Patterns of Asthma Medication Use in New Zealand After Publication of National Asthma Guidelines.

Abstract

In June 2020, the New Zealand (NZ) adolescent and adult asthma guidelines recommended budesonide/formoterol, taken as maintenance and/or reliever therapy, as the preferred therapeutic approach. To investigate whether these recommendations were associated with changes in clinical practice indicated by asthma medication use trends. NZ national dispensing data for inhaler medications from January 2010 to December 2021 were reviewed. Monthly "dispensings" of inhaled budesonide/formoterol, inhaled corticosteroid (ICS), other ICS/long-acting β2-agonists (LABA), and inhaled short-acting β2-agonists (SABA), for the 12+ age group, were displayed graphically with piecewise regression used to produce plots of rates by time with a July 1, 2020, break point. The number of dispensings in the last 6 months that data were available (July-December 2021) was compared with the corresponding period, July-December2019. Budesonide/formoterol dispensing increased markedly after July 1, 2020 (regression coefficient 41.1 inhalers dispensed/100,000 population per month [95% confidence interval (CI): 36.3-45.6, P < .0001]; 64.7% increase in the number of dispensings between July-December 2019 and July-December 2021), in contrast to "other ICS/LABA" (regression coefficient:-15.9 [95% CI:-22.2 to-9.6, P < .0001];-1.7% decrease) and SABA (regression coefficient:-14.7 [95% CI:-29.7 to 0.3, P= .055];-10.6% decrease), respectively. In NZ, a progressive increase in budesonide/formoterol dispensing, accompanied by a reduction in SABA and "other ICS/LABA" dispensing, occurred after publication of the 2020 NZ asthma guidelines. While acknowledging the limitations in the interpretation of temporal associations, these findings suggest that the transition to ICS/formoterol reliever-based therapy can be achieved if recommended and promoted as the preferred therapeutic approach in national guidelines.