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.

Five-Year Trajectories of Prescription Opioid Use.

Importance: There are known risks of using opioids for extended periods. However, less is known about the long-term trajectories of opioid use following initiation. Objective: To identify 5-year trajectories of prescription opioid use, and to examine the characteristics of each trajectory group. Design, Setting, and Participants: This population-based cohort study conducted in New South Wales, Australia, linked national pharmaceutical claims data to 10 national and state data sets to determine sociodemographic characteristics, clinical characteristics, drug use, and health services use. The cohort included adult residents (aged ≥18 years) of New South Wales who initiated a prescription opioid between July 1, 2003, and December 31, 2018. Statistical analyses were conducted from February to September 2022. Exposure: Dispensing of a prescription opioid, with no evidence of opioid dispensing in the preceding 365 days, identified from pharmaceutical claims data. Main Outcomes and Measures: The main outcome was the trajectories of monthly opioid use over 60 months from opioid initiation. Group-based trajectory modeling was used to classify these trajectories. Linked health care data sets were used to examine characteristics of individuals in different trajectory groups. Results: Among 3 474 490 individuals who initiated a prescription opioid (1 831 230 females [52.7%]; mean [SD] age, 49.7 [19.3] years), 5 trajectories of long-term opioid use were identified: very low use (75.4%), low use (16.6%), moderate decreasing to low use (2.6%), low increasing to moderate use (2.6%), and sustained use (2.8%). Compared with individuals in the very low use trajectory group, those in the sustained use trajectory group were older (age ≥65 years: 22.0% vs 58.4%); had more comorbidities, including cancer (4.1% vs 22.2%); had increased health services contact, including hospital admissions (36.9% vs 51.6%); had higher use of psychotropic (16.4% vs 42.4%) and other analgesic drugs (22.9% vs 47.3%) prior to opioid initiation, and were initiated on stronger opioids (20.0% vs 50.2%). Conclusions and relevance: Results of this cohort study suggest that most individuals commencing treatment with prescription opioids had relatively low and time-limited exposure to opioids over a 5-year period. The small proportion of individuals with sustained or increasing use was older with more comorbidities and use of psychotropic and other analgesic drugs, likely reflecting a higher prevalence of pain and treatment needs in these individuals.

The association between psychostimulant use in pregnancy and adverse maternal and neonatal outcomes: results from a distributed analysis in two similar jurisdictions.

BACKGROUND: Conflicting evidence suggests a possible association between use of prescribed psychostimulants during pregnancy and adverse perinatal outcomes. METHODS: We conducted population-based cohort studies including pregnancies conceived between April 2002 and March 2017 (Ontario, Canada; N = 554 272) and January 2003 to April 2011 [New South Wales (NSW), Australia; N = 139 229]. We evaluated the association between exposure to prescription amphetamine, methylphenidate, dextroamphetamine or lisdexamfetamine during pregnancy and pre-eclampsia, placental abruption, preterm birth, low birthweight, small for gestational age and neonatal intensive care unit admission. We used inverse probability of treatment weighting based on propensity scores to balance measured confounders between exposed and unexposed pregnancies. Additionally, we restricted the Ontario cohort to social security beneficiaries where supplementary confounder information was available. RESULTS: In Ontario and NSW respectively, 1360 (0.25%) and 146 (0.10%) pregnancies were exposed to psychostimulants. Crude analyses indicated associations between exposure and nearly all outcomes [OR range 1.15-2.16 (Ontario); 0.97-2.20 (NSW)]. Nearly all associations were attenuated after weighting. Pre-eclampsia was the exception: odds remained elevated in the weighted analysis of the Ontario cohort (OR 2.02, 95% CI 1.42-2.88), although some attenuation occurred in NSW (weighted OR 1.50, 95% CI 0.77-2.94) and upon restriction to social security beneficiaries (weighted OR 1.24, 95% CI 0.64-2.40), and confidence intervals were wide. CONCLUSIONS: We observed higher rates of outcomes among exposed pregnancies, but the attenuation of associations after adjustment and likelihood of residual confounding suggests psychostimulant exposure is not a major causal factor for most measured outcomes. Our findings for pre-eclampsia were inconclusive; exposed pregnancies may benefit from closer monitoring.

Cardiac assessment in Australian patients receiving (neo)adjuvant trastuzumab for HER2-positive early breast cancer: a population-based study.

