The effectiveness of regionalization of perinatal care services--a systematic review.

Abstract Background Several reports recommend the implementation of perinatal regionalization for improvements in maternal and neonatal outcomes, while research evidence on the effectiveness of perinatal regionalization has been limited. The interventional studies have been assessed for robust evidence on the effectiveness of perinatal regionalization on improving maternal and neonatal health outcomes. Methods Bibliographic databases of Medline, EMbase, EconLit, HMIC have been searched using sensitive search terms for interventional studies that reported important patient or process outcomes. At least two authors assessed eligibility for inclusion and the risk of biases and extracted data from the included studies. As meta-analysis was not possible, a narrative analysis as well as a 'vote-counting' analysis has been conducted for important outcomes. Results After initial screenings 53 full text papers were retrieved. Eight studies were included in the review from the USA, Canada and France. Studies varied in their designs, and in the specifications of the intervention and setting. Only three interrupted time series studies had a low risk of bias, of which only one study reported significant reductions in neonatal and infant mortality. Studies of higher risk of bias were more likely to report improvements in outcomes. Conclusions Implementing perinatal regionalization programs is correlated with improvements in perinatal outcomes, but it is not possible to establish a causal link. Despite several high profile policy statements, evidence of effect is weak. It is necessary to assess the effectiveness of perinatal regionalization using robust research designs in a more diverse range of countries.