At the Neop conference call, they made a point of saying that they had the social security numbers of all the patients enrolled in the trials, and that there were databases available to track deaths that way.
What I think they meant was that there is something called the "Social Security Death Index." (You can look it up on Google.) It is how the Social Security Administration keeps track of everyone with a social security number that has been reported to them as being dead.
A lot of genealogy web sites have it in a searchable format for free or for a fee. However, it does not tell you how somebody died. It also does not include people who died but were not reported to Social Security as having died. (For example, if someone died before they started collecting SS checks, there would be no reason to report the death.)
Still, I have never heard of a company resorting to this to follow up old data.
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