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A performance-based measure for assessing executive functions (EF) is useful to understand patients’ real life performance of EF. This study aimed to develop a performance-based measure of executive functions (PEF) based on the Lezak model and to examine psychometric properties (i.e., unidimensionality and reliability) of the PEF using Rasch analysis in patients with schizophrenia. We developed the PEF in three phases: (1) designing the preliminary version of PEF; (2) consultation with experts, cognitive interviews with patients, and pilot tests on patients to revise the preliminary PEF; (3) establishment of the final version of the PEF and examination of unidimensionality and Rasch reliability. Two hundred patients were assessed using the revised PEF. After deleting items which did not satisfy the Rasch model’s expectations, the final version of the PEF contained 1 practice item and 13 test items for assessing the four domains of EF (i.e., volition, planning, purposive action, and effective performance). For unidimensional and multidimensional Rasch analyses, the 4 domains showed good reliability (i.e., 0.77–0.85 and 0.87–0.90, respectively). Our results showed that the PEF had satisfactory unidimensionality and Rasch reliability. Therefore, clinicians and researchers could use the PEF to assess the four domains of EF in patients with schizophrenia.

BackgroundNo studies have compared the 2-factor structures of Wong’s and Post’s versions of the short-form Stroke-Specific Quality of Life (i.e., 12-item SSQOL) scale. This study compared the construct validity of 2 short-forms of the 12-item-SSQOL (not the 12-domain-SSQOL).MethodsData were obtained from a previous validation study of the original 49-item SSQOL in 263 patients. Construct validity was tested by confirmatory factor analysis (CFA) to examine whether the two-factor structure, including psychosocial and physical domains, was supported in both versions. The CFA tested the data-model fit by indices: chi-square χ2/df ratio, root mean square error of approximation (RMSEA), comparative fit index (CFI), nonnormative fit index (NNFI), standard root mean square residual (SRMR), and parsimony normed fit index (PNFI). Item factor loadings (cutoffs: .50) were examined. Model fit was compared using Akaike information criterion (AIC) and consistent AIC (i.e., CAIC) values.ResultsAll model fit indices for Post’s version fell within expected ranges: χ2/df ratio = 2.02, RMSEA = 0.05, CFI = 0.97, NNFI = 0.97, SRMR = 0.06, and PNFI = 0.76. In the psychosocial domain, the item factor loadings ranged from 0.46 to 0.63. In the physical domain, all items (except the language and vision items) had acceptable factor loadings (0.68 to 0.88). However, in Wong’s version, none of the model indices met the criteria for good fit. In model fit comparisons, Post’s version had smaller AIC and CAIC values than did Wong’s version.ConclusionsAll fit indices supported Post’s version, but not Wong’s version. The construct validity of Post’s version with a 2-factor structure was confirmed, and this version of the 12-item SSQOL is recommended.