Assessing the Relationship Between Admission Glucose Levels, Subsequent Length of Hospital Stay, Readmission and Mortality

This study aimed to investigate relationships between dysglycaemia and length of hospital stay, short-term mortality and readmission in an unselected population in an acute medical unit (AMU). The rate of follow up in non-diabetic individuals with hyperglycaemia was also measured. We analysed data from all 1,502 patients admitted through our AMU in February 2010 to assess blood glucose levels on admission, length of stay, 28-day readmissions and mortality, and to determine whether blood glucose > or = 11.1 mmol/l on admission in non-diabetic individuals was followed up. In total, blood glucose was measured on admission for 893 patients. Mean length of stay was 8.8 (standard deviation 11.9) days, for patients with blood glucose < 6.5 mmol/l on admission; 11.3 (13.6) days, for 6.5-7 mmol/l; 10.2 (14.5) days, for 7.1-9 mmol/l; 10.6 (14.9) days, for 9.1-11 mmol/l; 12 (18.4) days, for 11.1-20 mmol/l and 9.1 (11.2) days, for > 20.1 mmol/l. Length of stay for patients with blood glucose > 6.5 mmol/l on admission was significantly longer (p = 0.002). The 28-day readmission rates were 6.4%, 6%, 9.7%, 12.5%, 10% and 15%, respectively, and 28-day death rates were 4.8%, 6%, 5.8%, 17.2%, 17.1% and 6.1%, respectively. Overall, 51.4% of non-diabetic individuals with blood glucose > 11.1 mmol/l on admission were followed up. The study showed that blood glucose > 6.5 mmol/l on admission is associated with significantly longer length of stay. Hyperglycaemia was associated with increased 28-day mortality and readmissions, and is frequently underinvestigated.