Is there a relationship between surgical case volume and mortality in congenital heart disease services? A rapid evidence review

Abstract

ObjectiveTo identify and synthesise the evidence on the relationship between surgical volume and patient outcomes for adults and children with congenital heart disease.DesignEvidence synthesis of interventional and observational studies.Data sourcesMEDLINE, EMBASE, CINAHL, Cochrane Library and Web of Science (2009–2014) and citation searching, reference lists and recommendations from stakeholders (2003–2014) were used to identify evidence.Study selectionQuantitative observational and interventional studies with information on volume of surgical procedures and patient outcomes were included.Results31 of the 34 papers identified (91.2%) included only paediatric patients. 25 (73.5%) investigated the relationship between volume and mortality, 7 (20.6%) mortality and other outcomes and 2 (5.9%) non-mortality outcomes only. 88.2% were from the US, 97% were multicentre studies and all were retrospective observational studies. 20 studies (58.8%) included all congenital heart disease conditions and 14 (41.2%) single conditions or procedures. No UK studies were identified. Most studies showed a relationship between volume and outcome but this relationship was not consistent. The relationship was stronger for single complex conditions or procedures. We found limited evidence about the impact of volume on non-mortality outcomes. A mixed picture emerged revealing a range of factors, in addition to volume, that influence outcome including condition severity, individual centre and surgeon effects and clinical advances over time.ConclusionsThe 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.

Trends in Congenital Heart Disease

“…The complex relationship between procedure volume and outcomes has been identified in congenital cardiovascular procedures, and it continues to be refined ( Figure 9). [126][127][128][129] It has become clear from analyses of these data both that surgical outcomes have improved and that there remains significant variability in outcomes and costs, as well, among hospitals. 108,[130][131][132] In addition to measurement of perioperative surgical mortality and long-term survival, the significance of comorbidities as both measurable outcomes and predictors of other outcomes is increasingly well defined.…”

Mortality for Critical Congenital Heart Diseases and Associated Risk Factors in Newborns. A Cohort Study

“…Organizations wishing to assist in the development of congenital and pediatric cardiac centers need to focus on two-way communication and education and to maintain a long-term commitment to each location. 8 , 9 The commitment of the nation in several spheres is fundamental to change this panorama in the public health and is a matter of social security in our country.…”

Diagnostic errors in paediatric cardiac intensive care

“…Some studies have noted a complex and inverse relationship between paediatric cardiac surgical case volumes and poor outcomes, particularly with higher levels of surgical complexity; this may be extrapolated to suggest a lower frequency of diagnostic errors in centres such as the three that are participating in this study. [39][40][41] As such, the results may not be generalisable to smaller paediatric cardiac ICUs, ICUs with mixed cardiac and non-cardiac populations, and non-academic programmes. Participant responses were analysed by centre, and no important differences were found to suggest clustering.…”