Subgroups of cancer patients with unique pain and fatigue experiences during chemotherapy.

CONTEXT Some cancer patients experience pain and fatigue, whereas others experience only one of the two symptoms. Yet, it is not clear who experiences these unique patterns and why. OBJECTIVES This study aimed to identify subgroups of cancer patients with unique pain and fatigue experiences in two different chemotherapy cycles to examine how selected factors influenced subgroup membership and identify how subgroups differed in concurrently measured functional limitation outcome. METHODS The sample included 276 patients with diverse cancer types from four U.S. sites. To investigate subgroups, latent profile analyses were performed. Multinomial logistic regression and one-way analysis of variance-type analyses were conducted to examine the influencing variables of subgroup membership and to examine differences among subgroups in patient outcome. RESULTS The high-pain/high-fatigue (HPHF) and low-pain/low-fatigue subgroups were found at both time points. The low-pain/high-fatigue subgroup was present only in the first chemotherapy cycle. Pain and fatigue levels significantly differentiated subgroups at each time point (all P<0.05). Across the two time points, experiencing higher depressed mood increased the risk to be in the HPHF subgroup (all P<0.01). The HPHF subgroup had the most serious limitations in activities (all P<0.01). CONCLUSION This study confirmed the existence of a unique symptom experience of pain and fatigue. This pattern should be acknowledged for symptom assessment and management.