Colditz PB, Boyd RN, Winter L, Pritchard M, Gray PH, Whittingham K, O’Callaghan M, Jardine L, O’Rourke P, Marquart L, Forrest K, Spry C, Sanders MR. (2019). A Randomized Trial of Baby Triple P for Preterm Infants: Child Outcomes at 2 Years of Corrected Age. J Pediatr, 210, 48-54.e42. doi:10.1016/j.jpeds.2019.01.024. PMID: 30857773
Alice Burnett, PhD
Knowledge Translation Fellow
Murdoch Children’s Research Institute
Alicia Spittle, PhD
Professor of Physiotherapy
University of Melbourne
TYPE OF INVESTIGATION
For (P) infants born very preterm (<32 weeks’ gestation), the effect of (I) Baby Triple P for Preterm Infants was compared with (C) care as usual, on (O) child behaviour and development at (T) 2 years’ corrected age.
- Design: multi-centre, randomised controlled trial
- Allocation: allocation was concealed from recruitment staff using opaque envelopes. Multiple births within a family were allocated to the same group. Allocation was stratified for site and brain injury on cranial ultrasound.
- Blinding: participants and those delivering the intervention were not blinded to group allocation; assessors of child development and parent-child interaction at 2 years were blinded to group allocation.
- Follow-up period: from the neonatal hospitalisation to 2 years’ corrected age
- Setting: 2 hospitals in Queensland, Australia
- Inclusion criteria: infants born <32 weeks and their parents were eligible
- Exclusion criteria: major congenital anomalies associated with a poor neurodevelopmental prognosis for the infant; limited parental English language skills; parental unwillingness to participate in 2-year follow-up.
- Intervention: Baby Triple-P for Preterm Infants, a parenting program adapted from the existing Triple-P Positive Parenting Program, for use with families of preterm infants. In this adaptation, the intervention comprised 4 x 2-hour sessions in the neonatal nursery, and 4 x 30-minute weekly telephone sessions after discharge home. After these initial 8 sessions, families were sent parenting tip-sheets and text messages every 3 months until the child reached 2 years’ corrected age. Families were also provided with telephone support, and were encouraged to engage with community-based Triple P programs.
- Outcomes: were measured at 2 years’ corrected age
- Primary outcome: child behaviour, measured using maternal ratings on the Infant Toddler Social & Emotional Assessment (ITSEA) and observed child behaviour during interaction with the mother, coded using the Family Observation Schedule.
- Secondary outcomes: child cognitive, language, and motor development, measured using the Bayley Scales of Infant and Toddler Development (Bayley-III) and the Communication and Symbolic Behavior Scales Developmental Profile (CSBS-DP).
- Analysis and Sample Size:
- An intention-to-treat approach was used
- It was hypothesised that the intervention would produce a standardised effect size of 0.33 on mothers’ ratings on the ITSEA. To achieve 80% power to identify this effect with a=0.05, 280 participants (140 per group) were planned.
- To account for retention of more than 85%, 323 families were enrolled in the study and randomised. 162 families (with 196 infants) were randomised to the intervention group and 161 families (188 infants) were randomised to the care-as-usual group.
- Of the 162 families in the intervention group, 148 completed at least one session of the intervention and 108 completed all 8 sessions.
- Analyses were linear mixed and logistic models, clustering for multiple births within families and adjusting for hospital site and gestational age (<28 weeks versus >=28 weeks).
- Patient follow-up:
- Primary outcome data were available for 286 families (334 children), or 87% of children in each group.
- Secondary outcome data were available for 85% of children overall.
Baseline differences: the intervention group had slightly more infants born <28 weeks than the control group. The groups were similar on other characteristics, such as abnormal cranial ultrasound, sex, and maternal pregnancy history, marital status, education, financial stress, and use of mental health services in the past 12 months.
Families with psychosocial risk factors (such as younger maternal age, unplanned pregnancy, no further education beyond secondary school, and being in financial distress) were less likely to have primary outcome data. However, the retention rates were similar between the two groups. Nearly a fifth (17%) of mothers in the intervention and 10% in the control group accessed community-based Triple P resources during the study interval.
Primary outcome: There was no effect of the intervention on maternal ratings or direct observations of child behaviour at 2 years. Mean T-scores on the ITSEA were in the normal range for both groups.
