Cohort profile: Using primary care data to understand Opioid Prescribing, Policy Impacts and Clinical Outcomes (OPPICO) in Victoria, Australia

Opioid characteristics and nonopioid interventions associated with successful opioid taper in patients with chronic noncancer pain

ABSTRACT

Current research indicates that tapering opioids may improve pain and function in patients with chronic noncancer pain. However, gaps in the literature remain regarding the choice of opioid and nonopioid interventions to support a successful taper. This study used an Australian primary care data set to identify a cohort of patients on long-term opioid therapy commencing opioid taper between January 2016 and September 2019. Using logistic regression analysis, we compared key clinical factors associated with differing taper outcomes. Of a total of 3371 patients who commenced taper, 1068 (31.7%) completed taper within 12 months. In the 3 months after commencement of taper, compared with those who did not complete taper, patients who successfully completed opioid taper were less likely to be prescribed buprenorphine (odds ratio [OR] 0.691; 95% CI: 0.530-0.901), fentanyl (OR, 0.429; 95% CI: 0.295-0.622), and long-acting (LA) opioids, including methadone (OR, 0.349; 95% CI: 0.157-0.774), oxycodone-naloxone (OR, 0.521; 95% CI: 0.407-0.669), and LA tapentadol (OR, 0.645; 95% CI: 0.461-0.902), but more likely to be prescribed codeine (OR, 1.308; 95% CI: 1.036-1.652). Compared with those who did not complete taper, patients who successfully tapered were less likely to be prescribed any formulations of oxycodone (short-acting [SA]: OR, 0.533; 95% CI: 0.422-0.672, LA: OR, 0.356; 95% CI: 0.240-0.530) and tramadol (SA: OR, 0.370; 95% CI: 0.218-0.628, LA: OR, 0.317; 95% CI: 0.234-0.428). The type of opioid prescribed in the months after commencement of taper seems to influence the taper outcomes. These findings may inform prospective studies on opioid taper.

Trajectories of prescription opioid tapering in patients with chronic non-cancer pain: a retrospective cohort study, 2015-2020

OBJECTIVE

To identify common opioid tapering trajectories among patients commencing opioid taper from long-term opioid therapy for chronic non-cancer pain and to examine patient-level characteristics associated with these different trajectories.

DESIGN

A retrospective cohort study.

SETTING

Australian primary care.

SUBJECTS

Patients prescribed opioid analgesics between 2015 and 2020.

METHODS

Group-based trajectory modeling and multinomial logistic regression analysis were conducted to determine tapering trajectories and to examine demographic and clinical factors associated with the different trajectories.

RESULTS

A total of 3369 patients commenced a taper from long-term opioid therapy. Six distinct opioid tapering trajectories were identified: low dose / completed taper (12.9%), medium dose / faster taper (12.2%), medium dose / gradual taper (6.5%), low dose / noncompleted taper (21.3%), medium dose / noncompleted taper (30.4%), and high dose / noncompleted taper (16.7%). A completed tapering trajectory from a high opioid dose was not identified. Among patients prescribed medium opioid doses, those who completed their taper were more likely to have higher geographically derived socioeconomic status (relative risk ratio [RRR], 1.067; 95% confidence interval [CI], 1.001-1.137) and less likely to have sleep disorders (RRR, 0.661; 95% CI, 0.463-0.945) than were those who didn't complete their taper. Patients who didn't complete their taper were more likely to be prescribed strong opioids (eg, morphine, oxycodone), regardless of whether they were tapered from low (RRR, 1.444; 95% CI, 1.138-1.831) or high (RRR, 1.344; 95% CI, 1.027-1.760) doses.

CONCLUSIONS

Those prescribed strong opioids and high doses appear to be less likely to complete tapering. Further studies are needed to evaluate the clinical outcomes associated with the identified trajectories.

Quality use of publicly subsidised tapentadol in Australia: a population-based analysis

BACKGROUND

Sustained-release (SR) tapentadol was listed on Australia's Pharmaceutical Benefits Scheme (PBS) in 2014 for chronic severe pain requiring long-term opioid treatment. Dispensings have increased since listing despite declining trends in other PBS-listed opioids. Preferential prescribing of SR opioids may increase the risk of dependence and accidental overdose, particularly when used to treat acute pain.

AIMS

To explore the quality use of publicly subsidised tapentadol in Australia.

METHODS

We examined annual initiation rates and patterns of use of tapentadol (SR) in the dispensing records of a 10% random sample of PBS-eligible Australians (2014-2021). We used national tapentadol sales data to assess the proportion of sales attributable to the PBS.

