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Night-time activity forecast by season and weather in a longitudinal design: natural light effects on three years' rest-activity cycles in nursing home residents with dementia

Wahnschaffe, A., Nowozin, C., Rath, A., Floessner, T., Appelhoff, S., Muench, M. & Kunz, D., Dec-2017, In : International Psychogeriatrics. 29, 12, p. 2071-2080 10 p.

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  • Night-time activity forecast by season and weather in a longitudinal design

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DOI

  • Amely Wahnschaffe
  • Claudia Nowozin
  • Andreas Rath
  • Theresa Floessner
  • Stefan Appelhoff
  • Mirjam Muench
  • Dieter Kunz

Backround: Night-time agitation is a frequent symptom of dementia. It often causes nursing home admission and has been linked to circadian rhythm disturbances. A positive influence of light interventions on night-time agitation was shown in several studies. The aim of our study was to investigate whether there is a long-term association between regional weather data (as indicator for daylight availability) and 24-hour variations of motor activity.

Methods: Motor activity of 20 elderly nursing home residents living with dementia was analyzed using recordings of continuously worn wrist activity monitors over a three-year period. The average recording duration was 479 206 days per participant (mean SD). Regional cloud amount and day length data from the local weather station (latitude: 52 degrees 56N) were included in the analysis to investigate their effects on several activity variables.

Results: Nocturnal rest, here defined as the five consecutive hours with the least motor activity during 24 hours (L5), was the most predictable activity variable per participant. There was a significant interaction of night-time activity with day length and cloud amount (F-1,F-1174 = 4.39; p = 0.036). Night-time activity was higher on cloudy short days than on clear short days (p = 0.007), and it was also higher on cloudy short days than on cloudy long days (p = 0.032).

Conclusions: The need for sufficient zeitgeber (time cue) strength during winter time, especially when days are short and skies are cloudy, is crucial for elderly people living with dementia. Activity forecast by season and weather might be a valuable approach to anticipate adequately complementary use of electrical light and thereby foster lower night-time activity.

Original languageEnglish
Pages (from-to)2071-2080
Number of pages10
JournalInternational Psychogeriatrics
Volume29
Issue number12
Publication statusPublished - Dec-2017

    Keywords

  • rest-activity cycle, agitation, dementia, light, season, weather, circadian, ACTIVITY RHYTHM DISTURBANCES, BRIGHT-LIGHT, ALZHEIMERS-DISEASE, CIRCADIAN-RHYTHMS, PHYSICAL-ACTIVITY, INSTITUTIONALIZED PATIENTS, MELATONIN SECRETION, CONTROLLED-TRIAL, ELDERLY SUBJECTS, SLEEP QUALITY

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