Background: Trials of cognitive-behavioral interventions (CBI) designed to reduce symptom severity or improve dimensions of quality of life seldom consider how the side effects of treatment or the complications imposed by the disease or treatment may moderate the impact of the trial on the designated outcome. To address this issue, the moderating effect of neutropenia on the impact of a CBI for reducing symptom severity was evaluated among patients with cancer undergoing chemotherapy.
Methods: The authors described the impact of a randomized trial of a 10-contact, 20-week CBI on symptom severity, as well as the moderating effect of a neutropenic episode on symptom severity at 20 weeks. Severity scores were based on sum scores (0-10) for 15 symptoms.
Results: There was an effect for age (younger) and group on severity at 20 weeks and an interaction between neutropenia and group. Among patients with no evidence of neutropenia, those in the experimental arm had a 9-point lower severity score at 20 weeks. Among patients who experienced neutropenia, differences in symptom severity by arm of the trial were < 3 points. Further, fatigue, fever, and pain were more prevalent among patients with neutropenia.
Conclusions: Patients who experienced neutropenia did not benefit from a CBI to lower symptoms. The overall effect of this intervention came almost exclusively from patients without neutropenia.