Strengths and Limitations
This study had several strengths, including its randomized design, which ensured substantially decreased selection bias. The study was well controlled, since only the place of care differed during the intervention. At the 4-month follow-up, 20 (22%) of the originally randomized infants were lost to the PCERA analysis; however, no differences between analyzed infants and dropouts were found, minimizing the risk for attrition bias in this study. Another strength was the robust observational measurement tool used. The PCERA is well used in studies worldwide and suitable for the preterm population,This study had limitations. The sample size was small, due to the main trial being terminated earlier because of benefit of the intervention.