Longitudinal trends in community antibiotic dispensing: a surveillance study of Aotearoa New Zealand from 2010 to 2019

We aimed to investigate community systemic antibiotic dispensing in New Zealand across 2010-2019. This longitudinal study utilised dispensing data from the National Pharmaceutical Collection and population data from the Health New Zealand - Te Whatu Ora populations web tool. Dispensing rates were measured as the number of defined daily doses/1,000 inhabitants per day (DIDs) and courses dispensed/1,000 inhabitants/year. Dispensing data were stratified by antibiotic group, AWaRe (Access, Watch, Reserve) categories, district health board (DHB) region and patient characteristics. Between January 1 2010 and December 31 2019, community systemic antibiotic dispensing in New Zealand declined, with courses dispensed dropping from 930 to 782 (average annual change [AAC] -1.9%) and DID from 20.9 to 19.6 (AAC -0.75%). Watch antibiotics decreased by 8% in courses dispensed/1,000 inhabitants/year, with quinolones showing the largest proportional reduction (-37 courses dispensed/1,000 inhabitants/year; AAC -13.4%). Conversely, first-generation cephalosporins increased significantly (+45 courses dispensed/1,000 inhabitants/year; AAC +56%), primarily due to cefalexin. Ethnic differences persisted, with Pacific people consistently exhibiting the highest dispensing rates. Most DHB regions experienced an overall decline in dispensing during this period. The study identified encouraging trends in antibiotic dispensing, reflecting New Zealand's antimicrobial stewardship initiatives, but also highlighted the rise in cefalexin and ongoing variations that require further investigation.