Subgroup analysis of symptoms and their effect on functioning, exercise capacity, and physical activity in patients with severe chronic obstructive pulmonary disease.
BACKGROUND
Little is known about symptom clusters and their effect on outcomes in people with chronic obstructive pulmonary disease (COPD).


OBJECTIVE
To determine whether subgroups of patients with COPD could be identified by symptom ratings, whether they differed on selected demographic and clinical characteristics, and whether they differed on functioning, exercise capacity, and physical activity.


METHODS
Subjects with severe COPD (n = 596) were drawn from the National Emphysema Treatment Trial dataset. Data were drawn from questionnaires and clinical measures.


RESULTS
Two subgroup clusters emerged from four symptoms. Mean age and the proportion of participants with higher education, higher income levels, and using oxygen at rest were significantly different between subgroups. Participants with high levels of symptoms had lower functioning and decreased exercise capacity. Symptom cluster subgroups were significantly associated with social functioning.


CONCLUSIONS
These findings suggest that screening for high levels of symptoms may be important in patients with severe COPD.
School of Nursing, Korea University, 145 Anam-Ro, Seongbuk-gu, Seoul, Republic of Korea. Electronic address: sookyung.park7@gmail.com.
Soo Kyung
SK
Park
Catherine A
CA
Meldrum
Janet L
JL
Larson
D000203:Activities of Daily Living; D000367:Age Factors; D000368:Aged; D004417:Dyspnea / Q000209:etiology; D017079:Exercise Tolerance; D005221:Fatigue / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology* / Q000523:psychology; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires
Chronic obstructive pulmonary disease; Functioning; National Emphysema Treatment Trial; Symptom clusters; Symptoms