Description of the NACC database

The NACC database is made up of three main research data sets:

1. The UDS, a longitudinal data set

From 2005 to the present, ADCs have been contributing data to the Uniform Data Set (UDS), using a prospective, standardized, and longitudinal clinical evaluation of the subjects in the National Institute on Aging's ADC Program.

The UDS was expanded with two modules — one to collect detailed clinical information related to frontotemporal lobar degeneration (the FTLD Module, implemented in 2012), and one to collect information on Lewy body disease (the LBD Module, implemented in 2015). Both modules are completed by ADCs on a voluntary basis.

Data collection for the UDS, including the FTLD and LBD Modules, is ongoing. For more detailed information, please see Table 1 below.

2. The Neuropathology Data Set

The Neuropathology Data Set (NP) contains autopsy data for a subset of both MDS and UDS subjects. Please note that changes in diagnostic criteria and staining methods may limit the available data for certain analyses.

Data collection for the Neuropathology Data Set is ongoing. Please refer to Table 2 below for more detailed information.

3. Data collected before the UDS: The Minimum Data Set

Beginning in 1984 and ending with the 2005 implementation of the UDS, brief, single-record descriptions of ADC subjects were collected retrospectively to form the Minimum Data Set (MDS).* Please see the last table below for more detailed information.

*Because of the lack of detailed, longitudinal, and standardized clinical data in the MDS, the utility of the MDS for research is limited, and combining the clinical data in the MDS with the UDS is generally not recommended.

More information about NACC data:

Tables: An overview of the NACC database

  THE UNIFORM DATA SET (UDS)  (LONGITUDINAL) As of the March 2019 data freeze
UDS FTLD Module LBD Module
Years covered Sep 2005 – present Feb 2012 – present March 2015 – present
Study subjects Enrollees followed at ADCs (with or without dementia)
Approx # of subjects** 40,031 2,171 58
Approx # of variables 725 379 397
Method
of data collection		 Collected prospectively by clinicians, neuropsychologists, and other ADC research personnel, using up to 18 standardized forms at each visit. Some forms also have Spanish-language and telephone versions. Collected prospectively by clinicians, neuropsychologists, and other ADC research personnel, using up to 13 standardized forms at each FTLD Module visit. Collected prospectively by clinicians, neuropsychologists, and other ADC research personnel, using up to 14 standardized forms at each LBD Module visit.
Time period covered for each subject Initial UDS visit and each annual follow-up visit, plus milestones such as death or dropout Initial FTLD Module visit and annual follow-up visit Initial LBD Module visit and annual follow-up visit
Topics covered (brief list)
  • Sociodemographics on subject and co-participant
  • Family history
  • Dementia history
  • Neurological exam findings
  • Functional status
  • Neuropsychological test results
  • Clinical diagnosis
  • Imaging availability
  • APOE genotype
  • Family history
  • Neurological and motor exam findings
  • Clinical bvFTD and PPA findings
  • Neuropsychological test results
  • Social norms
  • Social behavior
  • Co-participant questionnaires
  • Imaging availability
  • Clinical symptoms and exam
  • Motor exam, activities of daily living
  • Neuropsychiatric inventory
  • Sleep behaviors
  • Neuropsychological test results
  • Genetics
  • Neuroimaging available
  • Other labs and findings
  • Clinical DLB and PD features
Publications describing data set    
Links to data forms, guidebooks, and DEDs UDS data forms, guidebooks, and data element dictionaries FTLD data forms, guidebooks, and data element dictionaries LBD data forms, guidebooks, and data element dictionaries

 

  THE NP DATA SET  As of the March 2019 data freeze
Data with associated UDS visit(s) Data with no associated UDS visit (MDS only)
Years covered 2005 – present 1984 – 2005
Study subjects UDS subjects who died
and underwent autopsy 		MDS-only subjects who died
and underwent autopsy
Approx # of subjects** 5,636 11,138
Approx # of variables 85
Method of data collection Standardized neuropathology form, completed by neuropathologist
Time period covered for each subject Status of brain at autopsy Status of brain at autopsy
Topics covered (brief list)
  • Demographics
  • Date of death
  • Presence or absence of neuropathological features of most major dementias
Publications describing data set
Links to data forms, guidebooks, and DEDs Neuropathology data form, guidebook, and data element dictionary

 

  THE MINIMUM DATA SET   As of the March 2019 data freeze
Years covered 1984 – 2005
Study subjects Enrollees followed at ADCs (with or without dementia)
Approx # of subjects** 74,397
Approx # of variables 67
Method of data collection Mainly abstracted retroactively from ADC medical records
Time period covered for each subject Mainly status on last ADC visit; some variables also capture initial-visit status
Topics covered (brief list)
  • Demographics
  • Cognitive status
  • Clinical diagnosis
  • Selected clinical manifestations
  • Comorbid conditions
  • MMSE score
  • Vital status
Publications describing data set Beekly 2004
Links to data forms, guidebooks, and DEDs Minimum Data Set data form, submission manual, and data element dictionary