The Zurich Maxi Mental Status Inventory (ZuMAX): Test-Retest Reliability and Discriminant Validity in Stroke Survivors

Objective: To examine discriminant validity and test-retest reliability of the Zurich maxi mental status inventory (ZuMAX) in patients with stroke. Background: The ZuMAX is a novel domain-specific cognitive assessment tool to screen for disturbances in neuropsychological function. The test can be used in stroke rehabilitation to estimate severity of cognitive impairment. Because evidence for validity and reliability is lacking, the tool's clinical use is limited. Methods: We administered the ZuMAX in a test-retest design to 33 community-dwelling stroke survivors, and once to 35 healthy controls matched for age and sex. Results: We found significant group differences in subscores for the cognitive domains of executive functions and language as well as total score (P=0.001 to 0.004); we did not find group differences for the domains of praxia (defined as the ability to perform purposeful actions), visual perception and construction, or learning and memory. Test-retest reliability of the total score was good (intraclass correlation coefficient = 0.81), with the individual domain subscores ranging from poor to fair (0.59 to 0.79). The ZuMAX could detect changes in patients with low smallest detectable differences in executive functions, language, and praxia (0.05 to 1.49) and total score (0.09). Conclusion: The ZuMAX has moderate to good test-retest reliability. Furthermore, the tool might discriminate between healthy persons and chronic stroke survivors on three of five subscales. The ZuMAX shows promise in measuring neuropsychological disturbances in stroke survivors; however, further trials are required with larger samples.