TABLE 1

Model Fit Statistics for Age-Period-Cohort Model of Adolescent Sleep in the United States

Model ParameterChange in Deviance (Degrees of Freedom)
≥7 Hours of Sleep/NightAdequate Sleep
Age
Age-drift411.5 (1)a219.53 (1)a
Age-cohort123.7 (4)a14.29 (4)a
Age-period-cohort37.2 (4)a17.22 (4)a
Age-period−54.1 (–4)a−5.29 (–4)
Age-drift−106.7 (–4)a−26.23 (–4)a
  • a Fit statistics are based on an iterative model building strategy, beginning with an age effect and then testing whether the model is significantly improved in fit when drift is added as a parameter, then cohort, then age, period, and cohort. Parameters are then removed from the full age-period-cohort parameterization to determine whether the model fit significantly decreases. The values in the table represent the change in deviance; significant positive parameters indicate that the model has significantly improved, and significant negative parameters indicate that the model has significantly worsened.