Good point, Marc.MarcR wrote:I think the PHS is a relative metric, not an indicator of absolute risk. "100" means maximum risk relative to other humans, not 100% risk.circular wrote:I really wonder how they can have a 100 percentile unless they have the deterministic PSEN and APP genes in there?
Here's a quote from the Dash sample report:
A PHS percentile of 99 implies that 99% of people are estimated to have an equal or lower risk than such individual. An individual with a high PHS percentile is estimated to have a higher risk than the one with a low PHS percentile, at any given age.
At age 66, with ApoE 4/4 and family history, I am sure I have a higher relative, statistical lifetime risk than my 66 year old ApoE 3/3 husband, or almost anyone else who is not ApoE 4/4 and my age. After all, jkramer65 and I are in the rare 2% of the population, so it make sense that I might be in the top 2% or so of risk. But statistically, that does not mean I have a 98%-100% chance of MCI or dementia by age 85, I believe. More like 50% probably, given my family history and the general population incidence of AD after age 85. Hopefully lifestyle and other protective and preventive measures move my actual risk either way down, or pushes it further back.
As a comparison, I probably also have a higher risk of a sunburn that 98% of the population given my skin tone (and previous basal cell skin cancer on my nose). But that does not translate to a 98% chance of malignant melanoma or even severe sunburn if I manage the environmental factors better now that I have that information.