Is Sleep Quality More Important than Sleep Duration for Public Health?

In this issue of SLEEP, Clark and colleagues contribute an extremely large and well-conducted longitudinal study on the relationship between poor sleep and cardiovascular risk. The onset of poor sleep was the transition to short or long sleep duration from 7-8 hours of "normal" sleep, or the change from negligible to more than weekly sleep disturbance over the course of 4 years. The outcomes were based on medication reimbursements after physician confirmation of the diagnosis with the follow-up period being up to 7 years after the onset of poor sleep.