Figure 1.

Enrollment, retention and actigraphy sleep data. Abbreviations: AW2, Actiwatch-2 (the actigraphy device used to objectively measure sleep patterns). *Three participants did not provide actigraphy data in 8^th grade, but were retained and provided actigraphy data in 9^th grade; therefore, the analytical sample includes 110 participants (i.e., 107 participants with at least 8^th grade AW2 data plus 3 participants with only 9^th grade AW2 data).