RESULTS

Tapentadol initiation increased from 2014, peaking at 7.5/1000 adult population in 2019 before declining to 5.3/1000 in 2021. We identified 63 766 new users between 2014 and 2020, of whom 92.8% discontinued in the first year following initiation, 58.0% had only a single dispensing and 34.3% had no other opioids dispensed in the 3 months before or after initiation. 27.8% of new users were dispensed tapentadol on the same day as potentially interacting medicines. There was a sustained drop in the proportion of sales attributable to the PBS from June 2020 onwards, from an average of 69.1%, to 63.9% of pack sales.

CONCLUSIONS

Patterns of use suggest tapentadol (SR) is generally used for short duration. Although most tapentadol sold in Australia is subsidised, there is evidence of a shift towards private sales.

Changes in opioid agonist treatment initiation among people prescribed opioids for pain following voluntary and mandatory prescription drug monitoring program implementation: A time series analysis

INTRODUCTION

Prescription drug monitoring programs (PDMP) are increasingly used to identify people prescribed high-dose opioids. However, little is known about whether PDMPs impact opioid agonist treatment (OAT) uptake, the gold standard for opioid use disorder. This study examined the impact of PDMP implementation on OAT initiation among people prescribed opioids, in Victoria, Australia.

METHODS

De-identified electronic records from all 464 Victorian general practices included in the POLAR database were used. OAT initiation was defined as a new OAT prescription between 1 April 2017 and 31 December 2020, with no OAT prescriptions in the year prior. Interrupted time series analyses were used to compare outcomes before (April 2017 to March 2019) and after (April 2019 to December 2020) PDMP implementation. Binary logistic regression was used to examine differences in patients' characteristics associated with OAT initiation prior to and after PDMP implementation.

RESULTS

In total, 1610 people initiated OAT, 946 before and 664 after PDMP implementation. No significant immediate (step) or longer-term (slope) changes in the rates of OAT initiation were identified following PDMP implementation, after adjusting for seasonality. A high opioid dose (>100 mg oral morphine equivalent) in the 6-months prior to OAT initiation was the only significant characteristic associated with reduced odds of OAT initiation post-PDMP implementation (odds ratio 0.29; 0.23-0.37).

DISCUSSION AND CONCLUSIONS

PDMP implementation did not have a significant impact on OAT initiation among people prescribed opioids. Findings suggest additional clinical initiatives that support OAT initiation are required to ensure PDMPs meet their intended target of reducing opioid-related harms.

Determining the Impact of Opioid Policy on Substance Use and Mental Health-Related Harms: Protocol for a Data Linkage Study

BACKGROUND

Increasing harms related to prescription opioids over the past decade have led to the introduction of a range of key national and state policy initiatives across Australia. These include introducing a mandatory real-time prescription drug-monitoring program in the state of Victoria from April 2020 and a series of changes to subsidies for opioids on the Pharmaceutical Benefit Scheme from June 2020. Together, these changes aim to influence opioid supply and reduce harms related to prescription opioids, yet few studies have specifically explored how these policies have influenced opioid prescribing and related harms in Australia.

OBJECTIVE

The aim of this study is to examine the impact of a range of opioid-related policies on hospital admissions and emergency department (ED) presentations in Victoria, Australia. In particular, the study aims to understand the effect of various opioid policies and opioid-prescribing changes on (1) the number and rates of ED presentations and hospital admissions attributed to substance use (ie, opioid and nonopioid related) or mental ill-health (eg, suicide, self-harm, anxiety, and depression), (2) the association between differing opioid dose trajectories and the likelihood of ED presentations and hospital admissions related to substance use and mental ill-health, and (3) whether changes in an individual's opioid prescribing change the risk related to ED presentations and hospital admissions related to substance use and mental ill-health.

METHODS

We will conduct a population-level linked data study. General practice health records obtained from the Population Level Analysis and Reporting platform are linked with person-level data from 3 large hospital networks in Victoria, Australia. Interrupted time series analysis will be used to examine the impact of opioid policies on a range of harms, including the rates of presentations related to substance use (opioid and nonopioid) and mental ill-health among the primary care cohort. Group-based trajectory modeling and a case-crossover design will be used to further explore the impact of changes in opioid dosage and other covariates on opioid and nonopioid poisonings and mental ill-health-related presentations at the patient level.

RESULTS

Given that this paper serves as a protocol, there are currently no results available. The deidentified primary health data were sourced from electronic medical records of approximately 4,717,000 patients from 542 consenting general practices over a 6-year period (2017-2022). The submission of results for publication is planned for early 2024.

CONCLUSIONS

This study will add to the limited evidence base to help understand the impact of opioid policies in Australia, including whether intended or unintended outcomes are occurring as a result.

TRIAL REGISTRATION

EU PAS Register EUPAS104005; https://www.encepp.eu/encepp/viewResource.htm?id=104006.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/51825.