Ontario Society of Occupational Therapists (OSOT) Perceptual Evaluation


Ontario Society of Occupational Therapists (OSOT) Perceptual

  What does the tool measure? Perceptual impairment in adults (Sensation, Scanning, Apraxia, Body awareness, Spatial relations, Visual agnosia).
  What types of clients can the tool be used for? Patients who have experienced brain damage caused by traumatic brain injury or stroke.
  Is this a screening or assessment tool? Assessment
Time to administer The revised OSOT takes approximately 90 minutes to complete. There is no information published regarding the time it takes to complete the original OSOT.
  Versions Original OSOT (consists of 28 subtests); Revised OSOT (consists of 18 subtests).
Other Languages English and French
Measurement Properties
  Reliability – Only 1 study has examined the internal consistency.
Only 1 study has examined the internal consistency of the revised OSOT and reported excellent internal consistency.
– No studies have examined the test-retest reliability of the OSOT.
– One study examined the inter-rater reliability of the original OSOT and reported very high agreement (93.1%) across items for all subjects.
  Validity Construct: Known groups. Both the original OSOT and the revised OSOT have been shown to discriminate between patients with acquired brain injury and healthy controls.
Concurrent. One study reported that the revised OSOT correlated adequately with the Physical Self-Maintenance Scale (PSMS), the Instrumental Activities of Daily Living Scale, and with the Mini-Mental State Evaluation (MMSE).
  Does the tool detect change in patients? No evidence.
  Acceptability A proxy respondent is not appropriate for this performance-based measure. The OSOT has not been examined for use for patients with aphasia. An alternative test is the Motor-Free Visual Perception Test, which can sometimes be used to examine the presence of visual perception impairments in patients with expressive aphasia if they are able to understand simple verbal or non-verbal instructions and the various subscale requirements.
Feasibility The OSOT is a lengthy measure to administer and requires an adequate understanding of the test procedures and instructions on the part of the examiner. A number of items are required as equipment for the OSOT, however all items are readily available. The OSOT is simple to score and uses a 5-point Likert scale for each of the subtests. A breakdown of the total score is provided and each interval corresponds to a degree of severity of the global perceptual impairment (e.g. original OSOT: 80 or below represents severe impairment; revised OSOT: 40 or below represents severe impairment).
How to obtain the tool? The OSOT is no longer available from the publisher: Nelson, A Thomson Company, 1120 Birchmount Road, Toronto, Ontario M1K 5G4, Canada
E-mail: inquire@nelson.com