Development of a computerized multistage testing of working memory in patients with schizophrenia

Autor: Gong-Hong Lin, 林恭宏
Rok vydání: 2018
Druh dokumentu: 學位論文 ; thesis
Popis: 106
Background and purposes: Working memory (WM) can be defined as an individual’s ability to maintain and manipulate information temporarily. WM deficit is a core syndrome of cognitive deficits for patients with schizophrenia. WM deficit may affect other syndromes of schizophrenia, functional outcomes, and quality of life. However, current frequently used WM tests have 3 limitations, including: (1) incomprehensive assessment of the WM components of the Baddeley’s multiple-component model; (2) heavy administration burden of the paper-and-pencil tests for assessors; and (3) unsound / less-examined psychometric properties. Due to these 4 limitations, researchers and clinicians cannot efficiently and accurately measure the WM deficits in patients, which hampers the efficiency and efficacy in the research and treatment on WM. To deal with the limitations of the WM tests, the first aim of this study was to develop a Computerized Multistage Testing of Working Memory (COWMEM) in patients with schizophrenia based on the Baddeley’s multiple-component model. The second aim of this study was to examine the preliminary psychometric properties of the COWMEM in patients with schizophrenia, including reliability and validity (concurrent validity, convergent validity, and known-groups validity). Methods: This study is comprised of 2 phases. Phase 1 contained 6 steps to develop the COWMEM: (1) designing the items of the COWMEM’s 6 item banks (domains): phonological loop, visuospatial sketchpad, episodic buffer, and central executive’s 3 types of attentional controls (focused attention, switching attention, and divided attention); (2) examining the content validity; (3) establishing the administration platform of the item banks; (4) administering the item banks in patients with schizophrenia; (5) validating the item banks: deleting the items which did not fit the unidimenal Rasch model in each item bank; and (6) selecting items from the item banks to establich the COWMEM. In Phase 2, the data collected in Phase 1 were used to validate the psychometric properties of the COWMEM. To examine the reliability of the COWMEM, individual patient’s Rasch reliability and the average Rasch reliability of the patients were calculated. To validate the concurrent validity, Pearson’s r was calculated to examine the correlations between the 6 domain scores of the COWMEM and the scores of the corresponding external criteria [Spatial Span-backward, Digit Span-backward, California Verbal Learning Test-10 minutes delayed recall, Test of Everyday Attention (TEA)-Elevator counting, TEA-Visual elevator, and TEA-Telephone search dual task]. To validate the convergent validity, the correlations among the COWMEM’s 6 domain scores were examined using Pearson’s r. To validate the known-groups validity, the patients were divided into 2 groups (good or poor cognition) according to the patients’ scores of the Montreal Cognitive Assessment (≥ 26 or ≤ 25). Next, in each domain of the COWMEM, the extent of difference of the mean domain scores between the 2 groups was examined using effect size (Cohen’s d). Results: In Phase 1, the item banks of the COWMEM were validated through 3 rounds of examination for content validity, administered on 149 patients with schizophrenia, and 5 items which did not fit the Rasch model were deleted. Finally, the COWMEM contained 6 routing items and 2 item sets (difficult or easy; 15 items in each item set) in each of the 6 domains (a total of 186 items). In the administration of the COWMEM, each patient had to complete the 6 routing items and 1 item set (which are chosen according to the patient’s performance on the routing items) in each of the 6 domains (a total of 96 items). In Phase 2, the results of the reliability indicate that the COWMEM has acceptable individual reliability (52.0%~100.0% of patients had Rasch reliability ≥ 0.70) and average reliability (0.70~0.86 across the 6 domains). The results of the concurrent validity indicate that the COWMEM has acceptable concurrent validity in the 3 domains (phonological loop, visuospatial sketchpad, and episodic buffer; Pearson’s rs = 0.50~0.52) but poor concurrent valditiy in the other 3 domains (central executive’s 3 types of attentional controls; Pearson’s rs = 0.21~0.22). The results of the convergent validity indicate that the COWMEM has good convergent validity (Pearson’s rs = 0.33~0.87). The results of the known-groups validity indicate that the COWMEM has moderate-to-good known-groups validity (Cohen’s ds = 0.72~1.06). Conclusion: The COWMEM may be the first computerized WM test for comprehensively assessing 6 domains of WM. The preliminary examination of psychometric properties indicate that the COWMEM has acceptable reliability, good convergent validity, moderate-to-good known-groups validity. Regarding the concurrent validity, the 3 domain scores (phonological loop, visuospatial sketchpad, and episodic buffer) of the COWMEM have acceptable concurrent validity, but the concurrent validity of the other 3 domain scores (central executive’s 3 types of attentional controls) are unclear. The COWMEM can be used to compare the scores of the 6 WM domains among groups of patients with schizophrenia (e.g., control vs. treatment group in research or comparisons between groups of patients with different severities or stages in clinical settings).
Databáze: Networked Digital Library of Theses & Dissertations
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