Fractional exhaled nitric oxide was not associated with the future risk of exacerbations in Chinese asthmatics: a non-interventional 1-year real-world study

Newly diagnosed asthma in China: initial severity and changes over a 1-year management period

Background

There are no large sample, epidemiological data describing initial asthma severity and change. We used a large health care database to examine asthma severity at initial diagnosis, and the changes in severity over the first year of management.

Methods

The clinical data of patients diagnosed with asthma for the first time were collated from the SuValue electronic medical database. The following inclusion criteria were applied: (I) patients who were 14 years or older at the time of first diagnosis; (II) initial diagnosis occurred between Jan 2001 and Mar 2019; (III) patients were followed up for at least 12 months; (IV) patients had follow-up visits every 3 months. Disease severity at diagnosis and at each follow-up visit, medications prescribed were collated and analyzed.

Results

A total of 7,654 adult patients with newly diagnosed asthma from tertiary hospitals (26.38%) and secondary hospitals (73.62%), who were followed up for at least 12 months, were included in this retrospective analysis. Approximately 54% of patients were females and the largest age group was over 60 years old (37.66%). Nearly 16% of patients were moderate to severe asthma initially. The proportions of patients with moderate and severe asthma decreased during the first 6 months, and remained stable thereafter. At the end of the 1-year follow-up period, 2.7% of patients had severe asthma. Patients with mild asthma tended to continue to have mild asthma in the following 3 months (>76.19%). However, of the patients with mild or moderate asthma at 3 months, 92.85% and 75.1%, respectively, experienced maintenance and reduction in severity and had mild asthma by 12 months. 1.26% and 3.15% of patients with mild or moderate asthma, respectively, progressed to severe asthma by 12 months.

Conclusions

Patients with mild asthma did not progress but rather, remained stable with mild asthma over the year. A proportion of patients diagnosed with moderate and severe asthma remained stable over a 1-year period. Further studies should be conducted to examine the clinical features of newly diagnosed patients with severe asthma without reduction in severity in order to facilitate intensive treatment and reduce the disease burden for these patients.

Assessment of adherence to corticosteroids in asthma by drug monitoring or fractional exhaled nitric oxide: A literature review

Background

Although the efficacy of corticosteroid treatment in controlling asthma is widely accepted, its effectiveness is undermined by poor adherence. However, the optimal method for measuring adherence to asthma therapy remains unclear.

Objective

To perform a review of the literature reporting biological, objective methods for assessing adherence to inhaled or oral corticosteroids in asthma; we included studies reporting direct measurement of exogenous corticosteroids in blood, or the effect of adherence on exhaled nitric oxide.

Design

We searched three databases MEDLINE (using both PubMed and Ovid), the Cumulative Index of Nursing and Allied Health Literature (CINAHL) and Web of Science for articles published between January 1975 and July 2020. Quality of the studies was assessed using the National Institute of Health checklist.

Results

From 2850 screened articles, 26 fulfilled the inclusion criteria. Measurement of blood prednisolone with or without cortisol was used in eight studies as a measure of oral corticosteroid adherence, and fractional exhaled nitric oxide (FeNO) in 17 studies for inhaled corticosteroid adherence. Inhaled corticosteroids were measured directly in the blood in one study. By direct measurement of drug levels in the blood, adherence rates to oral corticosteroids ranged from 47% to 92%, although the performance and timing of the test were often not known, making interpretation of findings and serum prednisolone concentrations difficult. FeNO is generally lower in adherent than non‐adherent patients, but no absolute cut‐off can be proposed based on the available data. However, a fall in FeNO following supervised inhaled corticosteroid dosing could indicate previous poor adherence.

Conclusions and Clinical Relevance

Despite prednisolone and cortisol levels commonly being used as adherence markers in clinical practice, further work is required to assess the influence of the dose and timing on blood levels. The promising findings of FeNO suppression testing should be explored in further prospective studies.