Actigraphy Estimated Night Sleep Duration in Preschool Children: Comparison of an Automated Algorithm and Sleep Diary...

This study aims to compare amongst preschoolers, night sleep duration derived using the automated van Hees algorithm in GGIR (GGIR_VH) against the reference Sadeh algorithm (Actilife_SD), and subjective caregiver-reported sleep diaries against Actilife_SD.

Participants were 142 preschoolers (52.1% males), age 5.5 years, from the Growing Up in Singapore Toward healthy Outcomes (GUSTO) birth cohort study. Weeklong actigraphy data was collected via the wGT3X-BT accelerometer (worn on the non-dominant wrist) with concurrent caregiver-reported sleep diaries. Analyses were conducted to compare the automated GGIR_VH and sleep diaries against the reference Actilife_SD. Intraclass correlations were calculated to compare the agreement levels. Bland-Altman plots were used to investigate the bias in the mean differences and limits of agreement (LoA). Repeated measures of ANOVAs were used to compare mean differences.

For the intraclass correlation between automated GGIR_VH and reference Actilife_SD, there was moderate agreement for the nighttime total sleep duration (r = 0.66) and poor agreement between diary and Actilife_SD (r = 0.04). Bland-Altman plots revealed a positive bias when comparing diaries against Actilife_SD, where diaries reported longer sleep duration. In contrast, there was almost no bias and smaller LoAs for the comparison between GGIR_VH and Actilife_SD. ANOVAs showed that comparisons between diary (M = 9.36, SD = 1.16) and Actilife_SD (M = 6.93, SD = 1.12); and GGIR_VH (M = 6.76, SD = 1.30) and Actilife_SD both yielded significant differences.

Overall, the automated GGIR_VH algorithm showed moderate agreement compared to the reference Actilife_SD. In contrast, sleep diaries overestimated sleep duration when compared to Actilife_SD.