Comparison of the sensory integrative function of South African infants to normative data on two standardised tests

BACKGROUND: The Dunn Infant Toddler Sensory Profile and DeGangi's Test of Sensory Functions in Infants are two standardised tests that are widely used by South African therapists to assess sensory integrative function in infants. There is, however, no research available on the validation of these standardised tests for a South African population. This research determined whether the normative data established in the United States of America on the Infant Toddler Sensory Profile and the Test of Sensory Functions in Infants were valid for use with South African infants between the ages of 7 and 18 months. METHODOLOGY: A quantitative cross-sectional, descriptive, correlation study design was used to investigate the equivalence between the normative data from the United States of America and a sample of typically developing South African infants. FINDINGS: The results indicated that the mean scores for the South African sample in five of the six processing sections of the Infant Toddler Sensory Profile and all quadrant scores, were in the lower range of the typical performance according to the normative data of the United States of America. On the Oral Processing Section and the Sensation-Seeking Quadrant, test results should be interpreted with caution due to the medium effect size indicating clinical differences to the reported norms. A higher percentage of South African infants had a clear definite difference "more than others" score compared to normative data from the United States of America. On the Test of Sensory Functions in Infants, the means of the frequency distribution for deficient, at risk, and typical for all five sections and the Total Test Scores for the South African sample were significantly different from the normative data of the United States of America and the mean scores fell into the lower range or below the range for the typical performance reported in the test manual. CONCLUSIONS AND RECOMMENDATIONS: The Infant Toddler Sensory Profile can be used without substantial re-norming based on the findings related to this South African sample. Due to significant differences in scores on the Test of Sensory Functions in Infants, the first author questions the use of the test and recommends further research on South African infants with a larger population group. However, it should be noted that this study had a small sample size and therefore the results should be interpreted with caution and cannot be generalised.