A randomized controlled trial of clinic-based and home-based interventions in comparison with usual care for preterm infants: Effects and mediators

https://doi.org/10.1016/j.ridd.2014.06.009Get rights and content

Highlights

  • Interventions enhanced the cognition, motor, and behavior in preterm infants.

  • Early improved dyadic interaction may mediate the effects on infants’ cognition.

  • Early improved emotional regulation may mediate the effects on infants’ behavior.

  • Findings are insightful for the design of intervention programs in preterm infants.

Abstract

This study examined the effects and mediators of a clinic-based intervention program (CBIP) and a home-based intervention program (HBIP) compared with usual care in very-low-birth-weight (VLBW) preterm infants on developmental and behavioral outcomes at 24 months of age (corrected for prematurity). In this randomized controlled trial, VLBW preterm infants received either CBIP (n = 57), HBIP (n = 63), or usual care (n = 58) from hospitalization to 12 months. At 12 months, infant emotional regulation was assessed using the toy-behind-barrier procedure and dyadic interaction was observed during free play. At 24 months, infant developmental and behavioral outcomes were assessed using the Bayley Scales of Infant and Toddler Development- 3rd edition and the Child Behavior Checklist for Ages 1.5–5, respectively. Compared with infants under usual care, the CBIP-group infants showed higher cognitive composite scores (difference, 95% confidence interval (CI) = 4.4, 0.8–7.9) and a lower rate of motor delay (odds ratio (OR), 95% CI = 0.29, 0.08–0.99); the HBIP-group infants had lower sleep problem scores (difference, 95% CI = −1.4, −2.5 to −0.3) and a lower rate of internalizing problems at 24 months (OR, 95% CI = 0.51, 0.28–0.93) (all p < .05). The CBIP's effect on cognitive outcome was attenuated when maternal or dyadic interactive behavior was considered; whereas the HBIP's effect on sleep and internalizing behavior was attenuated when duration of orientation to a toy or object was considered. In conclusions, interventions enhanced the cognitive, motor, and behavioral outcomes of VLBW preterm infants. The effects on cognitive and behavioral outcomes might be mediated by early-improved mother–infant interaction and infant emotional regulation, respectively.

Introduction

Preterm births with very-low-birth-weight (VLBW; birth weight < 1500 g) exert unfavorable effects on not only maternal psychological wellness (Saigal & Doyle, 2008) and mother–infant interaction (Bozzette, 2007) but also child developmental outcomes (Aarnoudse-Moens et al., 2009, Saigal and Doyle, 2008). In Western countries, various interventions have been developed for preterm infants that yielded small motor benefits in early infancy and moderate cognitive benefits from infancy to preschool age (Orton et al., 2009, Spittle et al., 2012, Vanderveen et al., 2009), but inconclusive effects on behavioral outcome (Blair, 2002, Brooks-Gunn et al., 1993, Kaaresen et al., 2008, Kleberg et al., 2000, Koldewijn et al., 2010, Koldewijn et al., 2005, Koldewijn et al., 2009, Nordhov et al., 2012, Spencer-Smith et al., 2012, Spittle et al., 2010, Westrup et al., 2004). The investigation in Eastern societies has been limited to only one study in China, which showed cognitive benefits (Bao, Sun, Wei, & Coo, 1999). Given substantial variations in health care systems and family structures among societies, the effect of intervention programs needs to be investigated in relevant cultural contexts.

