{ "abstract": "Background: The updated New Zealand asthma guidelines in 2020, aligning with global asthma guideline recommendations, advocated for a fundamental shift from short-acting β2-agonist (SABA) reliever therapy to anti-inflammatory reliever (AIR) therapy (ICS-formoterol) in adults and adolescents. While aggregate population-level data indicate increased ICS-formoterol dispensings, patient-level changes in medication use remain unclear. We examined medication use patterns to assess early practice changes across the entire asthma population. Methods: We conducted a retrospective study using the New Zealand national linked health datasets. Patients aged ≥12 with asthma were identified from hospitalisation and/or dispensing data, and categorised by the complete set of inhaler classes dispensed in the three months preceding their final dispensing date within the baseline (July 2018–June 2020) and post-guideline (June 2020–June 2022) periods. Nine mutually exclusive categories were defined without applying any hierarchy between medications: SABA only; ICS, non-formoterol ICS-LABA, and ICS-formoterol, each with and without a concurrently dispensed SABA; other regimens; and no inhaled medication. Age subgroups (12–44 and ≥ 45 years) were examined. Children aged < 12 years throughout follow-up, who were outside the scope of the recommendation, served as a comparison cohort for difference-in-differences estimation. Findings: The cohort included 324,972 patients aged ≥12 years. At baseline, the SABA-only group was the most common (30.5%). Post-guideline, dispensing of the guideline-recommended regimen, ICS-formoterol without SABA, more than doubled from 10.9% to 23.8%, and any ICS-formoterol use rose from 18.9% to 34.5%. The proportion of patients dispensed any SABA fell from 74.1% to 60.8%. Of patients dispensed SABA only pre-guideline, 57.1% were dispensed SABA only again, while 17.6% changed to ICS-formoterol without SABA and 8.1% to ICS-formoterol with SABA. Continuity was high among patients on maintenance therapy (55.9% for ICS, 74.3% for non-formoterol ICS-LABA) and among those already dispensed ICS-formoterol (89.0%). Among post-guideline ICS-formoterol users, 31.1% were also dispensed a SABA, compared with 63.8% of non-formoterol ICS-LABA users and 70.2% of ICS users. Using children aged < 12 years as a comparison cohort, difference-in-differences estimates were +8.4 percentage points for ICS-formoterol without SABA and −8.3 percentage points for total SABA supply, but −0.2 percentage points for SABA monotherapy. Interpretation: The impact of the guideline change was substantial but selective. While the update facilitated transition for patients already receiving maintenance therapy, most patients on SABA-only regimens did not switch to the preferred AIR regimen. Further targeted implementation strategies beyond guideline publication are required to address this gap and ensure evidence-based care is consistently delivered. Funding: None.", "abstract_shown": true, "affiliations": [ "School of Pharmacy, The University of Auckland; Centre for Safe Medication Practice and Research, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong Special Administrative Region of China", "School of Pharmacy, The University of Auckland", "Woolcock Institute of Medical Research, Macquarie University, Sydney, Australia", "Alfred Hospital and Monash University, Melbourne, Australia", "School of Pharmacy, The University of Auckland; Corresponding author." ], "article_type": "research article", "arxiv": null, "author_total": 9, "authors": [ { "affs": [ 0 ], "name": "Franco Wing Tak Cheng" }, { "affs": [ 1 ], "name": "Jiayi Gong" }, { "affs": [ 1 ], "name": "Andrew Tomlin" }, { "affs": [ 1 ], "name": "William Harrison" }, { "affs": [ 1 ], "name": "Kebede Beyene" }, { "affs": [ 2 ], "name": "Helen K. Reddel" }, { "affs": [ 1 ], "name": "Jeff Harrison" }, { "affs": [ 3 ], "name": "Mark Hew" }, { "affs": [ 4 ], "name": "Amy Hai Yan Chan" } ], "bibtex": "https://research.draconitic.com/paper/cvb1e549majth.bib", "cited_by": 0, "doi": "10.1016/j.lanwpc.2026.102002", "fulltext_url": "http://www.sciencedirect.com/science/article/pii/S2666606526002063", "id": "cvb1e549majth", "issns": [ "2666-6065" ], "landing_url": "https://doi.org/10.1016/j.lanwpc.2026.102002", "language": "en", "licence": "CC-BY-NC", "licence_label": "CC BY-NC", "licence_source": "article", "licence_url": "https://creativecommons.org/licenses/by-nc/4.0/", "metadata_licence": null, "native_subjects": [ [ "heading", "Articles" ], [ "lcc", "RA1-1270" ], [ "openalex", "2737|Asthma and respiratory diseases" ] ], "openalex": "W7223176182", "pdf_url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13717112/pdf/?tool=EBI", "pmcid": "PMC13717112", "pmid": "42959359", "published": "2026-10-01", "publisher": "Elsevier", "ris": "https://research.draconitic.com/paper/cvb1e549majth.ris", "sources": [ { "first_seen": "2026-10-30T12:17:24Z", "native_id": "10add773c3664053b940ff19cfdc870d", "source": "doaj", "url": "https://doi.org/10.1016/j.lanwpc.2026.102002" }, { "first_seen": "2026-10-31T00:20:39Z", "native_id": "PMC:PMC13717112", "source": "europepmc", "url": "https://europepmc.org/article/PMC/PMC13717112" }, { "first_seen": "2026-10-31T12:21:46Z", "native_id": "MED:42959359", "source": "europepmc", "url": "https://europepmc.org/article/MED/42959359" }, { "first_seen": "2026-11-02T12:21:29Z", "native_id": "PMC13717112", "source": "pmc", "url": "https://doi.org/10.1016/j.lanwpc.2026.102002" } ], "subjects": [ { "field": "medicine", "origin": "openalex:2737|Asthma and respiratory diseases", "subfield": "physiology" } ], "title": "Implementation of the National Asthma Guidelines in New Zealand: a retrospective patient-level study of the change to anti-inflammatory reliever therapy in 324,972 patients", "title_text": "Implementation of the National Asthma Guidelines in New Zealand: a retrospective patient-level study of the change to anti-inflammatory reliever therapy in 324,972 patients", "type": "peer-reviewed", "updated_at": "2026-11-02T12:21:29Z", "url": "https://research.draconitic.com/paper/cvb1e549majth", "venue": "The Lancet Regional Health. Western Pacific", "versions": [] }