Rest/activity rhythm is related to the coexistence of pain and sleep disturbance among advanced cancer patients with pain

Purpose: This study aimed to explore the relationships among pain, sleep disturbance, and circadian rhythms in advanced cancer patients. Methods: This cross-sectional study was conducted in 68 cancer patients from the oncology inpatient unit of a teaching hospital. Their demographic and medical characteristics, questionnaire surveys, including Brief Pain Inventory-Chinese version and Pittsburgh Sleep Quality Index Taiwanese version, and sleep logs and actigraphic recordings in consecutive 3 days and nights were collected and analyzed. Results: The mean (SD) scores for autocorrelation coefficient at 24 h (r24) and dichotomy index (I