A new theory to explain the role of hippocampal replay, new methods to visualize synaptic ultrastructure, and the continued decline of age-adjusted dementia rates
The decline in age-adjusted dementia prevalence is superficially at odds with the CDC's reporting of a secular increase in age-adjusted AD death rates.
How might these be reconciled?
1. Dramatic reduction in the incidence of non-AD dementia offsetting an increase in AD.
2. Changes in diagnosis of AD and/or coding of deaths.
3. A statistical artifact where age-adjustment doesn't completely offset the effect of fewer deaths from other causes.
I don't know where to find the data to test these hypotheses, though. Do you know what causes this apparent discrepancy?
My guess is that it is mostly (2) -- AD is being more recognized as a cause of death -- and (3) -- because we are getting better at treating other things such as cardiovascular disease, more deaths are from AD. Also could be (1) -- "AD" is being diagnosed more rather than the generic "dementia". If I recall correctly, this shift in diagnosis started in the 1980s and may have still been occurring in the 1990s.
I don't know where to find the data to test these hypotheses, though. This sounds like a pretty in-depth epidemiology project to me.
We see a near doubling between 1999 and 2019. I wonder if anybody has worked out a model of how age standardization might not fully correct for the effects of people surviving other diseases. I'll see if I can find something.
The decline in age-adjusted dementia prevalence is superficially at odds with the CDC's reporting of a secular increase in age-adjusted AD death rates.
How might these be reconciled?
1. Dramatic reduction in the incidence of non-AD dementia offsetting an increase in AD.
2. Changes in diagnosis of AD and/or coding of deaths.
3. A statistical artifact where age-adjustment doesn't completely offset the effect of fewer deaths from other causes.
I don't know where to find the data to test these hypotheses, though. Do you know what causes this apparent discrepancy?
Hello and thank you for the interesting comment! Perhaps this is what you are referring to: https://www.cdc.gov/mmwr/volumes/66/wr/mm6620a1.htm
My guess is that it is mostly (2) -- AD is being more recognized as a cause of death -- and (3) -- because we are getting better at treating other things such as cardiovascular disease, more deaths are from AD. Also could be (1) -- "AD" is being diagnosed more rather than the generic "dementia". If I recall correctly, this shift in diagnosis started in the 1980s and may have still been occurring in the 1990s.
I don't know where to find the data to test these hypotheses, though. This sounds like a pretty in-depth epidemiology project to me.
Sorry, I forgot the link. The one I was thinking of was slightly different (age-standardized, rather than bucketed), but same basic idea:
https://www.cdc.gov/mmwr/volumes/70/wr/mm7016a5.htm
We see a near doubling between 1999 and 2019. I wonder if anybody has worked out a model of how age standardization might not fully correct for the effects of people surviving other diseases. I'll see if I can find something.
Thanks, yeah that would make sense to me as a possible explanation. I'd be curious to hear!