Personalised exhaled nitric oxygen fraction (FENO)-driven asthma management in primary care: a FENO subgroup analysis of the ACCURATE trial

Abstract

Background The aim of this study was to identify patients who benefit most from exhaled nitric oxide fraction (FENO)-driven asthma management in primary care, based on prespecified subgroups with different levels of FENO. Methods We used data from 179 adults with asthma from a 12-month primary care randomised controlled trial with 3-monthly assessments of FENO, asthma control, medication usage, costs of medication, severe asthma exacerbations and quality of life. In the original study, patients were randomised to either a symptom-driven treatment strategy (controlled asthma (Ca) strategy) or a FENO+symptom-driven strategy (FCa). In both groups, patients were categorised by their baseline level of FENO as low (50 ppb). At 12 months, we compared, for each prespecified FENO subgroup, asthma control, asthma-related quality of life, medication usage, and costs of medication between the Ca and FCa strategy. Results We found a difference between the Ca and FCa strategy for the mean dosage of beclomethasone strategy of 223 µg (95% CI 6–439), p=0.04) and for the total costs of asthma medication a mean reduction of US$159 (95% CI US$33–285), p=0.03) in patients with a low baseline FENO level. No differences were found for asthma control, severe asthma exacerbations and asthma-related quality of life in patients with a low baseline FENO level. Furthermore, in patients with intermediate or high level of FENO, no differences were found. Conclusions In primary care, FENO-driven asthma management is effective in patients with a low FENO level, for whom it is possible to down-titrate medication, while preserving asthma control and quality of life.