engleski

Comparison of sleep parameters obtained by means of actigraphs and sleep-wake diaries

Both actigraphy and sleep-wake diaries are methods often used in adolescents’ sleep studies. However, there is a lack of data about their agreement in estimates of sleep parameters over longer period. Diary data on bedtime and wake-up time are regularly used to restrict actigraphic scoring. One alternative is to use actiwatch devices that allow for manual marking of these events. In this study we compared actigraphic and diary measurements of sleep in a group of adolescents over two weeks, using manually entered markers of bedtime and wake-up time for restriction of actigraphic scoring. During two consecutive weeks 21 secondary-school students (11 girls), aged 15-17 years, kept sleep-wake diaries and wore actigraphs (Actiwatch® ; ; ; ; ; Score, Mini Mitter Company, Inc). The participants marked the time of going to sleep and time of waking-up by pressing the marker button on actigraphs certain number of times. Good correlations between actigraphic and diary data were found both for schooldays (s) and weekends (w) for sleep onset (rs=0.98 ; rw=0.97), sleep offset (rs=0.96 ; rw=0.95), and sleep duration (rs=0.84 ; rw=0.86). Methods were not correlated for parameters of sleep latency, number and duration of night awakenings. Comparisons of mean values of sleep parameters between two methods showed somewhat different results for schooldays and weekends. On schooldays actigraphs indicated earlier sleep onset and earlier sleep offset than diaries. Both on schooldays and weekends actigraphs recorded shorter sleep duration, greater number and duration of night awakenings than diaries. In conclusion, actigraphs and sleep-wake diaries yielded similar estimates of sleep timing and sleep duration of adolescents over period of two weeks. In contrast, the methods did not agree in estimations of sleep latency and indices of night awakenings.

actigraphy; sleep-wake diaries; adolescents

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