Is higher population-level use of ICS/LABA combination associated with better asthma outcomes? Cross-sectional surveys of nationally representative populations in New Zealand and Australia

Helen K Reddel; Lutz Beckert; Angela Moran; Tristram Ingham; Rosario D Ampon; Matthew J Peters; Susan M Sawyer

doi:10.1111/resp.13123

Is higher population-level use of ICS/LABA combination associated with better asthma outcomes? Cross-sectional surveys of nationally representative populations in New Zealand and Australia

Respirology. 2017 Nov;22(8):1570-1578. doi: 10.1111/resp.13123. Epub 2017 Aug 9.

Authors

Helen K Reddel¹, Lutz Beckert^{2

3}, Angela Moran³, Tristram Ingham⁴, Rosario D Ampon¹, Matthew J Peters⁵, Susan M Sawyer⁶

Affiliations

¹ Woolcock Institute of Medical Research, University of Sydney, Glebe, NSW, Australia.
² Department of Medicine, University of Otago, Christchurch, New Zealand.
³ Respiratory Services, Canterbury District Health Board, Christchurch, New Zealand.
⁴ Department of Medicine, University of Otago, Wellington, New Zealand.
⁵ Department of Respiratory Medicine, Concord Hospital and Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia.
⁶ Department of Paediatrics, The University of Melbourne and Murdoch Childrens Research Institute, Royal Children's Hospital Centre for Adolescent Health, Melbourne, VIC, Australia.

PMID: 28791752
DOI: 10.1111/resp.13123

Abstract

Background and objective: New Zealand (NZ) and Australia (AU) have similarly high asthma prevalence; both have universal public health systems, but different criteria for subsidized medicines. We explored differences in asthma management and asthma-related outcomes between these countries.

Methods: A web-based survey was administered in AU (2012) and NZ (2013) to individuals aged ≥16 years with current asthma, drawn randomly from web-based panels, stratified by national population proportions. Symptom control was assessed with the Asthma Control Test (ACT). Healthcare utilization was assessed from reported urgent doctor/hospital visits in the previous year.

Results: NZ (n = 537) and Australian (n = 2686) participants had similar age and gender distribution. More NZ than Australian participants used inhaled corticosteroid (ICS)-containing medication (68.8% vs 60.9%; P = 0.006) but ICS/long-acting β₂ -agonist (LABA) constituted 44.4% of NZ and 81.5% of Australian total ICS use (P < 0.0001). Adherence was higher with ICS/LABA than ICS-alone (P < 0.0001), and higher in NZ than in AU (P < 0.0001). ACT scores were similar (P = 0.41), with symptoms well controlled in 58.6% and 54.4% participants, respectively. More NZ participants reported non-urgent asthma reviews (56.6% vs 50.4%; P = 0.009). Similar proportions had urgent asthma visits (27.9% and 28.6%, respectively, P = 0.75).

Conclusion: This comparison, which included the first nationally representative data for asthma control in NZ, showed that poorly controlled asthma is common in both NZ and AU, despite subsidized ICS-containing medications. The greater use of ICS-alone in NZ relative to ICS/LABA does not appear to have compromised population-level asthma outcomes, perhaps due to better adherence in NZ. Different ICS/LABA subsidy criteria and different patient copayments may also have contributed to these findings.

Keywords: antiasthmatic agents/therapeutic use; asthma; asthma/epidemiology; asthma/therapy; cross-sectional studies.

MeSH terms

Administration, Inhalation
Adolescent
Adrenergic beta-2 Receptor Agonists / administration & dosage*
Adult
Aged
Asthma / drug therapy*
Australia
Cross-Sectional Studies
Drug Therapy, Combination
Female
Glucocorticoids / administration & dosage*
Humans
Male
Middle Aged
New Zealand
Surveys and Questionnaires
Treatment Outcome
Young Adult

Substances

Adrenergic beta-2 Receptor Agonists
Glucocorticoids