Background: People with chronic obstructive pulmonary disease (COPD) and insomnia may experience multiple symptoms that can affect physical function, but little research has focused on symptom clusters in this population.
Objectives: This study aimed to identify subgroups of people with COPD and insomnia based on a pre-specified symptom cluster and determine whether physical function differed in the subgroups.
Methods: This secondary data analysis included 102 people with insomnia and COPD. Latent profile analysis classified subgroups of individuals sharing similar patterns of five symptoms: insomnia, dyspnea, fatigue, anxiety, and depression. Multinomial logistic regression and multiple regression determined factors associated with the subgroups and whether physical function differed among them.
Results: Three groups of participants were identified based on the severity of all five symptoms: low (Class 1), intermediate (Class 2), and high (Class 3). Compared to Class 1, Class 3 showed lower self-efficacy for sleep and for COPD management and more dysfunctional beliefs and attitudes about sleep. Class 3 showed more dysfunctional beliefs and attitudes about sleep than Class 2. Class 1 showed significantly better physical function than Classes 2 and 3.
Conclusions: Self-efficacy for sleep and for COPD management and dysfunctional beliefs and attitudes about sleep were associated with class membership. As physical function differed among subgroups, interventions to improve self-efficacy for sleep and for COPD management and minimize dysfunctional beliefs and attitudes about sleep may reduce symptom cluster severity, in turn enhancing physical function.
Keywords: chronic obstructive pulmonary disease; insomnia; latent profile analysis; self-efficacy; sleep; symptom cluster.