Sleep Measurement in Toddlers From Low-income Families

(1) To examine toddler sleep in a low-income sample by comparing sleep diaries and actigraphy and (2) to assess whether toddlers are meeting the National Sleep Foundation recommendations (11-14 hours of sleep/24 hours and bedtime before 9 PM).

A convenience sample of mother-toddler dyads was recruited from 2 health care sites serving low-income communities. An actigraph was placed on the toddler's ankle and was worn for 3 days and nights. Mothers concurrently completed a sleep diary. Bedtime, nighttime sleep duration, nap duration, and 24-hour sleep duration were collected by both measures. Actigraphy data were analyzed using a combination of manufacturer's scoring algorithm and manual editing. Descriptive statistics and paired samples t-tests were conducted to examine the differences between sleep estimates by a sleep diary and actigraphy.

Twenty toddlers (aged 13-42 months) were included in the analyses. Based on actigraphy, 1 toddler went to bed by 9 PM on all 3 nights. Six toddlers achieved 11 to 14 hours of sleep measured in a 24-hour period for 1 of the 3 days, but when sleep was averaged across the study, none achieved this goal. Compared with actigraphy, sleep diaries underestimated bedtime by 1 hour, overestimated nighttime sleep duration by 2.5 hours, and overestimated 24-hour sleep duration by 2.3 hours, on average for all 3 nights.

Mothers reported significantly earlier bedtimes and longer sleep durations for their toddlers compared with actigraphy, suggesting that objective measures differ from sleep diaries in assessing sleep in toddlers from low-income families. Findings should not be generalized to populations of low-income families without replication.