Predictive Value of Test of Infant Motor Performance for Infants based on Correlation between TIMP and Bayley Scales of Infant Development

OBJECTIVE To assess the relationship of scores on the test of infant motor performance (TIMP), with those on the Bayley scales of infant development (BSID), and to investigate the sensitivity and specificity of TIMP and the optimal cut-off value of TIMP scores using ROC analysis. METHOD Seventy-six preterm and term infants were recruited from neonatal intensive care units. Subjects were tested with the TIMP at their initial visit and after 6 months, they were tested by using BSID. RESULTS In the reliability study, TIMP scores showed highly significant correlation with the Bayley physical developmental index (BPDI) (p=0.001) and Bayley mental developmental index (BMDI) (p=0.017). Receiver operator characteristics (ROC) curve analysis was performed to evaluate the TIMP test for screening infant motor development. ROC analysis showed an area under the curve (AUC) of 0.825 (p=0.005) in BPDI and 0.992 (p=0.014) in BMDI, indicating an excellent classification performance of the model. The optimal cut-off value where a sensitivity of 86%, and specificity of 68% were achieved with the TIMP was 1.50 (between average and below average) in BPDI and where a sensitivity of 100%, and specificity of 66% were achieved with the TIMP was 1.50 in BMDI. CONCLUSION Our results indicate that the TIMP provides a reliable and valid measurement that can be used for the evaluation of motor function in preterm and term infants. TIMP was highly sensitive and specific with the follow-up examination of BSID. Therefore it can be used as a reliable screening tool for neonates and infants aged <4 months.