associated with the onset, course and outcome of OUD in individuals. The current study uses data on the estimated prevalence of OUDs across 115 countries, obtained from the Global Burden of Disease Study, 2019, to examine the bivariate and multivariate associations between national prevalence of OUD and these factors.

Methods

Data on the estimated prevalence of OUDs was obtained via a database query from the Global Burden of Disease (GBD) Collaborative Network database for the year 2019. Recent (2018-2019) data on 10 relevant variables identified in the literature (gross national income, economic inequality, urbanization, social capital, religious affiliation and practice, unemployment, divorce, cultural individualism, and prevalence of depression) were obtained from the GBD, World Bank and Our World in Data databases. After transformation to a normal distribution, bivariate and univariate analyses were conducted to identify the significance and strength of the associations between these variables and the prevalence of OUD.

Results

Of the 10 variables studied, all variables except the divorce rate and religious affiliation were significantly correlated with the prevalence of OUD on bivariate analyses, though the strength of these associations was in the poor to fair range. On multivariate analysis, a significant association was observed only for the prevalence of depression, with trends towards a positive association for cultural individualism and unemployment, and a protective trend observed for religious practice.

Discussion

Though subject to certain limitations inherent in cross-sectional analyses, these results suggest that certain variables may be associated with a higher prevalence of OUD at the national level. Replication and refinement of these analyses may prove useful in identifying countries or regions at risk of a future opioid epidemic or crisis, which could facilitate the institution of preventive measures or early intervention strategies.