The Italian version of the obsessive compulsive inventory: its psychometric properties on community and clinical samples.

The aim of the study was to evaluate psychometric properties of the Obsessive Compulsive Inventory (OCI) on Italian community and clinical samples. The Italian version of the 42-item OCI was administered to a sample of 340 individuals belonging to the general population and to 88 patients with obsessive compulsive (OCD) or other anxiety disorders. Four different internal structures of the OCI were compared through confirmatory factor analysis (CFA): the figures for the model with six factors and 18 items (OCI-R) met the best criteria for adequacy of fit. The six scales showed on average a 10% of common variance in the community sample and 8% in the clinical sample. The OCI-R subscales showed good internal consistency and temporal stability, with the exception of washing and mental neutralizing subscales which showed a strong alpha coefficient only in the OCD sample. Psychometric data for the OCI-R were insensitive to age and sex, whereas an effect of education was found. Concurrent validity was demonstrated, since the OCI-R subscales showed a pattern of specific correlations with another conceptually related self-report measure. Moreover, although the OCI-R was positively correlated with measures of depression, anxiety, and worry, the correlations were weaker than those with the other measure of OCD symptoms. The OCI-R clearly differentiated OCD patients from non-OCD anxious patients and nonclinical controls with the exception of hoarding subscale. However, the hoarding scale discriminated OCD patients who presented hoarding symptoms from OCD counterparts without such symptoms. Thus, the OCI-R proved to be a reliable and valid measure of obsessive compulsive symptoms in the Italian context.