Despite documented effectiveness, the social and developmental pathways underlying the interventions remain unclear. Behavioral interchanges between an infant and his/her caregiver have been proposed as a vehicle for the development of cognitive, language, psychomotor, and socio-emotional functions (Browne, 2003, Dunn et al., 2006, Geva and Feldman, 2008, Ramey et al., 1984). Early responsive parenting and focused infant attention during dyadic interaction have been found to predict later favorable cognitive, language, and behavioral outcomes in both term and preterm infants (Forcada-Guex et al., 2006, Lawson and Ruff, 2004, Schmidt and Lawson, 2002, Smith et al., 2006). One study of preterm infants reported that improvement in maternal responsiveness at 30 months of age mediated an intervention's effect on cognitive outcomes at 36 months of age (Mahoney, Boyce, Fewell, Spiker, & Wheeden, 1998). In addition, emotional regulation has been proposed as the antecedent variable of behavioral outcomes (Geva and Feldman, 2008, Mahoney et al., 1998). Inadequate stress regulatory behavior in the first year of life was found to predict behavioral problems at 5 years of age in preterm infants (Feldman, 2009). Partnership with a parent and advanced attention control for emotional regulation, which form the foundation of subsequent development (Carpenter et al., 1998, Lowe et al., 2010) and behavior (Bell and Deater-Deckard, 2007, Calkins and Fox, 2002), are developed in infants at 12 months of age. This time period therefore provides a critical window to investigate the social and developmental pathways underlying effective interventions.

Early intervention for preterm infants in Taiwan has been limited to in-hospital developmental care at certain medical centers. To replicate the benefits of home visits from Western experiences (Brooks-Gunn et al., 1993, Koldewijn et al., 2010, Newnham et al., 2009) and to adapt intervention programs to the high accessibility of clinic visits for after-discharge services in Taiwan, we developed a clinic-based intervention program (CBIP) and a home-based intervention program (HBIP) for VLBW preterm infants in Taiwan from hospitalization until 12 months of age (corrected for prematurity) (Chen et al., 2013). The CBIP and HBIP contained similar child-, parent- and dyad-focused services and the interventions after discharge were respectively delivered at clinic and at home. Compared with the usual care program (UCP), these programs significantly reduced the incidence of retinopathy and feeding desaturation, and enhanced weight gain in the neonatal period (Chen et al., 2013).

This study therefore extended our research to examine the long-term effectiveness of the CBIP and HBIP in comparison with UCP on VLBW preterm infants’ developmental and behavioral outcomes at 24 months of age. Additionally, this study investigated whether mother–infant interaction and infant emotional regulation at 12 months mediated the interventions’ effects on subsequent developmental and behavioral outcomes for the infants. We expected that the CBIP and HBIP would enhance infants’ developmental and behavioral performance at 24 months of age through better mother–infant interaction and infant emotional regulation at 12 months of age.

Section snippets

Participants

This randomized controlled trial (RCT) enrolled VLBW preterm infants from three hospitals in northern Taiwan from 2006 to 2008 (Chen et al., 2013). The inclusion criteria were birth weight <1500 g, gestational age <37 weeks, admission to the study hospital within 7 days of birth, singleton birth or the first child of twins or multiples (equal contribution from each family to the data), and an absence of congenital anomalies or severe neonatal diseases (seizure, hydrocephalus,

Results

Of the 211 VLBW preterm infants enrolled in the RCT, 29 were early dropouts, and 178 remained in the study (Fig. 1). The birth and demographic characteristics of the preterm infants who ever returned for follow-up (n = 161) were similar to those of the infants who did not return (n = 17). Of those infants who returned, no characteristics differed among the three groups of preterm infants (Table 2).

Discussion

The two intervention programs appeared to yield differential effects on dyadic interaction and infant emotional regulation in VLBW preterm infants at 12 months of age. The CBIP had marginal effects for mother–infant interaction and emotional regulation, enhancing maternal and dyadic interactive behaviors and decreasing the duration of escape; whereas the HBIP was effective only for emotional regulation, decreasing the duration of orientation to a toy and increasing the duration of orientation

Limitations

The RCT design is the strength of the study. However, the homogeneity of the participants, who resided in a city with adequate medical and social resources, may limit the generalizability of our results. Additionally, the laboratory setting of the toy-behind-barrier and free-play procedures may not reflect a natural situation in daily life, although this setting allows observation of infant and maternal behaviors in a standardized way. Finally, estimation of our sample size was based on the

Conclusions

The results of this study demonstrated the effectiveness of the interventions in improving the cognitive, motor, and behavioral outcomes of Taiwanese VLBW preterm infants by 24 months of age. Furthermore, early-improved mother–infant interaction and infant emotional regulation appeared to respectively mediate the interventions’ effects on the infants’ cognitive and behavioral outcomes. Our findings provide important insights into the design of intervention programs and intriguing clues

Funding source

All phases of this study were supported by two grants from the National Health Research Institute (NHRI-EX98-9519PI, NHRI-EX102-10106PI) and a grant from the National Science Council (NSC98-2314-B-002-010-MY3) in Taiwan.

