Using the Time-Varying Effect Model (TVEM) to Examine Dynamic Associations Between Daily Pain and Mood Assessments During 4-cycles of Chemotherapy for Gynecologic Cancer

Abstract

Chemotherapy for gynecologic (GYN) cancer leads to high symptom burden and low quality of life. Pain is common, distressing, and often co-occurs with mood symptoms (e.g. anxiety, depression). Traditional analytical methods assume a constant effect of mood on pain, even for longitudinal data. Little evidence has examined the dynamic, daily relationship between anxiety/depression and pain during chemotherapy. Thus, we aimed to examine dynamic associations between daily pain and mood during 4 cycles of chemotherapy for CYN cancer. In this secondary analysis, daily self-reported symptoms were collected for 84 days (21 days/cycle * 4 cycles) during a longitudinal study of symptoms in GYN cancer treatment. Women (N=24, M age=60.5 years) initiating outpatient chemotherapy for newly diagnosed GYN cancer rated the severity of multiple symptoms (including anxiety, depression and pain) at their worst in the past 24 hours on a validated 0 to 10 scale. We used the time-varying effect model (TVEM) to examine daily associations between mood and pain over time. The nonparametric trajectory of pain was decreasing over time, with a significant association between daily anxiety and pain from day 2 through day 80 (from day 1 to day 84, regression coefficient of anxiety range [CoR-anxiety]=0.23-0.66). The magnitude of association was stable until day 70 before decreasing. There was also a significant association between daily depression and pain until day 58 (CoR-depression=0.43-1.21), with a steady decrease in the magnitude of association over time. TVEM identified patterns of association between mood and pain that varied in magnitude over chemotherapy. Overall, the influence of anxiety/depression on pain decreased with more cycles of chemotherapy, which may suggest adaptation of pain intensity. These dynamic associations can advance understanding of relationships between mood and physical symptoms and provide insight into the everyday challenges faced by women undergoing chemotherapy for GYN cancer. A Pilot Study of Falls and Near Falls in Women with Ovarian Cancer Receiving Neurotoxic Chemotherapy. Funding: Rehabilitation Nursing Foundation. No grant number since this is a private foundation.