(B-133) Impact of Antibiotic Shortages on Antibiotic Utilisation in the Community: A Cross-National Comparison

Background: Antibiotic shortages are an increasing global problem negatively affecting treatment outcomes and antibiotic resistance. Despite this, limited research has been performed on assessing the impact of antibiotic shortages on antibiotic utilisation.

Objectives: To investigate the impact of antibiotic shortages on their utilisation in Australia and the Netherlands.

Methods: A cross-sectional study was conducted using reimbursement and regulatory data from January 2022 to December 2023. The number and duration of antibiotic shortages per product were determined for all oral antibiotics in Australia and the Netherlands. The clinical impact was assessed using national utilisation in Defined Daily Doses per 100,000 inhabitants. Changes in trends were analysed as Monthly Percent Changes (MPC) using Joinpoint regression.

Results: Shortages were reported for eighteen of the twenty-one (86%) oral antibiotics reimbursed in Australia and twenty of the thirty (67%) in the Netherlands. A total of 147 shortages were recorded in Australia and 135 in the Netherlands. Changes in utilisation coinciding with shortages were observed for eight antibiotics in Australia and six in the Netherlands. The impact of shortages in Australia was most pronounced for cefaclor (-20% MPC [CI -23.3; -14.5]) and roxithromycin (-26% MPC [CI -30.6;-15.1]), while in the Netherlands, cefaclor (-28% MPC [-50.6; -13.2]) and erythromycin (-18% MPC [-21.1; -16.8]) showed the largest declines, with significant Monthly Percent Changes (p < 0.05). Although relatively more antibiotics were affected in Australia, the clinical impact appeared more severe for certain shortages in the Netherlands. The number of available alternatives seemed to play a role in the clinical impact.

Conclusions: Antibiotic shortages were common in Australia and the Netherlands. The impact varied by antibiotic and country, with shortages coinciding with declines in utilisation. A multitude of factors seems to contribute to the impact of shortages.