Identifying the Core Symptoms in Chinese Patients of Chronic Obstructive Pulmonary Disease: A Contemporaneous Symptom Network Analysis

Abstract

Context: Patients with chronic obstructive pulmonary disease (COPD) exhibit various patterns of co-occurring complex symptoms. However, identifying core symptoms based on these distinct symptom patterns remains limited.

Objective: The aims of this current study were to explore symptom subgroups among patients with COPD based on their unique symptom experiences and to identify the core symptoms within these subgroups, along with the correlation of these core symptoms with laboratory indicators.

Methods: From May 2018 to December 2023, we recruited 252 participants with COPD through a convenience sample in China. Participants were investigated using the Revised Memorial Symptom Assessment Scale (RMSAS). Latent profile analysis (LPA) was conducted to identify symptom subgroups, while network analysis was used to reveal core symptoms among subgroups identified by LPA.

Results: Based on symptom experiences, two subgroups of patients were identified: the "low" symptom burden subgroup and the "high" symptom burden subgroup. In both the total sample and the low symptom burden subgroup, "feeling sad" was identified as the core symptom, whereas "feeling drowsy" was the core symptom in the high symptom burden subgroup. The neutrophil-to-lymphocyte ratio was associated with the severity of drowsiness.

Conclusion: This study highlights the heterogeneity among COPD patients with multiple symptoms, resulting in the identification of two distinct symptom subgroups. Addressing symptoms of sadness and drowsiness may serve as a crucial target for alleviating the overall symptom burden in individuals with COPD.

Keywords: COPD; core symptom; heterogeneity; network analysis; symptom subgroup.

Figure 1

Estimated mean scores of 2 latent profile symptoms of multiple symptom severity.

Figure 2

Symptom networks for the total sample and two subgroups: (A) Total sample, (B). Low symptom burden subgroup, and (C) High symptom burden subgroup. The dark nodes represent the nodes with the highest intensity, and light colors represent other nodes. The circles depicted in green illustrate the core symptoms. 1: Shortness of breath; 2: Dry mouth; 3: Lack of energy; 4: Cough; 5: Feeling nervous; 6: Feeling sad; 7: Feeling irritable; 8: Worrying; 9: Feeling drowsy; 10: Difficulty sleeping; 11: Pain; 12: Difficulty concentrating; 13: Problems with sexual interest or activity; 14: Swelling of arms and/or legs; 15: I do not look like myself.

Figure 3

Centrality indices of the networks of the total sample and two subgroups: (A) Strength, (B) Closeness, (C) Betweenness, and (D) Expected Influence.