AGRE provides the following three computer-scored affected status categories, which are based on the Autism Diagnostic Interview-Revised (ADI-R) domain scores:
These categories are not “diagnoses” per se but are offered to further categorize subjects based on the ADI-R, given that the ADI-R provides a validated algorithm only for the diagnosis of autism. To meet the criteria for autism on the ADI-R, subjects must meet the required cutoff scores on the domains of social interaction, communication, repetitive behaviors, and age of onset (http://research.agre.org/program/aboutadi.cfm).
It should be understood that while AGRE uses ADI-R data to derive these affected status categories, the authors of the ADI-R (Rutter, Lord, LeCouteur, 1997) have not provided validated algorithms to identify individuals on the broader autism spectrum (e.g., PDD-NOS, Asperger's Disorder, or other broader phenotypes). As a result, many research groups utilize the ADI-R in combination with other diagnostic instruments, such as the ADOS (http://research.agre.org/program/aboutados.cfm), to derive clinical diagnoses of PDD-NOS and Asperger's.
We provide these affected status categories not to limit analyses or impose them upon researchers, but to facilitate analysis by those who may not be comfortable interpreting the ADI-R data to formulate their own diagnoses. In recognizing that there are many different ways to approach diagnostic algorithms, AGRE has provided the full ADI-R data so that individual investigators can apply their own criteria. In addition, we have provided ADOS scores and other clinical data for many of our subjects, so that researchers may consider these data when clarifying diagnoses along the autism spectrum.
Because AGRE understands that some researchers prefer to have affected status categories pre-assigned, AGRE has provided such classifications for the AGRE sample. In addition to providing strict autism diagnoses, AGRE has assigned the affected status categories of NQA and Broad Spectrum so that researchers can easily identify family members on the spectrum who show potential value for inclusion in genetic or behavioral studies of autism. Please note that these latter two categories are not DSM-IV diagnoses, but rather, diagnostic classifications that would require further clinical review in order to establish a final clinical diagnosis.
The following is a summary of AGRE's current affected status categories:
PLEASE NOTE: Because a number of the subjects included in the Broad Spectrum category have relatively low domain scores and may not meet the DSM-IV diagnostic criteria for an autism spectrum disorder, we recommend that researchers take a close look at the domain scores of each subject (along with the ADOS results, if available), before deciding whether or not to include them in their subject pool.