Introduction
Hospital readmission is an undesirable, expensive outcome used as a measure of healthcare quality.1 2 Patients with diabetes are more likely to be readmitted than patients without diabetes,3 and up to 20% will be readmitted within 30 days of hospital discharge.4 Several readmission risk factors have been identified, including repeated hospitalizations, hospital length of stay, sociodemographic characteristics, and comorbidities.4 5 However, these risk factors are largely non-modifiable. There is a need to identify more modifiable risk factors for readmission as potential targets for intervention among patients with diabetes.
A robust body of evidence indicates that cardiorespiratory fitness is a strong predictor of morbidity and mortality in patients with diabetes.6–8 Greater exercise capacity is associated with lower mortality and fewer diabetic complications, including cardiovascular events in patients with diabetes with and without pre-existing cardiovascular disease.6 9–11 Exercise capacity is associated with readmission/hospitalization risk in patients with other chronic conditions such as chronic obstructive pulmonary disease (COPD) and heart failure (HF).12–14 In these populations, exercise interventions decrease readmission/hospitalization risk. Whether exercise capacity is associated with readmission risk among patients with diabetes is unknown. The purpose of the present study was to examine whether such an association exists. We hypothesized that lower exercise capacity based on the maximal workload achieved during treadmill stress testing is associated with a higher 30-day readmission rate in patients with diabetes.