With NACC’s query system, you can determine quickly whether NACC is likely to have subjects you are looking for in numbers sufficient to address your research question. (Also, some research questions about available data can be answered quickly by the NACC data summary tables.) Please note that query results should be used only as rough, preliminary numbers. For publication purposes, please make a custom data request
Many data elements used in NACC’s direct query system are derived or calculated variables that describe a combination of data elements taken directly from the UDS forms (e.g., “Age at initial visit” is derived from the subject’s birth year and month and the date of the initial UDS visit). The guide to the query system describes the sources for these data elements.
Web-based query system
CAUTION: The de-identified MRI DICOM files were voluntarily submitted to NACC by the Alzheimer’s Disease Research Centers (ADRC). DICOM files submitted do not have a standard, common format, thus, the “metadata” in tags labels and headers will vary in position and may also contain inconsistencies or inaccuracies. Motion and coverage artifacts may occasionally be present despite ADRC efforts to avoid their inclusion. NACC has screened for and removed accidental remaining PHI missed by ADRC de-identification, however rare, undiscovered instances could potentially remain embedded in metadata. If you note such potential PHI occurrences, please report them to NACC immediately for corrective action.