Abstract TU117: Ecological momentary assessment of sleep disturbances, fatigue, and physical activity among Thai older adults receiving hemodialysis

Background: Older adults receiving hemodialysis in Thailand frequently experience sleep disturbances, fatigue, and low physical activity (PA). Although prior studies have described daily and diurnal variations in these symptoms, they have not investigated how hemodialysis treatment itself influences symptom patterns throughout the day. This study aimed to (1) compare sleep, fatigue, and PA between dialysis and non-dialysis days and (2) examine associations between ultrafiltration volume and these behaviors. Method: Time-based ecological momentary assessment sampling was performed over 7 days. Participants wore an ActiGraph continuously and responded to four daily text-message prompts assessing sleep (modified Brief Pittsburgh Sleep Quality Index) and fatigue (0–10 scale). Hemodialysis treatment data, including ultrafiltration volume, were collected after each session. Descriptive statistics and generalized estimating equations were used for analysis. Results: Thirty-five participants (69% male; mean age = 66.2 ± 7.4 years) completed 895 of 980 possible fatigue assessments (91.3%) and provided 228 days and 233 nights of ActiGraph data (93.1% and 95.1% of possible observations, respectively). Compared with non-hemodialysis days, participants reported significantly higher fatigue in the afternoon (β = 1.15, p < 0.001), evening (β = 3.00, p < 0.001), and night (β = 2.73, p < 0.001) of dialysis days, but not in the morning (β = –0.30, p = 0.153). On dialysis days, total sleep time, step count, and moderate-to-vigorous PA were significantly lower than on non-dialysis days after adjusting for age and BMI (p < 0.05). Higher ultrafiltration volume was associated with self-reported poorer sleep quality (β = -0.35, p < 0.05) and higher morning fatigue (β = 0.55, p < 0.01). Conclusion: This study demonstrates that older adults receiving hemodialysis experience a marked day-to-day and diurnal symptom burden, characterized by increased afternoon, evening, and nighttime fatigue, shorter sleep duration, and reduced PA on dialysis days compared with non-dialysis days. Ultrafiltration volume was independently associated with poorer self-reported sleep quality and greater morning fatigue, though it was not related to PA. These findings highlight the importance of tailoring fluid management strategies and developing interventions that mitigate fatigue and sleep disruption to improve daily PA in this population.