Symptoms were assessed using a face-valid
Symptom Reporting Form. We identified five symptom clusters by exploratory factor analysis.
Clusters were named ‘‘loss of energy,’’ ‘‘poor intake,’’ ‘‘autonomic dysfunction,’’
‘‘aerodigestive impairment,’’ and ‘‘pain complex.’’ We used nonhierarchical cluster analysis
to divide the 394 patients with complete data into six groups. Each group was characterized
by a particular pattern that was composed of different symptom clusters. Survival, functional
performance, bone metastasis, and fluid accumulation were significantly associated with
symptom clustering in six groups of patients. The severity of psychological distress also related
to their physical deterioration. These data suggest that different underlying mechanisms
associate with symptom clustering. Further elucidation of these processes may assist in
symptom management.