Construct and ecological validity of the Occupational Therapy Adult Perceptual Screening Test (OT-APST)

This paper reports on the construct validity (scale design and convergent validity) and ecological validity of the Occupational Therapy Adult Perceptual Screening Test (OT-APST). The performance of 208 participants following stroke on the OT-APST and a reference tool (either the Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) or the LOTCA-Geriatric version (LOTCA-G)) was compared. The OT-APST performance of the stroke sample was compared with a healthy normative sample (n = 356). The relationship between the OT-APST performance and the Functional Independence Measure (FIM) score of the participants following stroke was also examined. Factor analysis and internal consistency results supported the scale design of the OT-APST. Significant correlations between the performance of the participants following stroke on the OT-APST and the reference tool supported the convergent validity of the OT-APST. The ability of the OT-APST to separate the two participant groups provided further evidence of its construct validity. Significant correlations between OT-APST and FIM scores supported the ecological validity of this tool. This study shows that the OT-APST is an ecologically valid tool with demonstrated construct validity in the assessment of visual perception.

The Reliability of Performance of Healthy Adults on Three Visual Perception Tests

Problems with visual perceptual skills have been shown to have a negative impact on the daily living skills of individuals and are, therefore, commonly assessed by occupational therapists. The purpose of this study was to examine two types of reliability (internal consistency and test-retest reliability) of three newly revised or developed adult visual perception tests. The participants were 50 healthy adults, aged 18 to 55 years, from Melbourne, Victoria, Australia. The participants completed the Developmental Test of Visual Perception — Adolescent and Adult (DTVP-A), the Motor-Free Visual Perception Test — Third Edition (MVPT-3) and the Test of Visual Perceptual Skills (non-motor) – Third Edition (TVPS-3). Internal consistency was examined using Cronbach's alpha calculations and test-retest reliability was analysed using Spearman rho non-parametric correlation coefficients.

The results indicated that the DTVP-A, the MVPT-3 and the TVPS-3 had total scale internal consistency correlation scores of 0.60 or higher (0.60, 0.69 and 0.63 respectively). The majority of the subscales of each test had lower correlation coefficients than the overall scores (ranging from 0.22 to 0.49). For the DTVP-A, MVPT-3 and TVPS-3 total scale scores, the test-retest reliability correlation coefficients were statistically significant (rho = 0.46, p<0.05; rho = 0.62, p<0.01; and rho = 0.59, p<0.01, respectively). Overall, the three visual perceptual tests exhibited low to moderate levels of internal consistency and test-retest reliability.