Health advice, with the evidence graded.
Every claim here is graded by the strength of the research behind it, not by how confident it sounds. Every source carries a PubMed ID, so you can check it yourself in a few seconds.
Strong. Consistent support across multiple meta-analyses.
Good, with caveats. Meta-analytic support, but limited or mixed.
Plausible. A reasonable mechanism, not enough good trials yet.
Popular, unsupported. Widely repeated; the evidence says otherwise.
Beyond Sleep Hygiene
The six-week behavioural programme for chronic insomnia
Cool room, dark curtains, no screens: sleep hygiene is the advice everyone gives, and on its own it does little to treat chronic insomnia. This book is the programme that does. It is built on stimulus control and sleep restriction, the two components that network meta-analyses of cognitive behavioural therapy for insomnia keep identifying as active.
It covers the sleep diary, how to set and adjust your own sleep window, the safety rules that come with it, and a week-by-week plan. Every source is listed with a PubMed ID.
Checked against the evidence
What doesn’t work for focus
Blue-light glasses, brain training, binaural beats, dopamine detoxes, omega-3. Twelve popular claims about concentration, checked against the meta-analyses, with every source linked.
Read the twelve claims →If we’re wrong, say so
Every source is identified by its PubMed ID. Type pubmed.ncbi.nlm.nih.gov/ followed by the number into a browser and you are reading the abstract. We prefer meta-analyses, systematic reviews and clinical guidelines to single studies.
If a source doesn’t say what we claim it says, that’s an error, and we’ll correct it. Write to contact@gradedclaims.com with the claim and the PubMed ID. Corrections go into the next edition.
Nothing on this site is medical advice, a diagnosis, or a substitute for a clinician.