Question

Question Posted 11/02/17:
Could you please expand on one of the FAQs:
"How are patients who transitioned from normal to MCI or MCI to AD identified?"

I am looking at the tables from Diagnosis section:
ADSXLIST.csv
BLCHANGE.csv
DXSUM_PDXCONV_ADNIALL.csv

It's not clear to me which columns from these tables represent the MCI subjects who later convert to AD or not.

Could you please help.

Thanks
Response posted 11/02/17 by Danielle:
All diagnostic information is included in DXSUM_PDXCONV_ADNIALL.csv. For ADNI-1, diagnostic change information is contained in several variables (DXCURREN, DXCONV, DXCONTYP). For ADNI-GO/2, all diagnosis information is included in the variable DXCHANGE. Refer to the data dictionary for coding information.
Response posted 02/28/18 by sharvari gujja:
Thank you for the reply. Looking at the diagnostic summary table the viscode2 column includes a time point 'sc'. Could you please clarify what the visit code 'sc' means?

Thanks
Response posted 02/28/18 by Danielle:
VISCODE2="sc" is for the screening visit (which occurs before the baseline visit). For diagnosis purposes, the Clinical Core recommends using the diagnosis at the baseline visit (rather than the screening visit) as the initial diagnosis.