Electronic error and alert checks

The NACC database of UDS subjects is made up of three data sets:

All told, the NACC database comprises more than 1,400 variables, each with its own coding requirements and allowable ranges. To help ensure the quality of new data being entered into the NACC database, NACC sets electronic error and alert checks that require ADCs to correct or verify questionable values before the data are accepted.

ERROR CHECKS require that ADCs change the data value to something in the allowable range before the subject's visit packet can enter the current database and be used for research. Examples of UDS error checks:

ALERT CHECKS require that ADCs either correct or verify the data value before the subject's visit packet can enter the database. Examples of alert checks:

Please contact us for more information about NACC’s QA/QC efforts.