Exploring Network Relationships Between Health Status and Frailty in COPD Patients with Multimorbidity: A Cross-Sectional Study.

BACKGROUND: Poor health status and frailty are common among patients with chronic obstructive pulmonary disease (COPD) and multimorbidity. Although poorer COPD-related health status is associated with frailty, the item-level interconnections and possible bridge items between Chronic Airways Assessment Test-assessed COPD-related health status and frailty remain unclear. OBJECTIVE: This exploratory study aimed to examine item-level network associations between COPD-related health status and frailty, identify central and bridge nodes, and characterize dependency structures. METHODS: This single-center exploratory cross-sectional study was conducted from January 2024 to December 2024 at a tertiary hospital in China. Eligible patients were consecutively recruited using convenience sampling during the predefined recruitment period, yielding an analytic sample of 170 patients who completed the questionnaire survey. COPD-related health status was assessed using the Chronic Airways Assessment Test (CAAT), and frailty was assessed using the Tilburg Frailty Indicator (TFI). Missing data in the network variables were handled using multiple imputation with predictive mean matching (PMM). Network analysis and Bayesian network analysis were used to explore item-level associations and Bayesian network-derived dependency structures. RESULTS: The mean CAAT and TFI scores were 18.26 (SD = 7.99) and 6.36 (SD = 3.22), respectively. In the undirected network, feeling down showed the highest strength (rs = 1.155), while difficulty in walking showed the highest bridge expected influence (rBEI = 0.404). In the exploratory Bayesian network, activity limitation occupied a relatively upstream position within the algorithm-derived probabilistic dependency structure. CONCLUSION: In this exploratory network analysis, feeling down and difficulty in walking showed the highest strength and bridge expected influence, respectively. Activity limitation occupied a relatively upstream position in the exploratory Bayesian network. Given the cross-sectional design, this finding represents an exploratory probabilistic dependency rather than causal influence or temporal sequence and requires validation in longitudinal or interventional studies.