Sleep duration and mortality hazard ratios in the Semmelweis Study

Researchers followed adults in a Hungarian health study and compared their usual sleep durations. They linked participants’ sleep reports with later death records. The results suggested that people sleeping around seven to eight hours had the lowest death risk, while shorter or longer sleep was linked with higher risk. A hazard ratio, a comparison of the chance of an event between groups, shows an association but cannot prove that sleep duration caused the deaths.

What this means for you: This does not justify buying a sleep gadget or taking a sleep supplement. Aim for enough regular sleep, but remember that unusually long sleep may also signal illness rather than cause it.