Michael B. Ward

Background: Fertility rates in Australia have been declining over recent decades, reaching a record low total fertility rate of 1.48 births per woman in 2024. Concurrently, vasectomy remains widely accessible and increasingly normalised as a permanent contraceptive option. Despite extensive commentary on falling birth rates, no contemporary Australian study has examined vasectomy rates relative to birth rates over time. We aimed to compare population level vasectomy and birth rates across Australian jurisdictions and age groups. Study design: Nationwide retrospective time-series study. Retrospective population-based study using Medicare Benefits Schedule item 37623 to identify vasectomy procedures performed between July 2015 and December 2024. Rates were calculated per 100,000 male population using quarterly Australian Bureau of Statistics (ABS) population estimates and summarised as rolling 12-month averages. Birth rates were derived using matched ABS data for women across equivalent age strata (18–24, 25–34, 35–44 years). Results: Vasectomy rates increased nationally from 32 per 100,000 in 2016 to 55 per 100,000 in 2023 before declining modestly in 2024. Birth rates declined from 5,200 to 3,800 per 100,000 over the same period. Trends were consistent across states and age groups, with the greatest vasectomy uptake in men aged 35–44 years. Conclusion: Australia is undergoing a demographic shift characterised by rising vasectomy uptake and declining fertility. We have observed changing secular trends in two related but distinct demographic indicators of reproductive intention. Ongoing monitoring of permanent and long-acting contraception is essential to understand evolving population dynamics and inform reproductive health policy. Short summary for non-experts: This nationwide study demonstrates that rising vasectomy uptake in Australia coincides with declining birth rates, particularly among men aged 35–44 years. Monitoring permanent contraceptive use alongside fertility trends may help clinicians and policymakers better understand changing reproductive intentions and inform future reproductive health planning. Short summary for non-experts: Australia’s birth rate has fallen to record lows, raising growing concerns about how changing reproductive choices may shape future society and healthcare needs. In this study, we found that vasectomy rates increased steadily across Australia between 2016 and 2024 while birth rates declined, particularly among adults aged 35-44 years. These findings suggest Australian men are increasingly choosing permanent contraception and highlight the need for ongoing monitoring of reproductive health trends to inform future policy and service planning.

Aim: To evaluate the utilization of Section 19A (S19A) medicines subsidized by the Pharmaceutical Benefits Scheme (PBS) in Australia and assess their role in maintaining access to medicines during shortages. Methods: Time series analysis was conducted on aggregate PBS dispensing data. Monthly dispensing volumes standardized to the Australian population, were examined for 15 medicines that had S19A listings between February 2016 and July 2024. Results: In the year following PBS listing, S19A medicines accounted for more than half of dispensing volume for 63% of medicines (12), demonstrating substantial uptake. However, dispensing volumes for each medicine overall were frequently lower than pre‐S19A PBS listing levels, suggesting that overall supply did not fully recover. Delays between PBS approval of S19A medicines and their first dispensing were observed for several products. These delays, alongside heterogeneous patterns of uptake across medicines, indicate that the S19A pathway does not uniformly restore access. For some medicines, limited awareness among prescribers or logistical barriers may have restricted timely use. Conclusion: The S19A pathway is an important regulatory mechanism to mitigate medicine shortages and maintain patient access to essential treatments. Despite substantial uptake for many medicines, delays and inconsistent recovery highlight opportunities to improve its effectiveness. Policy refinement should focus on reducing time to patient access and addressing implementation barriers to ensure continuity of care during supply disruptions.

