CRD summary

This review found that different strategies promoting child development in pre-term infants showed an overall positive effect, lasting up to 36 months when there was parental involvement. Although the review was generally well conducted, the conclusions should be interpreted with some caution given the pooling of trials with variation in participants, interventions and outcome measures.

Authors' objectives

To ascertain whether early interventions teaching parenting skills, and/or involving parents in the hospital care of their pre-term baby, improve short-term and school-age neurodevelopmental outcomes. The review on which this report is based covered a range of other outcomes, but these were not the primary focus of the article and are not discussed in this abstract.

Searching

The following databases were searched: MEDLINE (1966 to June 2008), EMBASE (1980 to August 2006), CINAHL (1982 to July 2006), PsycINFO (1972 to June 2006) and the Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Library, Issue 2, 2006). Search terms were reported. The search was not restricted by language. Reference lists of articles were also examined. Each article's key words were re-entered into a new search. An expert in neonatal follow-up reviewed the study for completeness.

Study selection

To be eligible, studies needed to be of preterm infants (less than 37 weeks gestational age or below 2500g weight at birth) and include an intervention involving parents to improve infant development. Eligible studies had to measure infant development by standardised scales; a list of eligible scales was provided. The onset of the intervention needed to be in the first 12 months of the infant's life. Eligible study designs were randomised or a quasi-randomised controlled trials, in which the intervention was compared with routine care or no intervention. The primary outcome was long-term neurodevelopment at 12, 24, 36 months and/or 5 years.

Across the trials, infants ranged in prematurity, body weight and health status. Some trials had disease-specific inclusion criteria, whilst a small number were restricted according to parental demographics. Trials generally excluded infants with chromosomal abnormalities, congenital infections, major neurological problems, serious pathology, and history of maternal drug abuse. Interventions varied in their nature, period of application, intensity, setting and parental involvement. Trials took place in the neonatal intensive care unit, hospital setting and/or in the home. The full characteristics of the included trials were described in a separate online appendix (see URL for Additional Data, accessed March 2010).

Articles were assessed for eligibility independently by two researchers.

Assessment of study quality

Methodological quality was assessed in terms of allocation concealment, blindness of intervention, completeness of follow-up and blinding of outcome assessment. Follow-up was categorised as either less than 85% or more than 85% of infants included in the last follow-up.

Assessment of methodological quality was performed by two reviewers, with disagreements resolved by discussion with a third reviewer not participating in study assessment.

Data extraction

Multiple reports of the same trial were included only if each report provided additional relevant outcome data. Authors were contacted for additional information or clarification as required. Neurodevelopmental scores were obtained from comparable tests, assuming a mean of 100 and standard deviation of 15/16.

The extraction of data was performed independently by two reviewers, with disagreements resolved by discussion with a third reviewer not participating in study assessment.

Methods of synthesis

Meta-analyses were performed, incorporating a random-effects model, for continuous data using the weighted mean difference (WMD) with 95% confidence intervals (CIs). Heterogeneity was assessed using the Χ² and I² statistics.

Two subgroup analyses were pre-specified based on neonatal risk and type of intervention. Trials were grouped according to intervention type: Newborn Individualized Developmental Care and Assessment Program (NIDCAP), kangaroo care or any other developmental intervention. For neonatal risk, high-risk infants were defined as infants with brain structural abnormalities, special sensory abnormalities, specific motor abnormalities or chromosomal abnormalities; low risk was defined as infants with the absence of the preceding criteria. Publication bias was assessed using a funnel plot.

Results of the review

Twenty-five randomised controlled trials (RCTs) were included in the review investigating neurodevelopmental outcomes (n=3,509 children). Few trials described randomisation methods in detail, three reported clearly adequate allocation concealment; 21 of 25 blinded the outcome assessor. Four trials had 85% or more outcome data at the last follow-up point.

At six months, scores on mental scales (six trials) and performance scales (four trials) were not significantly different between the treatment groups.

At 12 months, scores on mental scales showed significant differences in favour of the intervention (WMD 5.57, 95% CI 2.29 to 8.86; 12 RCTs), as did scores on the performance scales (WMD 5.10, 95% CI 1.44 to 8.75; nine RCTs).

At 24 months mental scales showed significant differences in favour of the intervention (WMD 7.59, 95% CI 3.51 to 11.67; seven RCTs), but the difference was not statistically significant for performance scales (four trials).

At 36 months there was a statistically significant difference in favour of the intervention for mental scores (WMD 9.66, 95% CI 5.01 to 14.31; two RCTs) but performance scores were not evaluated.

At five years (three trials) there was no statistical difference between treatment groups.

Statistical heterogeneity was present at 12 and 24 months for mental scales, but not clearly present for other outcomes or time points.

Three trials specifically studied high-risk infants and a similar range of effects was observed for available data at six and 12 months. Analyses on intervention type had a range of effect sizes but broadly reflected the main results.

Funnel plots did not show evidence of publication bias.

Authors' conclusions

Different strategies promoting child development in pre-term infants showed an overall positive effect, lasting up to 36 months, when there was parental involvement.

CRD commentary

This review had defined inclusion criteria for participants, interventions, outcomes and study designs. The search encompassing a range of databases and other information sources, without restriction by language. Procedures to minimise bias and error were employed in the selection of studies, data extraction and quality assessment of studies for the review.

The quality of trials was assessed and used to provide an overview of the reliability of the evidence in this area. A narrative synthesis of the trials may have been more appropriate than meta-analysis, given the clinical and statistical heterogeneity observed; this may not have been fully accounted for in subgroup analyses. In particular, the finding of a diminution of effect at five years may not be robust given the differing age-appropriate measurement scales and small numbers of diverse trials. The authors' conclusions should be interpreted with some caution

Implications of the review for practice and research

Practice: The authors stated that the findings of the review and meta-analysis showed the importance of early intervention and teaching parents skills and/or involving parents in the care of their pre-term infant for enhancing child development.

Research: The authors stated that further research is needed to determine the most effective interventions for environmentally at-risk and biologically vulnerable infants. Effective interventions to improve the long-term outcomes for this population and their families are needed.

Funding

None

Bibliographic details

Vanderveen JA, Bassler D, Robertson CM, Kirpalani H. Early interventions involving parents to improve neurodevelopmental outcomes of premature infants: a meta-analysis. Journal of Perinatology 2009; 29(5): 343-351. [PubMed: 19148113]

Original Paper URL

http://www.nature.com/jp/journal/v29/n5/abs/jp2008229a.html

Indexing Status

Subject indexing assigned by NLM

MeSH

Child Development /physiology; Developmental Disabilities /physiopathology /prevention & control /therapy; Early Intervention (Education); Female; Follow-Up Studies; Humans; Infant; Infant Behavior /physiology; Infant Care /methods; Infant, Newborn; Infant, Premature; Intellectual Disability /physiopathology /prevention & control /therapy; Male; Neurology; Parent-Child Relations; Parenting; Pregnancy; Randomized Controlled Trials as Topic; Risk Assessment; Treatment Outcome

AccessionNumber

12009105830

Database entry date

24/03/2010

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.