Association of centre volume and in-hospital mortality in heart failure hospitalisations

Background Centre volume is an important determinant of outcomes in patients requiring complex medical treatments or surgical procedures. Heart failure hospitalisation (HFH) has become an increasingly complex and resource intensive clinical event. We evaluated the effect of centre volume on mortality and costs in patients with HFH. Methods This was a retrospective registry-based analysis of adult patients discharged with a primary diagnosis of HF from hospitals across New York (NY) State over a 5-year period, between January 2009 and December 2013, using the Statewide Planning and Research Cooperative System inpatient discharge files. The primary outcome of interest was in-hospital mortality. All patients were followed from the day of admission to either in-hospital death or discharge alive. Results 300 972 HFHs from 198 facilities across NY State were included. Five-year centre volume was associated with a decrease in in-hospital mortality in unadjusted (HR=0.872, 95% CI 0.863 to 0.881, p<0.001) and adjusted Cox models (HR=0.869, 95% CI 0.859 to 0.879, p<0.001). After dividing the overall cohort into three groups based on 5-year centre volume, groups with medium and high volume centres had lower in-hospital mortality when compared with the group with low volume centres. The results were consistent in various subgroup analyses. Furthermore, hospitals in the higher centre volume groups had increased HFH costs across different severity of illness categories and involved increased use of cardiac procedures. Conclusions Higher centre volume was associated with lower HFH mortality but increased HFH costs and increased cardiac procedures in a cohort of Medicare and non-Medicare beneficiaries.