Earlier quoted context omitted.
Not fully known but increasing evidence. Pretty stunning result is the discontinuity in all causes dementia for NHS seniors in Wales with the week of birth as the discontinuity point (week of birth is cutoff qualifier for a shingles vaccine)
I don’t understand. What do you mean by week of birth as the discontinuity point?
> To provide causal as opposed to merely correlational evidence on this question, we take advantage of the fact that in Wales eligibility for the herpes zoster vaccine (Zostavax) for shingles prevention was determined based on an individual’s exact date of birth. Those born before September 2 1933 were ineligible and remained ineligible for life, while those born on or after September 2 1933 were eligible to receive the vaccine.
Basically, the people born around that date are about as perfect a control-vs-experimental group split you can get in a large population.