RESUMEN
Importance: Preterm children are at risk for neurodevelopment impairments. Objective: To evaluate the effect of a music therapy (MT) intervention (parent-led, infant-directed singing) for premature children during the neonatal intensive care unit (NICU) stay and/or after hospital discharge on language development at 24 months' corrected age (CA). Design, Setting, and Participants: This predefined secondary analysis followed participants in the LongSTEP (Longitudinal Study of Music Therapy's Effectiveness for Premature Infants and Their Caregivers) randomized clinical trial, which was conducted from August 2018 to April 2022 in 8 NICUs across 5 countries (Argentina, Colombia, Israel, Norway, and Poland) and included clinic follow-up visits and extended interventions after hospital discharge. Intervention: Participants were children born preterm (<35 weeks' gestation) and their parents. Participants were randomized at enrollment to MT with standard care (SC) or SC alone; they were randomized to MT or SC again at discharge. The MT was parent-led, infant-directed singing tailored to infant responses and supported by a music therapist and was provided 3 times weekly in the NICU and/or in 7 sessions across 6 months after discharge. The SC consisted of early intervention methods of medical, nursing, and social services, without MT. Main Outcome and Measures: Primary outcome was language development, as measured by the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III) language composite score, with the remaining BSID-III composite and subscale scores as the secondary outcomes. Group differences in treatment effects were assessed using linear mixed-effects models using all available data. Results: Of 206 participants (103 female infants [50%]; mean [SD] GA, 30.5 [2.7] weeks), 51 were randomized to MT and 53 to SC at enrollment; at discharge, 52 were randomized to MT and 50 to SC. A total of 112 (54%) were retained at the 24 months' CA follow-up. Most participants (79 [70%] to 93 [83%]) had BSID-III scores in the normal range (≥85). Mean differences for the language composite score were -2.36 (95% CI, -12.60 to 7.88; P = .65) for the MT at NICU with postdischarge SC group, 2.65 (95% CI, -7.94 to 13.23; P = .62) for the SC at NICU and postdischarge MT group, and -3.77 (95% CI, -13.97 to 6.43; P = .47) for the MT group at both NICU and postdischarge. There were no significant effects for cognitive or motor development. Conclusions and Relevance: This secondary analysis did not confirm an effect of parent-led, infant-directed singing on neurodevelopment in preterm children at 24 months' CA; wide CIs suggest, however, that potential effects cannot be excluded. Future research should determine the MT approaches, implementation time, and duration that are effective in targeting children at risk for neurodevelopmental impairments and introducing broader measurements for changes in brain development. Trial Registration: ClinicalTrials.gov Identifier: NCT03564184.