Distilling the evidence on developmental care: a systematic review

To determine whether developmental care interventions reduce neurodevelopmental delay, poor weight gain, length of hospital stay, length of mechanical ventilation, physiologic stress, and other clinically relevant adverse outcomes in preterm infants.

Infants born at less than 37 weeks postconceptional age. This review consisted of 31 studies in 4 categories of developmental care interventions, 19 subgroups, and multiple clinical outcomes. The total sample sizes in the individual studies ranged from 16 to 259; the sample size in 18 of the studies was less than 50.

A systematic review, based on the Cochrane Collaboration format, of all randomized trials in which elements of developmental care are compared with routine nursery care and that measured clinically relevant outcomes. Searches were made of MEDLINE from 1966 to July 2000. Additional databases were also searched electronically. Reference lists and bibliographies of relevant articles were hand-searched. Experts in the field were contracted. If more than one study in an outcome category existed, a meta-analysis was conducted.

Outcome measures included the following: length of hospital stay, weight at discharge, neurodevelopment, physiologic parameters, feeding growth, sleep/wake states, age at discharge, neonatal outcomes, cost of hospital stay, and death.

Developmental care interventions showed some benefit to preterm infants with respect to improved short-term growth outcomes, decreased respiratory support, decreased incidence of moderate to severe chronic lung disease, decreased length and cost of hospital stay, and improved neurodevelopmental outcomes to 24 months corrected age. These findings were based on 2 or 3 small trials for each outcome. Although a number of other benefits were shown, those results were from single studies with small sample sizes. The lack of blinding of the assessors of the outcome variables was a significant methodological flaw in half of the studies. The costs of the interventions and personnel were not considered in any of the studies.

In most studies, the inclusion of multiple interventions made the determination of the effect of any single intervention difficult. Although there is evidence of some benefit of developmental care interventions overall and no major harmful effects reported, there were a large number of outcomes for which no or conflicting effects were shown. The single trials that did show a significant effect of an intervention on a major clinical outcome were based on small sample sizes, and the findings often were not supported in other small trials. Before a clear direction for practice can be supported, evidence showing more consistent effects of developmental care interventions on important short- and long-term clinical outcomes is needed. The economic impact of the implementation and maintenance of developmental care practices should be considered by individual institutions.