Financial performance of English NHS trusts and variation in clinical outcomes: a longitudinal observational study.

Operating margins in English NHS trusts progressively worsened during 2011-2016, and this change was associated with poorer performance on several process measures but not with hospital readmissions or inpatient satisfaction. Significant variation exists between the best and worst financially performing Trusts. Further research is needed to examine the causal nature of relationships between financial performance, process measures and outcomes.