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Study Objectives: To evaluate the validity and reliability of 2 new models of commercially available actigraphs compared to polysomnography for children and adolescents., Design and Setting: Subjects concurrently wore the Ambulatory Monitoring Inc. Motionlogger Sleep Watch (AMI) and the Phillips Respironics Mini-Mitter Actiwatch-2 (PRMM) while undergoing overnight polysomnography (PSG) in a pediatric sleep laboratory housed in a tertiary care children's hospital., Participants: 115 youth (59 girls, 56 boys), ages 3-18 years (mean 8.8 years, SD 4.4 years)., Measurements: Outcome variables were total sleep time (TST), wake after sleep onset (WASO), and sleep efficiency (SE). Epoch-by-epoch comparisons were made between the 2 devices and PSG to determine sensitivity, specificity, and accuracy. Agreement between the 2 devices was determined with t-tests and the Bland-Altman concordance technique. Different algorithms/sensitivities, developmental age groups, and sleep disordered breathing (SDB) status were also examined., Results: For both device brands, sensitivity (0.89-0.97), specificity (0.54-0.77), and accuracy (0.87-0.90) were similar to previous reports. Notably, compared to PSG, both device brands significantly overestimated WASO, while the AMI device also significantly underestimated TST. Inter-device comparison of the 2 brands found poor agreement for TST, WASO, and SE. Agreement with PSG differed depending on the scoring algorithm (AMI) or sensitivity setting (PRMM), as well as across developmental age group and sleep disordered breathing (SDB) status., Conclusions: Similar to previous reports, both new actigraph brands were found to have good sensitivity (to detect sleep), but poorer specificity (to detect wake). Study results also suggest that researchers should adjust the scoring algorithm/sensitivity depending on a study's design (e.g., young children vs. adolescents, healthy children vs. youth with SDB). Further, inter-device reliability was poor, suggesting the need for caution when comparing results across studies that use different brands of actigraphic devices.

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., (Copyright © 2011 Elsevier B.V. All rights reserved.)