The Clinical Characteristics and Outcomes in Non-Frequent Exacerbation Patients with Chronic Obstructive Pulmonary Disease in the Chinese Population

Abstract

Background

We analyzed the clinical characteristics and outcomes in non-frequent exacerbation patients with chronic obstructive pulmonary disease (COPD).

Methods

In this retrospective cohort study, we enrolled patients with stable COPD from 12 hospitals. Non-frequent exacerbation was defined as less than two times of exacerbations in the past year. The non-frequent exacerbation patients were classified into less and more symptomatic groups based on the COPD Assessment Test (CAT) and modified Medical Research Council (mMRC). Finally, the non-frequent exacerbation patients with less and more symptomatic were classified into the long-acting muscarinic antagonist (LAMA), long-acting β2-agonist (LABA)+inhaled corticosteroids (ICS), LABA+LAMA, and LABA+LAMA+ICS groups. Minimum clinically important difference (MCID) was defined as a CAT score decrease of ≥ 2 during six months of follow-up. We recorded the number of exacerbations and mortality during one year of follow-up.

Results

A total of 834 (67.5%) non-frequent exacerbation patients with COPD were included in this study. The non-frequent exacerbation patients had a higher education level and body mass index (BMI), and lower CAT and mMRC scores (P<0.05). In addition, the non-frequent exacerbation patients had lower mortality and risk of future exacerbation, and were more likely to attain MCID (P<0.05). Furthermore, the non-frequent exacerbation patients with more symptomatic COPD treated with LABA+LAMA or LABA+LAMA+ICS were more likely to attain MCID and had a lower risk of future exacerbation (P<0.05). However, there were no significant differences among the different inhalation therapies in non-frequent exacerbation patients with less symptomatic COPD.

Conclusion

The non-frequent exacerbation patients with COPD had a higher education level and BMI, a lower symptom burden, and better outcomes. In addition, LABA+LAMA should be recommended to non-frequent exacerbation patients with more symptomatic COPD, while mono-LAMA should be recommended to non-frequent exacerbation patients with less symptomatic COPD as the initial inhalation therapy.

Keywords:

• chronic obstructive pulmonary disease
• non-frequent exacerbation
• minimum clinically important difference
• mortality
• inhalation therapy

Abbreviations

BMI, Body Mass Index; COPD, Chronic Obstructive Pulmonary Disease; CAT, COPD Assessment Test; CSD, Clinically Symptom Deterioration; a95% CI, Adjusted 95% Confidence Intervals; FEV1, Forced Expiratory Volume in one second; FVC, Forced Vital Capacity; GOLD, Global Initiative for Chronic Obstructive Lung Disease; ICS, Inhaled Corticosteroids; IQR, Interquartile Range; LAMA, Long-Acting Muscarinic Antagonist; LABA, Long-Acting β2-Agonist; mMRC, Modified Medical Research Council; MCID, Minimum Clinically Important Difference; aOR, Adjusted Odds Ratio; PSM, Propensity Score Matching; RCTs, Randomized Controlled Trials.

Data Sharing Statement

All data of this study are available from the corresponding author Ping Chen for reasonable request (http://120.77.177.175:9007/a/login).

Ethics Approval and Informed Consent

This study was approved by an institutional review board from the Second Xiangya Hospital of Central South University and conducted in accordance with the Declaration of Helsinki (ChiCTR-POC-17010431). All patients were offered informed consent.

Acknowledgments

We would like to thank the staff of the hospitals for their cooperation in collecting the study data.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

All authors have no conflicts of interest for this work.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (NSFC, Grants 82270045) and Xiangya Mingyi grant (2013).