Feasibility of the duration of actigraphy data to illustrate circadian rhythm among cognitively intact older people in nursing home: cosinor analysis

Assessment of sleep is an important determinant of health. Moreover, sleep assessment is quite difficult in elderly people; getting consent for participation in the study, spending more time due to cognitive and communicative disruptions, having difficulties in accessing to individuals, and higher withdrawal rate of elderly people than adults occur as additional difficulties. The objective of the study was to determine whether 1-day measurement could be enough to determine the circadian rhythm of cognitively intact older adults in nursing home. A sample of the study consisted of individuals living in three nursing homes with similar environmental conditions and who were independent in daily living activities. The exclusion criteria were severe health problems, severe neurological and mental diseases, and severe hearing loss and cognitive impairment. Continuous actigraphy monitoring was performed in 52 older adults who met the sampling criteria over a 4-day period. Cycle mesor, amplitude, acrophase, and R2, calculated using 1 to 4 days of data and each day of data, were compared. For amplitude, acrophase and R2 parameters, there was no statistically significant difference between 4-day measurement and 1-day measurement (p > 0.05). However, for mesor parameter, there was no significant difference between 1-day, 2-day, and 3-day measurements, and differentiation was observed in 4-day measurements. A daily measurement could be used to determine the circadian rhythm of actigraphy in cognitively intact older adults in nursing home. However, further studies are required to better understand and support our findings.