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Question Posted 05/02/13:
Dear Sirs,
I am interested in further exploring your UPENNBIOMARKER data. I understood that UPENNBIOMK provides baseline data only, that UPENNBIOMK2 includes a follow-up etc. Since I found some discrepancies in the raw data (and sample size and subjects examined) between baseline CSF assessment in UPENNBIOMK and UPENNBIOMK2 baseline values, I am not sure on which data I should rely on (I would need baseline values only). I would very much appreciate your help.
With kind regards,
Claudia Bartels
Response posted 05/06/13 by Michael J Figurski:

Short answer: if you need baseline values only for ADNI 1 patients, use the UPENNBIOMK data set.

The UPENNBIOMK2 data set contains 2 more patients at baseline and excludes one 'screen failure' patient, compared to UPENNBIOMK, but it also excludes p-Tau results due to analytical problems. Thus, if you don't need to perform any longitudinal studies with the "m12" visit, you will not benefit from using UPENNBIOMK2.

The raw results are different between each UPENNBIOMKx data set because these are results of separate analytical runs. For each data set the samples were re-analyzed again, thus their results are similar but not the same. The rationality behind this procedure is beyond the scope of this simple answer, but if you or anyone is interested in it, please post another question.

Kind regards,
Response posted 08/09/13 by Claudia Bartels:
Dear Sirs,

Unfortunately, I did not receive any feedback from you on my 2nd follow-up questions until now, so I'll try again:

Original (follow-up) questions:
Dears Sirs,
thank you for informing me on the 2nd round of biomarker analyses. I have now downloaded the recently provided dataset UPENNBIOMK6 and would like to ask for some more details.

I am interested in running some analyses on abeta 1-42, tau and ptau 1-81 baseline values and would like integrate as much subjects as possible.

With the new UPENNBIOMK6 data set I found out that – compared to the UPENNBIOMK data set – a subset of ADNI GO and ADNI II subjects are also included, but what is more, a large number of ADNI I patients were obviously not reanalyzed. Additionally, the ADNI GO subjects of the UPENNBIOMK5 data set and the ADNI GO subjects of the UPENNBIOMK6 data set do not fully overlap.

Is it reasonable (with respect to my planned approach using as much CSF baseline data as possible) to reorganize data sets such that:

- I use the recently published and valid data of UPENNBIOMK6

- I additionally integrate the data of UPENNBIOMK not included in UPENNBIOMK6 (except for ptau 1-81) and

- I additionally integrate the data of UPENNBIOMK5 not included in UPENNBIOMK6?

I would be very interested in your opinion, especially as different analyses runs would be “mixed together”.

I hope you can see my point and would very much appreciate your help on reorganizing my data.

Could you please also provide me with additional information why so many subjects were not reanalyzed (e.g. no more samples available?) in the 2nd batch of CRF analyses.

Thank you very much in advance,

All the best,

Claudia Bartels
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