I think you nailed it above. The focus is on mid-life, long-term risk reduction: largely healthy living, environmental and public health risks rather than short-term clinical events that accelerate pre-existing MCI or subclinical disease. Most of the delirium evidence is relatively short-term.
I share your concerns about biases in the evidence but I'm a bit less conservative about applying it where the adverse consequences of implementation are minimal. 'Lifestyle' RCTs are impossible if covering a realistic exposure period (10+ yrs ideally). But I've never sold post-MCI risk reduction.
Agreed - but the effect sizes are very large, and delirium is potentially preventable as well as potentially treatable.
I think we are missing a trick here - why not address both the longer-term risk factors as well as do what we can to understand how acute brain damage might also lead to dementia?
Also target audience makes a difference. Lancet Commission is aimed at largely at encouraging lay public lifestyle changes and health policy, not improvements in clinical practice. Delirium prevention is largely a clinical issue (although we do our best to inform lay audiences where possible).
So the LC 14 risk factors all have incontrovertible mechanistic causal links demonstrated? With targeted interventions (of those factors that are amenable to intervention) showing reduced risk?
Just give me evidence that dementia and delirium are more than simply associated with each other. One might just as easily (and more convincingly) say dementia is a risk factor for delirium.
Thanks - will reply properly tomorrow. In brief, maybe 3 types of evidence:
(a) studies looking baseline cognition to rule out existing dementia then showing that people who get delirium are at far higher risk of future dementia
(b) studies showing that people with acute systemic illness have evidence of damage to the brain (e.g. in ICU studies)
(c) animal model studies showing that in prion models peripheral inflammatory stimuli cause both (i) acute cog change, & (ii) accelerated longer-term neurodegeneration
Comments
I think we are missing a trick here - why not address both the longer-term risk factors as well as do what we can to understand how acute brain damage might also lead to dementia?
(a) studies looking baseline cognition to rule out existing dementia then showing that people who get delirium are at far higher risk of future dementia
...
(c) animal model studies showing that in prion models peripheral inflammatory stimuli cause both (i) acute cog change, & (ii) accelerated longer-term neurodegeneration
...