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Measuring dose in a tailored lighting intervention to improve sleep and mood in Alzheimer's disease patients
Author(s) -
Figueiro Mariana G,
Page Erik,
Rea Mark S
Publication year - 2020
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1002/alz.037168
Subject(s) - pittsburgh sleep quality index , dementia , mood , circadian rhythm , medicine , intervention (counseling) , physical therapy , gerontology , psychology , disease , sleep quality , psychiatry , cognition
Background Daytime light helps consolidate sleep in persons with Alzheimer's disease and related dementia (ADRD), but light levels required are high and available lighting fixtures cannot deliver the light level and spectrum needed for the circadian system. Moreover, ambient light levels cannot be measured to determine treatment dose. The present study tested whether a tailored lighting intervention could improve sleep in eight ADRD patients living in long‐term care facilities and used a novel device to measure light dose (RAD). Method In a crossover, repeated‐measures design, we exposed ADRD participants (MMSE<24) to an active (circadian stimulus, CS=0.3) and inactive (CS=0.1) tailored lighting intervention for successive 4‐week periods, spaced by a 4‐week washout period. RAD devices, calibrated to measure circadian light, were placed in spaces where the intervention was administered. The lighting intervention was energized from wake time until 6:00 pm. Measures of sleep disturbances (Pittsburgh Sleep Quality Index, PSQI and actigraph) and mood (Cornell Scale for Depression in Dementia, CSDD) were collected at baseline and during the last weeks of each intervention periods. Result Compared to their respective baseline conditions, the active lighting intervention significantly decreased wake percent and increased sleep percent. Compared to baseline and to the inactive intervention, PSQI scores reduced in the active intervention. Depression scores were significantly lower after the active than after the inactive intervention. The mean ± SEM PSQI scores was 10.9±1.1 and 7.3±0.7 at baseline and after active intervention and 10.0±1.0 and 10.3±1.6 at baseline and after the inactive intervention. The mean ± SEM CSDD scores was 9.0±1.7 and 8.0±1.3 at baseline and after active intervention and 12.0±1.6 and 12.0±2.1 at baseline and after the inactive intervention. Conclusion When carefully delivered to patients’ eyes and monitored with a calibrated instrument, daytime light can improve sleep and mood in nursing home residents with AD/ADRD. Additional data need to be collected to extend these preliminary results.