Has anyone seen this article on BBC health? http://www.bbc.co.uk/news/business-38151180

It suggests that sleeping six hours or less a night can increase your chances of early death by 13%

The research suggests that lack of sleep and tired employees are costing UK industry £40bn, and the US a whopping £328bn. I'm not entirely convinced how they have come to those figures. Ultimately, the staff are at work and may have a slightly reduced output, but enough to evaluate?