Abstract This study was designed as a multi-site field experiment to test the efficacy of hospital and home visit interventions to improve interaction between mothers and preterm infants. Hospital intervention consisted of State Modulation (SM) treatment, which focused on teaching mothers to read the behavioral cues and modulate the states of consciousness of preterm infants during feedings. Home visit intervention was a field-tested program, Nursing Systems for Effective Parenting-Preterm (NSTEPP), implemented during the first five months after the infant's hospital discharge. A hospital program on car seats (CS) and standard public health nursing home visits (PHN) served as comparison treatments. The sample consisted of 327 mothers and their preterm infants who were less than 36 weeks of gestational age at hospital discharge. Mothers were randomly assigned to intervention groups on the basis of their education. High education (HE) was ≤ 13 years of education, while low education (LE) was ≥ 12 years of education. HE mothers were only assigned to hospital programs, while LE mothers were assigned to combinations of hospital and home visit programs. Evaluations were conducted at 40 weeks conceptual age (expected date of birth), at 46 weeks conceptual age (1.5-months-corrected age), and 60 weeks conceptual age (5-months-corrected age).
Comparisons were made within each educational group. For HE groups, SM infants gave significantly more clear cues during observations of feeding interactions at 1.5-months-corrected age and teaching interactions at 5-months-corrected age than infants in the CS group. During the teaching interaction, well-educated SM mothers provided significantly more social-emotional and cognitive stimulation than CS mothers. For LE groups, infants in the SM group combined with either PHN or NSTEP-P exhibited significantly more responsive behavior during feeding observations than those infants in the CS/PHN group at 1.5-months-corrected age. LE mothers in the SM/NSTEP-P group demonstrated more sensitivity and more stimulation during teaching interactions at 5-months-corrected age than mothers in the SM/PHN or CS/PHN groups. Findings suggest that State Modulation treatment is effective in influencing positive social interaction of infants regardless of the level of maternal education. State modulation treatment combined with NSTEP-P is most effective in improving the social interaction between preterm infants and mothers with limited formal education. Such treatment-specific