> This study supports the inclusion of sleep regularity in public health guidelines and clinical practice as a risk factor for cardiovascular disease.
Does it? What they're measuring seems like a very likely proxy measurement for stress. I can't tell besides employment status/hours if they measure or include that at all.
Risk factor doesn't mean causative, only that there's enough signal to use it in considering what interventions to pursue. Made-up example, maybe slightly elevated blood lipids by itself wouldn't merit lipid lowering agents, but in combination with other risk factors like high blood pressure or poor sleep regularity, they are merited.
The field of medicine in general understands the concept of a condition being secondary to another, underlying cause and might treat it as a comfort thing but doesn't consider that with fixing the underlying.
In the "Covariates" section it mentions they're controlling for "self-reported sleep problems" such as insomnia. I imagine a relationship between stress and sleep regularity would most likely be mediated by insomnia?
To further show how my comment might be wrong: "In medicine and epidemiology, shift work is considered a risk factor for some health problems in some individuals, as disruption to circadian rhythms..."
Shift workers certainly experience more variability too though. I did it when I was in college. Your sleep schedule for work is incompatible with your personal life. Want to go to your family’s for Thanksgiving? That’s right in the middle of when you’d normally be asleep. Etc.
Although you’re probably right in the context of this study, I highly suspect when you sleep does affect things due to the evolutionary and biological significance of the circadian rhythm.
Does it? What they're measuring seems like a very likely proxy measurement for stress. I can't tell besides employment status/hours if they measure or include that at all.