Using fractional exhaled nitric oxide (FeNO) to diagnose steroid‐responsive disease and guide asthma management in routine care

Abstract

BackgroundFractional exhaled nitric oxide (FeNO) is a surrogate marker of eosinophilic airway inflammation and good predictor of corticosteroid response.AimTo evaluate how FeNO is being used to guide primary care asthma management in the United Kingdom (UK) with a view to devising practical algorithms for the use of FeNO in the diagnosis of steroid-responsive disease and to guide on-going asthma management.MethodsEligible patients (n = 678) were those in the Optimum Patient Care Research Database (OPCRD) aged 4–80 years who, at an index date, had their first FeNO assessment via NIOX MINO® or Flex®. Eligible practices were those using FeNO measurement in at least ten patients during the study period. Patients were characterized over a one-year baseline period immediately before the index date. Outcomes were evaluated in the year immediately following index date for two patient cohorts: (i) those in whom FeNO measurement was being used to identify steroid-responsive disease and (ii) those in whom FeNO monitoring was being used to guide on-going asthma management. Outcomes for cohort (i) were incidence of new ICS initiation at, or within the one-month following, their first FeNO measurement, and ICS dose during the outcome year. Outcomes for cohort (ii) were adherence, change in adherence (from baseline) and ICS dose.OutcomesIn cohort (i) (n = 304) the higher the FeNO category, the higher the percentage of patients that initiated ICS at, or in the one month immediately following, their first FeNO measurement: 82%, 46% and 26% of patients with high, intermediate and low FeNO, respectively. In cohort (ii) (n = 374) high FeNO levels were associated with poorer baseline adherence (p = 0.005) but greater improvement in adherence in the outcome year (p = 0.017). Across both cohorts, patients with high FeNO levels were associated with significantly higher ICS dosing (p < 0.001).ConclusionsIn the UK, FeNO is being used in primary practice to guide ICS initiation and dosing decisions and to identify poor ICS adherence. Simple algorithms to guide clinicians in the practical use of FeNO could improved diagnostic accuracy and better tailored asthma regimens.

Comorbidity in severe asthma requiring systemic corticosteroid therapy: cross-sectional data from the Optimum Patient Care Research Database and the British Thoracic Difficult Asthma Registry

“…Data from the Optimum Patient Care Research Database (OPCRD)16 and British Thoracic Society (BTS) Difficult Asthma Registry17 (both described in the online supplementary data) were used to identify the cross-sectional prevalence of conditions due to systemic corticosteroid exposure in patients with SA. The most commonly reported adverse effects of OCS use are listed in online supplementary table E1 and the data were examined for these outcomes 2–15…”

Clinically relevant outcome measures for new therapies of asthma using pharmaceutical and biologic agents

“…F E NO is responsive to ICS and can reflect either treatment nonadherence or uncontrolled/ severe asthma. It is however considered an imperfect marker of long-term treatment needs [47]. Cut-off values may vary according to smoking/allergen exposure or in allergic, nonasthmatic individuals, but overall, the changes may be useful in drug interventions.…”

Challenges and Limitations of Testing Efficacy of Aerosol Device Delivery in Young Children

“…(40) Although it has been used for older children and adults for several decades, only recently has FENO been shown to be systematically reproducible in preschool and school-aged children. (41,42) With offline analysis, reference values have begun to be established for children as young as 12 months of age, whereas online analysis, typically used in older children and adults, requires a constant flow of 50 mL/sec.…”