Secondary outcome: Compared with the control group, the intervention group had better cognitive (adjusted mean difference 3.5 points (95% CI 0.2, 6.8), p = 0.04; 0.23 SD) and motor (adjusted mean difference 5.5 points (95% CI 2.5, 8.4), p < 0.001; 0.36 SD) development based on the Bayley-III than the control group at follow-up. While the group difference in language scores on the Bayley-III approached significance (adjusted mean difference 3.8 points (95% CI -0.3, 7.9), p = 0.07; 0.25 SD), maternal ratings on the CSBS-DP indicated better symbolic communication and behaviour in the intervention group (adjusted mean difference 0.7 points (95% CI 0.1, 1.4), p = 0.03; 0.27 SD). There were no differences in the communication composite, expressive speech composite, or the total score of the CSBS-DP.
The authors conclude that Baby Triple P for Preterm Infants is effective in improving cognitive, motor, and some aspects of language skills but not child behaviour in very preterm toddlers.
Infants born very preterm (<32 weeks’ gestation) are at heightened risk of adverse neurodevelopmental outcomes.(1) Interventions to improve these vulnerable children’s outcomes should ideally start in the neonatal period and focus on supporting the family unit to promote child development.(2)
In their recent study, Colditz and colleagues report the findings of an appropriately powered, randomised controlled trial of the Baby Triple P for Preterm Infants (3), compared with care as usual.(4, 5) The Triple P approach aims to reduce child behavioural problems by supporting the parenting relationship. This Triple P is distinct from van Os and colleagues “Triple P study” of progesterone as a preventative of preterm birth.(6)
The intervention did not yield benefits for the primary outcome of child behaviour at 2 years’ corrected age. This was a surprising finding given the nature and history of the Triple-P intervention. The authors note that floor effects on the primary outcome measure, the ITSEA, may have limited sensitivity to identify any effects. For instance, the mean scores on the ITSEA subdomains were at least -0.5SD from the normative mean in both groups, suggesting the overall rate of problematic behavioural in the sample was low. In addition, the authors note that the content regarding child behaviour was not delivered at the developmentally appropriate time for parents to apply this information immediately. After the completion of the initial 8 sessions, families engaged with the telephone support offered around 58% of the time. Thus, the interval between the delivery of this aspect of the intervention and the final outcome measurement may have contributed to a loss of efficacy. However, the benefits seen for cognitive, motor, and some aspects of communication development are encouraging.
Although no benefits were found for child behaviour outcomes, this study has provided some promising evidence about the power of supporting parents in caring for their vulnerable preterm infants from the start of their parenting journey. The effect size on motor development is higher than reported in the Cochrane review of early developmental interventions (motor scale development quotient [DQ] standardised mean difference [SMD]: 0.10, 95% CI 0.01 to 0.19; p value = 0.03; 12 studies; 1895 participants), whilst the effects on cognitive outcomes are slightly lower (0.32 SMD DQ; 95% CI 0.16 to 0.47; p value < 0.001; 16 studies; 2372 participants).(7) Longer-term follow-up of such interventions will be crucial in determining the persistence of any benefits to children and families. In addition, some families may benefit more than others from different kinds of interventions,(8) and the factors that predict intervention success should be investigated to ensure interventions are most efficiently provided.
- Johnson S, Marlow N. Early and long-term outcome of infants born extremely preterm. Arch Dis Child. 2017;102(1):97-102.
- Spittle A, Treyvaud K. The role of early developmental intervention to influence neurobehavioral outcomes of children born preterm. Semin Perinatol. 2016;40(8):542-8.
- Colditz PB, Boyd RN, Winter L, Pritchard M, Gray PH, Whittingham K, et al. A Randomized Trial of Baby Triple P for Preterm Infants: Child Outcomes at 2 Years of Corrected Age. J Pediatr. 2019;210:48-54.e2.
- Colditz P, Sanders MR, Boyd R, Pritchard M, Gray P, O’Callaghan MJ, et al. Prem Baby Triple P: a randomised controlled trial of enhanced parenting capacity to improve developmental outcomes in preterm infants. BMC Pediatr. 2015;15:15.
- Msall ME. Promoting Parenting Supports and Engagement for Infants Born Preterm. J Pediatr. 2019;210:10-2.
- van Os MA, van der Ven JA, Kleinrouweler CE, Pajkrt E, de Miranda E, van Wassenaer A, et al. Preventing preterm birth with progesterone: costs and effects of screening low risk women with a singleton pregnancy for short cervical length, the Triple P study. BMC Pregnancy Childbirth. 2011;11:77.
- Spittle A, Orton J, Anderson PJ, Boyd R, Doyle LW. Early developmental intervention programmes provided post hospital discharge to prevent motor and cognitive impairment in preterm infants. Cochrane Database Syst Rev. 2015(11):Cd005495.
- Spittle AJ, Treyvaud K, Lee KJ, Anderson PJ, Doyle LW. The role of social risk in an early preventative care programme for infants born very preterm: a randomized controlled trial. Dev Med Child Neurol. 2018;60(1):54-62.