Environmental factors related to sleep latency among inpatients in rehabilitation wards according to functional independence measure cognitive scores.

Background: No study has investigated sleep‐related environmental factors in patients according to their functional independence measure (FIM) cognitive scores. Aims: The aim of this study is to examine the associations between environmental factors such as noise and sleep latency according to the FIM cognitive scores among inpatients in rehabilitation wards. Design This is a prospective longitudinal study. Methods: This study measured the sleep state using a bed‐based actigraphy, environmental data from Environmental Sensor®, and medical record information of 33 inpatients in the rehabilitation wards during 2018. A linear mixed‐effect model was used to analyse the associations between sleep latency and environmental factors. Participants were grouped according to high or low FIM cognitive scores. Results: The average patient age was 77.2 ± 10.9 years, and 48.5% were male. In the high FIM cognitive score group, the loudness and frequency of noise exceeding 40 dB during sleep latency were significantly associated with sleep latency. In the low FIM cognitive score group, only the noise frequency was associated with sleep latency, and intra‐individual variance was larger than that of the high group. Conclusion: These findings suggest that providing night care with attention to subdued noise is important, particularly for patients with low cognitive functional independence levels measured by the FIM cognitive score. Summary statement: What is already known about this topic? Many elderly individuals have sleep disorders, such as difficulties falling and staying asleep.Environmental factors, like light and noise, influence inpatients' sleep. What this paper adds? Patients with high functional independence measure (FIM) cognitive scores had longer sleep latency when both the loudness and frequency of noise exceeded 40 dB.Patients with low FIM cognitive scores had longer sleep latency with frequent noise, regardless of loudness.Nurses should provide care with more caution, taking into consideration the frequency of noise produced, regardless of loudness, particularly for patients with a low cognitive functional independence level measured by the FIM cognitive score. The implications of this paper For elderly inpatients with a lower cognitive functional independence level measured by the FIM cognitive score, the number of nurses' visits at night should be minimized to avoid disturbing the patients' sleep by using devices such as nonwearable sleep monitoring sensors, which can also contribute to reducing nurses' burden. [ABSTRACT FROM AUTHOR]