Clinical Data FAQ

Q1: How do I get the clinical data?

A1: The clinical data set may be downloaded from LONI here (authorized users only).

The ADNI Biostatistics Core at UC Davis has provided a tutorial on downloading and importing the data into SAS, Stata, and R.

Q2: How is missing data coded in the datasets?

A2: Missing data is coded with -1 and -4. Generally, -4 is used for "passively" missing or not applicable (e.g. item is not collected at a particular visit), and -1 is used for data which is confirmed missing at point of data entry.

Q3: Which column in all the CSV files is the ADNI subject ID number correspondent to the "Subject ID" number in the LONI-ADNI database, the "ID" column or the "RID" column?

A3: In the ADNI subject IDs of the form 123_S_5678, the last 4 digits correspond to the roster ID (RID) which you see in every CSV file. You can also refer to the adni_roster table which lists RIDs and their associated PTIDs (of the form 123_S_5678).

Q4: Where can I find a copy of the cognitive assessment worksheets (ADAS-Cog, etc.) used to score patients at each visit?

A4: There are three versions of the ADNI cognitive assessments (baseline, month 6, month 12). Refer to Cognitive Assessment section of the Procedures Manual for information regarding cognitive assessments at visits other than BL, M6 and M12.

Q5: Where can I find ADAS-Cog total scores?

A5: Item level scores and two versions of total scores are available in the adni_adasscores file. TOTAL11 corresponds to the total score on the 11-item ADAS (items 4 and 13 omitted) and TOTALMOD corresponds to the total score on the modified 13-item ADAS (item 13 omitted).

ADAS-Cog Modified ADAS-Cog
(TOTAL11) (TOTALMOD)
Rosen et al., 1984 (modified Mohs, 1994)* Petersen et al., 2005
1 Word Recall 10 10
2 Commands 5 5
3 Construction 5 5
4 Delayed Word Recall -- 10
5 Naming 5 5
6 Ideational Praxis 5 5
7 Orientation 8 8
8 Word Recognition 12 12
9 Recall Instructions 5 5
10 Spoken Language 5 5
11 Word Finding 5 5
12 Comprehension 5 5
14 Number Cancellation -- 5
Total 70 85

* unpublished manual

Raw item level responses are available in the adni_adas file.

Q6: What is the meaning of the visit identifier "Not Yet Determined" (NV)?

A6: The NV ("No Visit" or "Not Yet Determined") visit code is applied when we receive scan QC data (e.g. mrinclusio) before we receive scan information sheets (e.g. mrimeta). In these instances, we do not yet know with which visit the scan QC data is associated.

Occasionally scan QC and scan information records which should be linked are not linkable because of discrepant data (e.g. exam dates do not match). The NV data code will be used in these cases as well, until the discrepancies are corrected.

Files:

Topic permissions

Attachment sort Action Size Date Who Comment
adniproceduresmanual12.pdf manage 24528.7 K 06 Sep 2007 - 15:28 KarenCrawford ADNI Procedures Manual
BLCogTestingWorksheet.pdf manage 1516.3 K 06 Sep 2007 - 17:21 MikeDonohue BL Cog Testing Worksheet
M6CogTestingWorksheets.pdf manage 1178.6 K 06 Sep 2007 - 17:21 MikeDonohue M6 Cog Testing Worksheets
M12CogTestingWorksheets.pdf manage 1647.2 K 06 Sep 2007 - 17:22 MikeDonohue M12 Cog Testing Worksheets
ADNItraininghandout.pdf manage 665.8 K 17 Dec 2007 - 17:34 MikeDonohue Data Download Instructions
CommitteeConfirmedConversionsasof30Jan2009.pdf manage 21.1 K 24 Feb 2009 - 17:44 KarenCrawford Confirmed Conversions