Symptom Clusters in Chronic Obstructive Pulmonary Disease Patients with Insomnia: Secondary Data Analysis

People with chronic obstructive pulmonary disease (COPD) and insomnia experience multiple concurrent symptoms called a symptom cluster that can affect their daily functioning. However, limited symptom cluster research has been conducted in this population. To address this research gap, this study employed secondary data analysis and a two-phase approach. The first phase included analysis of baseline data for 102 people with COPD and insomnia to identify influencing factors and an outcome of a symptom cluster. To identify subject groups, five symptom variables were used as symptom cluster indicators: insomnia, dyspnea, fatigue, anxiety, and depression. As results, subjects were categorized into three classes (low, intermediate, and high symptom severity groups). As to associated factors and the outcome, self-efficacy for sleep, self-efficacy for COPD, and dysfunctional beliefs and attitudes about sleep were significantly associated with class membership, and the physical function outcome differed among the three groups. The second phase involved analysis of longitudinal data for 91 people with COPD and insomnia who completed baseline, post-intervention, and 3-month follow-up assessments. The aims were to examine longitudinal patterns of a symptom cluster and evaluate the effect of behavioral interventions on symptom cluster transition over time. Subjects were assigned to four intervention groups under the parent study’s 2x2 factorial design: (1) cognitive behavioral therapy for insomnia (CBT-I) + COPD education (COPD-ED), (2) attention control (AC), (3) CBT-I + AC, and (4) COPD-ED + AC. As to the findings, three classes (low, intermediate, and high symptom severity groups) were identified at each of the three assessment time points. Membership in the low and intermediate symptom severity groups at baseline was the most stable over time, while most transitions occurred in the high symptom severity group. Compared to the AC group, the CBT-I + AC and CBT-I + COPD-ED groups were more likely to show better transition, or movement toward reduced symptom cluster severity. On the whole, this study’s findings can contribute to improvement of modifiable factors associated with the symptom cluster and to development of targeted interventions for people with COPD and insomnia at high risk of symptom burden.