Validity of the Test of Infant Motor Performance for discriminating among infants with varying risk for poor motor outcome

Objective: The objective was to assess the ability of the Test of Infant Mo tor Performance (TIMP) to discriminate among infants with varying degrees o f risk for motor developmental morbidity on the basis or perinatal medical complications. Study design: Ninety-eight infants were tested weekly with the TIMP until 4 months of age. Comparisons were made among 5 groups of infants: (1) term i nfants without significant medical problems (low risk); (2) infants born pr ematurely with no significant medical problems (medium risk); (3) infants b orn at < 30 weeks' gestational age or with birth weight < 1500 g (high risk ); (4) infants with chronic lung disease (high risk); and (5) infants with brain insults (high risk). A random-effects growth curve analysis assessed differences between the groups in slope and level of development across tim e. Results: Infants in the low- and medium-risk groups did not differ from eac h other but were significantly better performers than infants in the highri sk groups. Infants with brain insults performed significantly less well tha n all other infants, both in absolute level of performance and in developme ntal slope across time. Performance by black infants averaged 2 points high er than that of other infants. Conclusions: The TIMP can discriminate among infants with differing risks f or motor developmental delay.