Monitoring Activity‐Rest Rhythms in Terminal Cancer Using Nonwearable Devices: A Preliminary Observational Study

Background: Disruptions in activity‐rest rhythms are common in terminal cancer patients, yet continuous monitoring of these changes is challenging. The effects of opioids and psychotropic drugs on sleep quality remain inadequately understood. Objectives: (i) To objectively evaluate temporal changes in diurnal (8:00 a.m.–8:00 p.m.) and nocturnal (8:00 p.m.–8:00 a.m.) activity‐rest rhythms over the final 2 weeks of life in terminal cancer patients using a nonwearable actigraph and (ii) to assess the adjusted impact of opioid and psychotropic drug use on these rhythms. Design: A longitudinal study. Settings/Participants: Twenty‐six terminal cancer patients in a Japanese palliative care unit. Measurements: A nonwearable actigraph was placed under the mattress to continuously monitor activity‐rest rhythms. Measured parameters included time in bed (TIB: minutes), total sleep time (TST), wake after sleep onset (WASO), sleep efficiency (SE: 0%–100%), activity score (0–960 counts/min; higher values indicate greater activity), and movement index (MI: percentage of time moving in bed; higher values suggest restlessness). Results: As death approached, diurnal TIB and SE increased, indicating reduced daytime activity. Nocturnal sleep metrics fluctuated irregularly, with an increase in MI, suggesting deteriorating sleep quality. Opioid users exhibited a higher MI and lower SE both day and night compared to nonusers. Psychotropic drug users showed a decreased nocturnal MI and improved SE. Conclusion: Terminal cancer patients experience decreased daytime activity and unstable nocturnal sleep as death nears. Opioid use correlates with inadequate rest, while psychotropic drugs may enhance nocturnal sleep quality. Continuous nonwearable monitoring offers valuable insights for optimizing end‐of‐life care.