Diagnosis of Intellectual Disability: comparison between clinical criteria and automatized procedures

In a previous work, published in this Journal (n.10/2), we outlined the utility to find shared criteria for diagnosing the levels of Intellectual Disability / Mental Retardation. We presented a computerized algorithm based on the predefined and standardized integration of scores derived from intellectual and adaptive tests. In this paper we will report the results of the comparative analysis between the commonly used clinical diagnoses and those derived from the automatized procedure, applied to the same cases. The study was conducted on a sample of 100 diagnoses, regarding different levels of Mental Retardation (n=56), Borderline Intellective Functioning (BIF, n=25), and cases without disability (n=19). The comparison of the two modality of diagnosis was performed through factorial analysis of correspondences. The analysis showed that the clinical diagnosis an that based on the computerized algorithm agree with respect to the principal dimensions explaining the evaluation criteria. The overall concordance is 68%, with higher peak for the normal subjects and lower for the BIF, resulting the more complex diagnosis. The main differences were object of an in-depth analysis, at a qualitative level, examining the profiles of discrepant cases, regarding always adjacent levels. It was further verified how much the diagnosis was related to the only value of IQ, obtaining a correlation (Spearman’s rs) of .44 with the clinical diagnosis and .47 with the computerized one. In conclusion, the standardized algorithm applied by the software supplies a * Received: 31 July 2009, Revised: 20 October 2009, Accepted: 20 October 2009. © 2009 Associazione Oasi Maria SS. IRCCS / Città Aperta Edizioni 1 University of Catania and Enna ‘Kore’, Italy, e-mail: [email protected] 2 IRCCS ‘Oasi’, Troina, Italy, e-mail: [email protected] 151 Life Span and Disability XII, 2 (2009), 151-159 Diagnosis of Intellectual Disability: comparison between clinical criteria and automatized procedures Santo Di Nuovo1 & Serafino Buono2 diagnosis largely overlapping with that based on the clinical evaluation, but with differences justifying the comparative use of the different approaches.