Background Medicine shortages are an increasing threat to medicine safety and access. In Australia, a 7-month shortage of Coumadin 5-mg tablets (Dec 2022–Jul 2023) prompted Therapeutic Goods Administration (TGA) intervention via the Serious Scarcity Substitution Instrument (SSSI), allowing pharmacists to substitute 5-mg warfarin tablets with lower-strength tablets. Understanding the impact of this shortage on anticoagulant use and safety is essential for informing future regulatory responses. Aims The aim of this study was to assess the impact of the 2023 warfarin shortage in Australia on dispensing of warfarin and direct oral anticoagulants (DOACs), International Normalised Ratio (INR) testing, and adverse event reporting. Methods Monthly national dispensing data (January 2020–August 2024) were obtained from Pharmaceutical Benefits Scheme (PBS) Date of Supply data. INR pathology data were sourced from Services Australia. The TGA Medicines Shortages Database identified relevant shortage periods. Warfarin-related adverse events were extracted from the TGA Database of Adverse Event Notifications. Interrupted time series assessed changes in dispensing and INR testing trends over time. Results Warfarin dispensing declined by 1094 prescriptions per month prior to March 2023 (p < 0.0001). A short-term increase occurred in March 2023 (+ 8625 prescriptions; p = 0.0017) following implementation of the SSSI, although this was not sustained. At the warfarin strength level, dispensing rose for warfarin 1 mg and 2 mg but fell for 5 mg, with subsequent compensatory increases; 3 mg remained stable. DOAC dispensing increased steadily before March 2023 (+ 3771 prescriptions per month; p < 0.0001) but declined thereafter (− 3056 per month; p < 0.0001), most notably for rivaroxaban and dabigatran, while apixaban decreased non-significantly. INR testing briefly increased during the shortage and SSSI. A modest rise in haemorrhage-related adverse events was observed. Conclusion Warfarin supply was maintained during the 2023 shortage through strength-based substitution under the SSSI, with limited impact on DOAC dispensing.

Background and Objective Prior molecular modelling analysis identified several medicines as potential inhibitors of glutathione peroxidase 1 (GPx1) which may contribute to development or progression of chronic obstructive pulmonary disease (COPD). This study investigates 40 medicines (index medicines) for signals of COPD development or progression in a real-world dataset. Methods Sequence symmetry analysis (SSA) was conducted using a 10% extract of Australian Pharmaceutical Benefits Scheme (PBS) claims data between January 2013 and September 2019. Patients must have been initiated on an index medicine and a medicine for COPD development or progression within 12 months of each other. Sequence ratios were calculated as the number of patients who initiated an index medicine followed by a medicine for COPD development or progression divided by the number who initiated the index medicine second. An adjusted sequence ratio (aSR) was calculated which accounted for changes in prescribing trends. Adverse drug event signals (ADEs) were identified where the aSR lower 95% confidence interval (CI) was greater than 1. Results Twenty-one of 40 (53%) index medicines had at least one ADE signal of COPD development or progression. Signals of COPD development, as identified using initiation of tiotropium, were observed for atenolol (aSR 1.32, 95% CI 1.23–1.42) and naproxen (aSR 1.14, 95% CI 1.06–1.23). Several signals of COPD progression were observed, including initiation of fluticasone propionate/salmeterol following initiation of atenolol (aSR 1.44, 95% CI 1.30–1.60) and initiation of aclidinium/formoterol following initiation of naproxen (aSR 2.21, 95% CI 1.34–3.65). Conclusion ADE signals were generated for several potential GPx1 inhibitors; however, further validation of signals is required in large well-controlled observational studies.

Background: Chronic Obstructive Pulmonary Disease is characterised by declining lung function and a greater oxidative stress burden due to reduced activity of antioxidant enzymes such as Glutathione Peroxidase 1. Objectives: The extent to which drugs may contribute to this compromised activity is largely unknown. An integrative drug safety model explores inhibition of Glutathione Peroxidase 1 by drugs and their association with chronic obstructive pulmonary disease adverse drug events. Methods: In silico molecular modelling approaches were utilised to predict the interactions that drugs have within the active site of Glutathione Peroxidase 1 in both human and bovine models. Similarities of chemical features between approved drugs and the known inhibitor tiopronin were also investigated. Subsequently the Food and Drug Administration Adverse Event System was searched to uncover adverse drug event signals associated with chronic obstructive pulmonary disease. Results: Statistical and molecular modelling analyses confirmed that the use of several registered drugs, including acetylsalicylic acid and atenolol may be associated with inhibition of Glutathione Peroxidase 1 and chronic obstructive pulmonary disease. Conclusion: The integration of molecular modelling and pharmacoepidemological data has the potential to advance drug safety science. Ongoing review of medication use and further pharmacoepidemiological and biological analyses are warranted to ensure appropriate use is recommended. Graphical

