A comparison of actigraphy scoring rules used in pediatric research

Background: The use of actigraphy in pediatric sleep research has increased over the past decade, yet few guidelines exist to help investigators with scoring and interpretation. The primary aim of this study was to compare two commonly reported non-automated rules for scoring sleep-onset and sleep-offset.

Methods: Forty children (8-12 years) wore an actigraph for one week and completed a daily sleep diary. Sleep-onset and sleep-offset were scored using the "15 minute rule" (onset: 1st of ≥ 15 consecutive minutes of sleep after reported bedtime; offset: last minute of ≥ 15 consecutive minutes of sleep prior to reported wake time) and the "3/5 minute rule" (onset: 1st of ≥ 3 consecutive minutes of sleep after reported bedtime; offset: last minute of ≥ 5 consecutive minutes of sleep prior to reported wake time). A blinded "no diary" rule was also examined (using unaided judgment to identify sleep-onset and sleep-offset).

Results: Statistical differences were found between scoring rules for sleep-offset [F (2,74)=7.68, p=.001], sleep period [F (2,74)=5.05, p=.009], wake after sleep-onset [F (2,74)=7.68, p=.001], sleep minutes [F (2,74)=3.62, p=.03], and sleep efficiency [F (2,74)=6.50, p=.003]; however, these differences were not clinically meaningful.

Conclusions: While the findings from this study suggest that data can be compared across studies that use different scoring rules, standard scoring rules are needed to ensure that reported results are valid and meaningful.