Systematic Cochrane reviews in neonatology: a critical appraisal

Background: There is a lack of up-to-date, systematic reviews that critically assess the role and potential limitations of evidence-based medicine (EBM) and systematic reviews in neonatology.

Methods: We performed a systematic literature review of all Cochrane reviews published between 1996 and 2010 by the Cochrane Neonatal Review Group (CNRG). Main outcome parameter: assessment of the percentage of reviews that concluded that a certain intervention provides a benefit, the percentage of reviews that concluded that no benefit was seen, and the percentage of studies that concluded that the current level of evidence is inconclusive.

Results: In total, 262 reviews were assessed, most of which included exclusively preterm infants (146/262). The majority of reviews assessed pharmacological interventions (145/262); other important fields included nutritional (46/262), and ventilatory issues (27/262). In 42/262 reviews, a clear recommendation in favor of a specific intervention was given, whereas 98/262 reviews concluded that certain interventions should not be performed. However, the largest proportion of reviews was inconclusive (122/262) and did not issue specific recommendations. The proportion of inconclusive reviews increased from 30% (1996-2000), to 50% (2001-2005), and finally to 58% for the years 2006-2010. Common reasons for inconclusive reviews were the small number of patients (105), insufficient data (94), insufficient methodological quality (87), and heterogeneity of studies (69).

Conclusion: There is an ongoing need for high-quality research in order to reduce the proportion of inconclusive meta-analyses in the field of neonatology. Funding and research agencies will play a vital role in selecting the most appropriate research programs.