Question Posted 03/19/14:
Thank you for rich information integrated in the LONI databae. I have a question about the column "DX" in the ADNI 1-GO-2 merged table. I saw the values in this field have "Dementia", "Dementia to MCI", "MCI to Dementia", "NL to Dementia", "NL to MCI" and etc. According to the dictionary, "DX" represents "diagnosis status". Is it the diagnosis status at each new visit time? Buy why there is values like "MCI to Dementia", "NL to Dementia", which is like transition state? And how could I know the MCI patient convert to Alzheimer's Disease or other dementia? where I could get this specific information? Many thanks!
Response posted 03/19/14 by Jessie, IDA:
Yes, in the ADNI Merged table, the DX is the corresponding diagnosis for the respective visit time (viscode) in that record. When the DX Status is a "transition state" like MCI to Dementia, the subject was diagnosed on that visit as having Dementia. The transition represents that visit in the visit prior, the subject was still diagnosed as MCI. You will notice that if you view a subject in consecutive visit order, there will always be a 'transition state' reported to represent the change in between visits.

To know whether the Dementia refers to Alzheimer's Disease or another dementia, you will have to refer to the Diagnostic Summary table, as opposed to the Merged table. The column DXOTHDEM will be marked with a 1 when a subject has a different form of dementia.