WAIS-IV Seven-Subtest Short Form: Validity and Clinical Use in ă Schizophrenia
Résumé
Objective: This study assesses the psychometric properties of Ward's ă seven-subtest short form (SF) for WAIS-IV in a sample of adults with ă schizophrenia (SZ) and schizoaffective disorder. ă Method: Seventy patients diagnosed with schizophrenia or schizoaffective ă disorder were administered the full version of the WAIS-IV. Four ă different versions of the Ward's SF were then calculated. The subtests ă used were: Similarities, Digit Span, Arithmetic, Information, Coding, ă Picture Completion, and Block Design (BD version) or Matrix Reasoning ă (MR version). Prorated and regression-based formulae were assessed for ă each version. ă Results: The actual and estimated factorial indexes reflected the ă typical pattern observed in schizophrenia. The four SFs correlated ă significantly with their full-version counterparts, but the Perceptual ă Reasoning Index (PRI) correlated below the acceptance threshold for all ă four versions. The regression-derived estimates showed larger ă differences compared to the full form. The four forms revealed ă comparable but generally low clinical category agreement rates for ă factor indexes. All SFs showed an acceptable reliability, but they were ă not correlated with clinical outcomes. ă Conclusions: The WAIS-IV SF offers a good estimate of WAIS-IV ă intelligence quotient, which is consistent with previous results. ă Although the overall scores are comparable between the four versions, ă the prorated forms provided a better estimation of almost all indexes. ă MR can be used as an alternative for BD without substantially changing ă the psychometric properties of the SF. However, we recommend a cautious ă use of these abbreviated forms when it is necessary to estimate the ă factor index scores, especially PRI, and Processing Speed Index.