PURPOSE: Cardiac function assessment is important for detecting and managing trastuzumab-associated cardiotoxicity. Our study estimates rates and predictors of cardiac assessment among patients receiving trastuzumab for HER2-positive early breast cancer (HER2+EBC) in Australia. METHODS: We conducted a retrospective cohort study of Australians initiating (neo)adjuvant trastuzumab for HER2+EBC between 1 January 2015 and 15 April 2019. We used administrative claims to determine the number of patients receiving guideline-recommended assessment, i.e. evidence of baseline cardiac assessment (between 120 days before and 30 days after trastuzumab initiation) and regular on-treatment cardiac assessments (at least every 120 days). We examined factors associated with baseline and regular on-treatment cardiac assessment. RESULTS: Our study includes 5621 patients (median age 56 years), of whom 4984 (88.7%) had a baseline cardiac function test. Among 4280 patients with at least 12 months of follow-up, 2702 (63.1%) had guideline-recommended cardiac assessment. Rates of guideline-recommended assessment increased with later year of diagnosis (60.9% in 2015 vs 68.3% in 2018, OR 1.34, 95% CI 1.06-1.69). Patients with higher baseline comorbidities and greater socioeconomic disadvantage were less likely to have guideline-recommended cardiac assessment. Cardiac assessment practices varied by State/Territory. There was no association between baseline cardiac risk or anthracycline use and the likelihood of receiving guideline-recommended cardiac assessment. CONCLUSION: The majority of patients receiving (neo)adjuvant trastuzumab had guideline-recommended baseline and on-treatment cardiac assessment. Variations in cardiac assessment predominantly related to system-level factors, such as year of diagnosis and geography, rather than individual patient factors.

Comparison of Prescribing Patterns Before and After Implementation of a National Policy to Reduce Inappropriate Alprazolam Prescribing in Australia.

Importance: Benzodiazepines have been a common target for policy interventions to curtail inappropriate use, with mixed results. To reduce alprazolam misuse, in February 2017, Australia delisted the 2-mg tablet strength from public subsidy, eliminated refills, and reduced the pack size from 50 tablets to 10 tablets. Objective: To describe changes in alprazolam dispensing, prescribing, and poisonings associated with the implementation of a new policy to reduce inappropriate prescription of alprazolam in Australia. Design, Setting, and Participants: This interrupted time series analysis and cross-sectional study included data from a 10% sample of Australian people who received publicly subsidized dispensing claims and prescribing approvals for alprazolam from January 1, 2015, to December 31, 2018, and all calls to a poison information service involving alprazolam from February 1, 2015, to October 31, 2018. Autoregressive error models were used to quantify changes over time and compare patterns of use before and after the intervention. Data analyses were conducted from November 2018 to May 2019. Exposure: Implementation of the policy change on February 1, 2017. Main Outcomes and Measures: Monthly trends in alprazolam prescribing approvals and dispensings, quarterly trends in telephone calls involving alprazolam to a poison information service, and patterns of prescribing and dispensing before and after the intervention. Results: From 2015 to 2018, there were 71 481 alprazolam dispensings to 6772 people. After the intervention, overall dispensing decreased by 51.2% (95% CI, 50.5%-51.9%) and prescribing approvals increased by 17.5% (95% CI, 13.0%-22.2%). Overall, the proportion of dispensing of packs of 51 to 100 tablets increased from 5776 of 24 282 dispensings (23.8%) to 4888 of 10 676 dispensings (45.8%) (risk difference [RD], 22.0% [95% CI, 19.4%-24.6%]) and dispensing of packs of more than 100 tablets increased from 1029 of 24 282 dispensings (4.2%) to 1774 of 10 676 dispensings (16.6%) (RD, 12.4% [95% CI, 10.6%-14.2%]). Among people receiving their first alprazolam prescription, initiation with packs of 10 tablets or fewer increased from 16 of 1127 people (1.4%) before the intervention to 139 of 589 people (23.6%) after the intervention (RD, 22.2% [95% CI, 18.7%-25.7%]). Alprazolam treatment initiation with packs of more than 50 tablets also increased from 63 of 1127 people (5.6%) before the intervention to 144 of 589 people (24.4%) after the intervention (RD, 18.9% [95% CI, 15.1%-22.6%]). During 1 year before the intervention, patients received a median (interquartile range [IQR]) total of 250 (50-600) tablets and median (IQR) total combined tablet strength of 188 (50-550) mg. During 1 year after the intervention, people were dispensed less alprazolam, with a median (IQR) total of 200 (50-500) tablets and median (IQR) total combined tablet strength of 120 (30-360) mg. There was little change in poisoning calls involving alprazolam. Conclusions and Relevance: This study found that after the policy intervention, subsidized alprazolam use decreased, but the increase in prescribing approvals placed additional burden on prescribers. Even after the intervention, most people who were dispensed alprazolam were still receiving treatment contrary to best-practice recommendations. Furthermore, the poison information center data suggested that people were still being dispensed the 2-mg tablet strength, presumably as nonsubsidized (ie, private) prescriptions.

The Australian Pharmaceutical Benefits Scheme data collection: a practical guide for researchers.

BACKGROUND: The Pharmaceutical Benefits Scheme (PBS) is Australia's national drug subsidy program. This paper provides a practical guide to researchers using PBS data to examine prescribed medicine use. FINDINGS: Excerpts of the PBS data collection are available in a variety of formats. We describe the core components of four publicly available extracts (the Australian Statistics on Medicines, PBS statistics online, section 85 extract, under co-payment extract). We also detail common analytical challenges and key issues regarding the interpretation of utilisation using the PBS collection and its various extracts. CONCLUSIONS: Research using routinely collected data is increasing internationally. PBS data are a valuable resource for Australian pharmacoepidemiological and pharmaceutical policy research. A detailed knowledge of the PBS, the nuances of data capture, and the extracts available for research purposes are necessary to ensure robust methodology, interpretation, and translation of study findings into policy and practice.