Purpose: The Motor-Free Visual Perception Test-4 (MVPT-4) is a multidimensional measure of visual perception with five subscales (visual discrimination, figure-ground, visual memory, spatial relationships, and visual closure). The purpose of this study was to examine practice effect and test-retest reliability of the MVPT-4 over four serial assessments in patients with stroke.
Methods: We recruited outpatients with stroke with age above 20 years, able to follow instructions, and able to sign informed consent. We excluded patients who had visual neglect and visual deficits (e.g., diplopia, cataract, and glaucoma). Sixty patients completed the MVPT-4 four times, one week apart. Cumulative and plateau phases of the practice effect were evaluated across four assessments. Test-retest reliability was examined using the intraclass correlation coefficient (ICC).
Results: The MVPT-4 scale and five subscales showed cumulative phases. Only the spatial relationships subscale may have reached a plateau phase at the second assessment. The ICC values of the MVPT-4 scale and five subscales were 0.48-0.87. The minimum and maximum values of the 90% confidence interval (CI) of reliable change index modified for practice (RCIp) were: MVPT-4 scale [-5.0, 7.7]; visual discrimination [-1.7, 2.1]; figure-ground [-2.0, 2.6]; visual memory [-2.6, 3.2]; spatial relationships [-2.3, 3.0]; and visual closure [-2.5, 2.8].
Conclusions: The MVPT-4 scale and five subscales appeared increasing trends of practice effects and moderate to excellent test-retest reliability in patients with stroke. The minimum and maximum values of the 90% CI RCIp for the spatial relationships subscale which may have reached a plateau phase that can help clinicians and researchers to ascertain whether the real score change is occurred for an individual patient.Implications for rehabilitationThree multilevel regression models were conducted to evaluate the plateau phase of the practice effect over four assessments.The patterns of practice effects and evidences of test-retest reliability of the MVPT-4 scale and five subscales over four serial assessments can be used to follow the progress of patients with stroke.The minimum and maximum values of the 90% CI RCIp of the MVPT-4 can assist clinicians and researchers to explain score changes for an individual patient with stroke.
Keywords: Visual perception; practice effect; reliability; reliable change index modified for practice; stroke.