a resource for the a.d. research community
The NACC database
Since being funded in response to an RFA in 1999, the National Alzheimer's Coordinating Center has grown in database size and research capability. The NACC database is unique in the United States for its size and capacity to support collaborative research in Alzheimer's disease and in a broad range of other neurodegenerative disease content areas.
The Minimum Data Set
Before NACC was established, the activity of the National Institute on Aging's ADC Program (est. 1984) was captured in a limited way through the Minimum Data Set (MDS), created at Rush University in 1997. The following year, NIA issued an RFA to establish an Alzheimer's disease data-coordinating center that would serve as a more permanent home for the database. Initial activity in NACC was focused on the MDS, which comprised approximately 50 data elements gathered retrospectively, providing a brief, single-record description of subjects enrolled at the ADCs. Although the MDS added some descriptive capability to the ADC Program and perhaps could identify which ADCs focused on a particular type of patient diagnosis, its direct use for research was quite limited: clinical diagnosis was not standardized, and detailed clinical and longitudinal data were not collected.
The Neuropathology Data Set
In 2002, a second data collection system was implemented when NACC worked closely with Neuropathology Core Leaders to develop a detailed data set to collect neuropathology exam data. The NP system has been revised several times to date, and a new revision reflecting the 2012 NIA-AA criteria is expected to be implemented in the next several months.
The Uniform Data Set — detail, comparability, and power
Also in 2002, NIA appointed an ADC Clinical Task Force and charged it with developing the content for a standardized longitudinal clinical evaluation for use throughout the ADC Program—an evaluation that became the Uniform Data Set (UDS). NACC worked closely with NIA, the Clinical Task Force, and the ADCs to produce data-collection mechanisms and a database for the UDS, implementing it in September 2005. A new version of the UDS is currently under discussion. The UDS, which collects prospective and longitudinal clinical data, has grown in size to include more than 29,000 subjects as of September 2013. The data are open to both ADC and non-ADC researchers and have resulted in more than 260 publications to date. Neuropathology data are available on more than 13,000 subjects; most of the NP data are from subjects in the MDS, but the contribution of the UDS continues to grow, with NP data now available on more than 2,600 subjects that had been followed longitudinally in the UDS. The NACC database now stands as one of the largest and most comprehensive databases of its type in the world.