The Clinical Usefulness of the Rivermead Perceptual Assessment Battery: Statistical Considerations

The Rivermead Perceptual Assessment Battery (RPAB) is designed to assess visual perception deficits in people suffering from stroke and head Injury. It Is one of the few standardised perceptual assessments specifically developed for occupational therapists. This article examines some aspects of the statistical background of the RPAB. The RPAB authors have reported limited statistical data, which Is Insufficient to understand fully the clinical usefulness of this assessment tool.

Reliability and validity are examined and the implications of test results are discussed. The true score range for patients on each subtest is calculated, as well as the amount of change over time required before clinicians can be confident that such change represents a real improvement or decline In the patient's ability. Further, the discriminative power of each subtest is examined, as are the criteria for determining the presence and type of perceptual deficit. These statistical analyses were based on the data reported in the test's manual, as well as from patients assessed at The Prince Henry Hospital, Sydney, over a 2-year period.