How "pedigreed" can a negative control person be?
Working through the slides, I'm still a bit puzzled by the labelling of "false positives" occurring on the "pedigreed negative" in Phase 2b. , and by the whole concept of a "pedigreed negative" person.
Does anyone know exactly how the person who was used as the "pedigreed negative" control came about that pedigree? Were multiple samples over time by multiple labs all in agreement that there were no signs of positivity?
Even assuming that to be the case....if even an agreed "positive" person can test negative on multiple occasions, how sure can you ever be that a person with multiple negative results is indeed negative (especially without doing tests of possible tissue reservoirs)? And that also assumes no intervening source of infection.
So, it seems to me one has to make two kinds of assumptions on a "pedigreed negative" person...but I could be missing something. If this is true, I think it's the type of thing that needs to be noted in an analysis. The slides simply treat the positive results as false positives without qualification.
Yes, they did address a procedural explanation for a possible false positive on the WPI's test, but I didn't see how that actually "verified" that the positive was false. I also didn't note any explanation of why NCI also had a positive result. So, I wouldn't treat the negative as "pedigreed" any more.
Without knowing more, if I had been doing the slides, I would have avoided the term "pedigreed" altogether, especially for the negative / control. And I would have qualified the reference to "false positives" as being only "presumptively" so, or qualified in some way.
Working through the slides, I'm still a bit puzzled by the labelling of "false positives" occurring on the "pedigreed negative" in Phase 2b. , and by the whole concept of a "pedigreed negative" person.
Does anyone know exactly how the person who was used as the "pedigreed negative" control came about that pedigree? Were multiple samples over time by multiple labs all in agreement that there were no signs of positivity?
Even assuming that to be the case....if even an agreed "positive" person can test negative on multiple occasions, how sure can you ever be that a person with multiple negative results is indeed negative (especially without doing tests of possible tissue reservoirs)? And that also assumes no intervening source of infection.
So, it seems to me one has to make two kinds of assumptions on a "pedigreed negative" person...but I could be missing something. If this is true, I think it's the type of thing that needs to be noted in an analysis. The slides simply treat the positive results as false positives without qualification.
Yes, they did address a procedural explanation for a possible false positive on the WPI's test, but I didn't see how that actually "verified" that the positive was false. I also didn't note any explanation of why NCI also had a positive result. So, I wouldn't treat the negative as "pedigreed" any more.
Without knowing more, if I had been doing the slides, I would have avoided the term "pedigreed" altogether, especially for the negative / control. And I would have qualified the reference to "false positives" as being only "presumptively" so, or qualified in some way.