UDS forms and documentation

Please note that the RDD is different from the basic Data Element Dictionary (DED) that NACC provides for each packet of forms. The DED defines every variable in a given form in the order in which it appears. This one-to-one correspondence is not found in the RDD, however, because of the use of derived variables and other ways of creating consistency across all three UDS versions.

The Researcher’s Data Dictionary — Uniform Data Set (RDD-UDS) is intended to be the first and primary resource for researchers analyzing NACC clinical and demographic data. The RDD-UDS brings together information for the original data-collection instruments for all past and current UDS form versions.

RDD-UDS button

The RDD-UDS is designed as a comprehensive description of the data elements available to researchers from all versions of the UDS Forms — Version 1.2, Version 2, and Version 3. Versions 2 and 3 correspond to the two major revisions that the NACC Uniform Data Set has undergone since its inception in 2005. The more substantial of the two revisions, Version 3, was implemented in 2015. Among its significant updates, Version 3 now incorporates the 2011 NIA-AA criteria for Alzheimer’s dementia, a diagnosis of vascular brain injury, a more detailed family history form, and an updated neuropsychological battery.

One result of the Version 3 revision is that several data elements collected in v1.2 and v2 of the UDS are not collected in v3, and vice-versa. We have accommodated these differences as follows: CONTINUE READING …

  • A code of -4 is used to bring attention to data not collected due to differences in form versions: "-4 = Not applicable: UDS form submitted did not collect data this way, or a skip pattern precludes response to this question." In this document, these structurally missing data will be indicated as "Not applic" (Not applicable) in the tables that accompany each variable.
  • Similarly, v1.2 of the UDS did not include a Telephone Follow-up Packet, and so for v1.2, the "TF" cell in the tables is grayed out.
  • A number of original data elements have blank values dictated by skip patterns. These blanks have been reset to the appropriate codes (e.g., not applicable, not available, or not present).
  • To provide consistent coding across all versions of the UDS, derived variables were created from the original source variables. In analysis files, these derived variables often replace the original UDS variable. Derived variables are named with the prefix "NACC," while original UDS variables do not have a specific prefix.

IMPORTANT NOTE: When selecting variables for data analysis, be sure to review all data elements in the section of interest. Some variables differing across forms could not be combined into a single derived variable. For example, Versions 1.2 and 2 use one way of recording the method used to arrive at a clinical diagnosis, and Version 3 uses another. In a case like this, both original source variables are provided. Thus, the investigator will need to decide how to analyze these data keeping in mind the inconsistency.

 

Forms and documentation for current and past UDS versions

UDS Version 3

UDS Version 2

 

UDS v2 (no longer in use for data collection)

Forms Packet

Initial Visit

Follow-up Visit

Telephone Follow-up

Coding Guidebook

Initial Visit

Follow-up Visit

Telephone Follow-up

Data Element Dictionary

Initial Visit

Follow-up Visit

Telephone Follow-up

Neuropsych Battery

Neuropsych Tests, English (Account required)

Instructions, English

Neuropsych Tests, Spanish (Account required)

Instructions, Spanish

Please note that because of our licensing agreements with test publishers, we must restrict access to the v2.0 neuropsychological battery to those with ADC affiliation and an account on the NACC website. Copies of unmodified versions of these forms may be obtained directly from the appropriate publisher, as referenced in the relevant version of the UDS Coding Guidebook. If you have any questions, please email us at naccmail@uw.edu.

Milestones

Milestones Form

Instructions

Data Element Dictionary

UDS Version 1.2

 

UDS v1.2 (no longer in use for data collection)

Forms Packet, English

Initial Visit

Follow-up Visit

Coding Guidebook

Initial Visit

Follow-up Visit

Data Element Dictionary

Initial Visit

Follow-up Visit

Neuropsych Battery

Neuropsych Tests, English (Account required)

Instructions, English

Neuropsych Tests, Spanish (Account required)

Instructions, Spanish

Please note that because of our licensing agreements with test publishers, we must restrict access to the v1.2 neuropsychological battery to those with ADC affiliation and an account on the NACC website. Copies of unmodified versions of these forms may be obtained directly from the appropriate publisher, as referenced in the relevant version of the UDS Coding Guidebook. If you have any questions, please email us at naccmail@uw.edu.

Milestones

Milestones Form

Instructions

Data Element Dictionary