Simple slopes for the interaction effect of week-level stress and positive affect on sleep quality. Note: Marginal effects plot depicting the effect of week-level perceived stress on subjective sleep quality at three levels of week-level positive affect: 1 SD below the sample mean, at the sample mean, and 1 SD above the sample mean. Slopes derived from pooled results across imputed data sets. Analysis of simple slopes suggests that, for participants 1 SD above the mean on positive affect at the week-level, higher week-level perceived stress was associated with significantly worse subjective sleep quality. For participants at or below the mean for positive affect, perceived stress did not significantly affect sleep quality. GMC, grand-mean centered