They mentioned that sleep efficiency was already poor. They mentioned that the increase in sleep was achieved through increased time in bed, not increased effic

They mentioned that sleep efficiency was already poor. They mentioned that the increase in sleep was achieved through increased time in bed, not increased efficiency. Most of the restorative benefits of sleep happen during long stretches of uninterrupted sleep. If the sleep efficiency problem is due to multiple interruptions to the nights sleep, that is a very different thing than people having a hard time getting to sleep, but staying asleep once they are out. If the underlying sleep efficiency issue isn't addressed, it's not really all that surprising that there wasn't a measurable improvement in productivity.