Financial disclosure

None

Conflict of interest

None

Clinical trial registration

This randomized controlled trial has been registered at www.clinicaltrials.gov (registry title: Early intervention for preterm infants; number: NCT00173108).

Acknowledgements

This study received grant support from the National Health Research Institute (NHRI-EX98-9519PI and NHRI-EX102-10106PI) and the National Science Council (NSC98-2314-B-002-010-MY3) in Taiwan. We thank the infants and their parents for participation in the study and the medical and nursing staff of the Neonatal Intensive Care Unit at National Taiwan University Hospital, MacKay Memorial Hospital, and Taipei City Hospital Branch for Women and Children for their assistance in patient recruitment and

References (51)

  • A.J. Spittle et al.

    Early emergence of behavior and social-emotional problems in very preterm infants

    Journal of the American Academy of Child and Adolescent Psychiatry

    (2009)
  • Y.T. Wu et al.

    Maternal-reported behavioral and emotional problems in Taiwanese preschool children

    Research in Developmental Disabilities

    (2012)
  • Y.T. Yu et al.

    A psychometric study of the Bayley Scales of Infant and Toddler Development- 3rd Edition for term and preterm Taiwanese infants

    Research in Developmental Disabilities

    (2013)
  • C.S. Aarnoudse-Moens et al.

    Meta-analysis of neurobehavioral outcomes in very preterm and/or very low birth weight children

    Pediatrics

    (2009)
  • T.M. Achenbach et al.

    Manual for the ASEBA preschool forms & profiles: An integrated system of multi-informant assessment

    (2000)
  • H. Als et al.

    Individualized behavioral and environmental care for the very low birth weight preterm infant at high risk for bronchopulmonary dysplasia: Neonatal intensive care unit and developmental outcome

    Pediatrics

    (1986)
  • X.L. Bao et al.

    Early intervention promotes intellectual development of premature infants: A preliminary report

    Chinese Medical Journal

    (1999)
  • R.M. Baron et al.

    The moderator-mediator variable distinction in social psychological research: Conceptual, strategic, and statistical considerations

    Journal of Personality and Social Psychology

    (1986)
  • N. Bayley

    Bayley Scales of Infant and Toddler Development

    (2006)
  • M.A. Bell et al.

    Biological systems and the development of self-regulation: Integrating behavior, genetics, and psychophysiology

    Journal of Developmental and Behavioral Pediatrics

    (2007)
  • K.M. Benzies et al.

    Key components of early intervention programs for preterm infants and their parents: A systematic review and meta-analysis

    BMC Pregnancy and Childbirth

    (2013)
  • C. Blair

    Early intervention for low birth weight, preterm infants: The role of negative emotionality in the specification of effects

    Development and Psychopathology

    (2002)
  • J. Brooks-Gunn et al.

    Enhancing the development of low-birthweight, premature infants: Changes in cognition and behavior over the first three years

    Child Development

    (1993)
  • J.V. Browne

    New perspectives on premature infants and their parents

    Zero to Three

    (2003)
  • S.D. Calkins et al.

    Self-regulatory processes in early personality development: A multilevel approach to the study of childhood social withdrawal and aggression

    Development and Psychopathology

    (2002)
  • Cited by (34)

    • Effects of early interventions focused on the family in the development of children born preterm and/or at social risk: a meta-analysis

      2020, Jornal de Pediatria
      Citation Excerpt :

      In one of the studies,36 two groups underwent the same early intervention focused on the family, one at home and the other at the outpatient clinic, using the Bayley III evaluation tool. All the interventions showed previously mentioned characteristics, based mainly on the synchronous-active theory.20,32–37 The control groups received the usual service care, but without the early intervention focused on the family.

    View all citing articles on Scopus
    View full text