Background: In elderly populations, paracetamol may be used regularly for conditions such as osteoarthritis. Paracetamol has been associated with respiratory disease through a proposed mechanism of glutathione depletion and oxidative stress. Given that chronic obstructive pulmonary disease (COPD) is frequently co-morbid with osteoarthritis, this study investigated whether the dose and timing of paracetamol exposure may induce COPD exacerbations. Methods: The study population was 3523 Australian Government Department of Veterans’ Affairs full entitlement holders who had existing COPD on 1 January 2011, who were dispensed at least one prescription of paracetamol between 1 January 2011 and 30 September 2015, and had no paracetamol dispensed in the 6 months prior to 1 January 2011. The outcome was time to first hospitalisation for COPD exacerbation after initiation of paracetamol. A weighted cumulative exposure approach was used. Results: The association between paracetamol exposure and COPD exacerbation was protective or harmful depending on the dose, duration, and recency of exposure. Compared to non-use, current use at the maximum dose of 4 g daily for 7 days was associated with a lower risk (HR = 0.78, 95% CI = 0.67–0.92) and a higher risk after 30 days (HR = 1.27, 95% CI = 1.06–1.52). Risk declined to baseline after 2 months. For past use, there was a short-term increase in risk on discontinuation depending of dose, duration and time since stopping. Conclusions: Patients and doctors should be aware of the possible risk of COPD exacerbation with higher dose paracetamol 1 to 6 weeks after initiation or discontinuation, but no increased risk after 2 months.

What is Known and Objective Proton pump inhibitors (PPIs), used to treat and prevent gastro-oesophageal conditions, are well-tolerated but have been associated with risk including pneumonia. The extent to which initiation of PPIs can contribute to other respiratory conditions such as chronic obstructive pulmonary disease (COPD) is largely unknown. Methods A sequence symmetry analysis (SSA) approach was applied to the Australian Department of Human Services, Pharmaceutical Benefits Scheme 10% extract. Participants were aged 45 years and older and were dispensed PPIs (ATC Codes A02BC01, A02BC02, A02BC03, A02BC04 and A02BC05) and long-acting bronchodilators (LABDs) for COPD (ATC Codes R03BB04 (PBS Item Code 10509D and 08626B), R03BB05, R03BB06, R03BB07 and R03AC18 (PBS Item Code 05137J and 05134F)) between 2013 and 2019. The analysis included patients initiated on an LABD within 12 months before or after their first prescription of a PPI. The crude sequence ratio (cSR) was calculated as the number of patients prescribed their first LABD after starting a PPI divided by the number of patients prescribed their first LABD before starting a PPI. Calculation of the adjusted sequence ratio (aSR) accounted for prescribing trends over time in initiation of each of the medicines. A signal was identified where the aSR lower 95% confidence interval (CI) was greater than one. Results and Discussion Initiation of omeprazole was associated with a 29% increased risk of initiating a LABD (ASR = 1.29 95% CI 1.22–1.36). Initiation of esomeprazole, rabeprazole, pantoprazole or lansoprazole was associated with 25%, 15%, 8% and 8% increased risk, respectively. What is New and Conclusion There is an established association between gastro-oesophageal reflux disease and COPD which has been confirmed by implementation of a sequence symmetry-based approach which demonstrated that PPI initiation is potentially associated with progression or exacerbation of COPD. The impact PPI use has directly on this association requires further investigation.