RESUMO
PURPOSE: Engagement in physical activity (PA) is often associated with better sleep quality and less pain severity among patients diagnosed with breast cancer. However, less research has focused on whether patients' PA prior to breast surgery, including their perceived decrease in PA level, is associated with worse preoperative sleep quality, and subsequently, greater postoperative pain. This longitudinal study investigated whether patients' preoperative PA was associated with their postoperative pain. We also explored whether preoperative sleep disturbance partially mediated the relationship between preoperative PA and postoperative pain. METHODS: Prior to breast surgery, patients self-reported both their overall level of PA and whether they perceived a decrease in their PA since the diagnosis/onset of treatment for cancer. Patients also completed a measure of preoperative sleep disturbance. Two weeks after surgery, patients completed a measure of postoperative surgical-area pain severity. RESULTS: Our results showed that preoperatively perceiving a decrease in PA level was significantly associated with greater preoperative sleep disturbance and postoperative pain. A mediation analysis revealed that the association between preoperative decreased PA and postoperative pain was partially mediated by preoperative sleep disturbance. Notably, patients' overall preoperative level of PA was not related to preoperative sleep disturbance or postoperative pain. CONCLUSION: These findings suggest that maintaining, or even increasing, PA after diagnosis/treatment may be more important than the absolute amount of PA that women engage in during the preoperative period. Potentially, some patients with breast cancer may benefit from a preoperative intervention focused on both maintaining PA and bolstering sleep quality.