Sleep wearables
Participants wore the Fitbit Alta HR (Fitbit Inc., 2017 release) on their non-dominant hands. The Fitbit Alta HR has been found to provide equivalent estimates to research-grade actigraphy for sleep parameters such as TST, sleep latency, sleep efficiency and WASO, in and outside of the laboratory [Participants were given a Dreem headband (Rhythm SAS., version 1) to wear on their head while sleeping. Compared to PSG, Dreem had high concordance for raw signal detection with 83.5% accuracy for overall scoring across five stages (i.e. all sleep stages and wake) and 74.0% accuracy with wake epochs alone (i.e. specificity) [