Meta-analysis of physiological outcomes of hospital-based infant intervention programs.

A meta-analysis of 37 studies on the effects of an intervention program on physiological development of the premature infant was conducted using multidisciplinary research reported since 1979. Two homogeneous populations based on mean infant birth weight were found in which infant stimulation programs were shown to be effective in enhancing physiological development (Group I: mean birth weight = 1,260 g, mean combined effect size = 1.54, SD = 0.54, 95% confidence interval = 1.22-1.86; Group II: mean birth weight = 1,524 g, mean combined ES = 0.51, SD = 0.30, 95% confidence interval = 0.39-0.63). The robustness of Group I was tentative based on the lack of small sample-small effect nonsignificant result studies discovered in the funnel plot. Group II results (based upon 1,306 infants) are a stronger indication that, in general, infants with birth weights greater than 1,500 g are positively affected by the initiation of a stimulation program during hospitalization.