While a high and rising prevalence of diabetes in acute inpatient settings is well recognised, up to 40% of inpatients with diabetes remain undiagnosed1. In hospital inpatients, including those admitted under general medicine, inpatient hyperglycaemia is associated with increased mortality and morbidity2,3. HbA1c measurement is superior to diagnose diabetes in hospital inpatients as it is unaffected by factors such as stress hyperglycaemia and recent glucocorticoid use. The aims of this study were to investigate the prevalence and outcomes for patients with diagnosed and undiagnosed diabetes admitted to the general medicine ward.
Under the Diabetes Discovery Initiative and using the Cerner MillenniumÒ Health IT Platform, HbA1c testing was performed automatically for all patients aged ≥54 years admitted to Austin Health, a tertiary metropolitan hospital between June 2013 and January 2014. Diabetes was diagnosed in patients with an HbA1c >=6.5%4. Clinical and demographic information was collected by examination of the medical records.
Over 35% (372/1072) of patients admitted under general medicine had an HbA1c >=6.5%. Of these 372 patients (table 1), 72 (19%) had no prior history of diabetes and 76 (20%) had a prior history of diabetes and an HbA1c≥8.5%. While overall HbA1c level did not correlate with length of stay (LOS), in patients with HbA1c ≥8.5%, there was a correlation with length of stay (r=0.23, p=0.04), with each 1% rise in HbA1c corresponding to an increased LOS by 0.75 days. There were no significant differences between the two groups in the rates of intensive care unit admission and inpatient mortality.
Undiagnosed diabetes affects nearly 20% of patients in patients admitted under general medicine with an HbA1c≥6.5. Routine admission HbA1c measurement can identify patients with undiagnosed diabetes as well as patients with poor glycaemic control for review. Further study is required to determine if early identification and management of these patients improves patient outcomes.
Table 1: Characteristics of 372 patients with an admission HbA1c ≥6.5%.