Functional performance in patients with COPD: association with treatment regimen, GOLD group, lung function, and symptom burden in a cross-sectional study

Abstract

Background

Data suggesting that low physical activity levels are associated with increased mortality and exacerbations in patients with COPD have led to increasing interest in the role of physical activity in COPD. This study evaluated self-reported functional performance, a measure of physical activity impairment, according to current treatment regimen, lung function, symptoms, and Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2017 groups in a large sample of patients with COPD.

Methods

This multicenter, cross-sectional, observational study (study identifier: D5970R00003) included patients with COPD (≥40 years) in the USA. A self-completion questionnaire captured demographics and patient-reported outcomes, including the Functional Performance Inventory-Short Form (FPI-SF). Diagnosis and treatment history (including spirometry results) were extracted from medical charts. Multiple linear regression was used to determine the relationship between FPI-SF and FEV₁ % predicted, and FPI-SF and COPD assessment test (CAT) score.

Results

Overall, 1,775 patients participated (classified as GOLD 2017 group A, 14.8%; B, 46.6%; C, 2.6%; D, 36.0%). Physical activity impairment affected patients across all treatment regimens and GOLD groups (mean FPI-SF total score: 2.1), with the greatest impairment within FPI-SF observed for domains requiring most physical exertion, “physical exercise” and “maintaining the household” (mean FPI-SF scores: 1.7 and 1.8, respectively). Patients receiving loose triple therapy and those in GOLD group D had the highest impairment (mean FPI-SF total scores: both 1.9), and the lowest FEV₁ % predicted (55.5% and 54.7%, respectively). FPI-SF total score correlated with FEV₁ % predicted and more strongly with CAT score (all P<0.05).

Conclusion

The stronger correlation between FPI-SF and CAT scores compared to FPI-SF and FEV₁ % predicted suggests that symptoms may have a greater impact on patients’ functional performance than lung function. Further longitudinal studies are required to establish a correlation between the effect of treatment on symptoms, lung function, and physical activity.

Keywords:

• FPI-SF
• bronchodilator
• CAT score
• spirometry
• physical activity
• functional performance inventory

Data availability

All relevant data analyzed during this study are included in this published article.

Supplementary material

Table S1 Comorbidities

Acknowledgments

The authors thank all the patients and their families and the team of investigators involved in the study. The authors also thank James Pike (Adelphi Real World) for his valuable contributions. Medical writing support, under the direction of the authors, was provided by Pauline Craig, PhD, of CMC CONNECT, a division of Complete Medical Communications Ltd, Glasgow, UK, which was funded by AstraZeneca, Cambridge, UK, in accordance with Good Publication Practice (GPP3) guidelines. This work was previously published as a meeting abstract (Thorax 2017;72(Suppl 3):A1–278) in conjunction with poster presentation at the British Thoracic Society Winter Meeting, London, UK, 6–8 December, 2017.

Author contributions

All authors contributed toward conception and design of the study or analysis and interpretation of the data, drafting and revising the paper, and agree to be accountable for all aspects of the work.

Disclosure

BD and SS are employees of AstraZeneca. DJ, MS, and NB-E are employees of Adelphi Real World. This work was supported by AstraZeneca. The funder of the study was involved in study design, data analysis, data interpretation, and writing of the report. All authors had full access to all the data in the study and the corresponding author had the final responsibility for the decision to submit for publication. No restrictions were placed on authors regarding the statements made in the manuscript. The authors report no other conflicts of interest in this work.