What evidence is there for a relationship between organisational features and patient outcomes in congenital heart disease services? A rapid review

Abstract

The purpose of this rapid evidence synthesis is to support the current NHS England service review on organisation of services for congenital heart disease (CHD). The evidence synthesis team was asked to examine the evidence on relationships between organisational features and patient outcomes in CHD services and, specifically, any relationship between (1) volume of cases and patient outcomes and (2) proximity of colocated services and patient outcomes. A systematic review published in 2009 had confirmed the existence of this relationship, but cautioned this was not sufficient to make recommendations on the size of units needed. Finds a substantial number of studies reporting a positive relationship between volume and outcome, but the complexity of the evidence requires careful interpretation. The heterogeneity of findings from observational studies suggests that, while a relationship between volume and outcome exists, this is unlikely to be a simple, independent and directly causal relationship. The effect of volume on outcome relative to the effect of other as yet undetermined health system factors remains a complex and unresolved research question.