Association of Glucose Concentrations at Hospital Discharge With Readmissions and Mortality: A Nationwide Cohort Study

J Clin Endocrinol Metab. 2019 Sep 1;104(9):3679-3691. doi: 10.1210/jc.2018-02575.


Context: Low blood glucose concentrations during the discharge day may affect 30-day readmission and posthospital discharge mortality rates.

Objective: To investigate whether patients with diabetes and low glucose values during the last day of hospitalization are at increased risk of readmission or mortality.

Design and outcomes: Minimum point of care glucose values were collected during the last 24 hours of hospitalization. We used adjusted rates of 30-day readmission rate, 30-, 90-, and 180-day mortality rates, and combined 30-day readmission/mortality rate to identify minimum glucose thresholds above which patients can be safely discharged.

Patients and setting: Nationwide cohort study including 843,978 admissions of patients with diabetes at the Veteran Affairs hospitals 14 years.

Results: The rate ratios (RRs) increased progressively for all five outcomes as the minimum glucose concentrations progressively decreased below the 90 to 99 mg/dL category, compared with the 100 to 109 mg/dL category: 30-day readmission RR, 1.01 to 1.45; 30-day readmission/mortality RR, 1.01 to 1.71; 30-day mortality RR, 0.99 to 5.82; 90-day mortality RR, 1.01 to 2.40; 180-day mortality RR, 1.03 to 1.91. Patients with diabetes experienced greater 30-day readmission rates, 30-, 90- and 180-day postdischarge mortality rates, and higher combined 30-day readmission/mortality rates, with glucose levels <92.9 mg/dL, <45.2 mg/dL, 65.8 mg/dL, 67.3 mg/dL, and <87.2 mg/dL, respectively.

Conclusion: Patients with diabetes who had hypoglycemia or near-normal glucose values during the last day of hospitalization had higher rates of 30-day readmission and postdischarge mortality.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Aged
  • Biomarkers / analysis
  • Blood Glucose / metabolism*
  • Cohort Studies
  • Diabetes Mellitus / metabolism
  • Diabetes Mellitus / mortality*
  • Diabetes Mellitus / therapy
  • Female
  • Follow-Up Studies
  • Hospitalization / statistics & numerical data*
  • Humans
  • Male
  • Mortality / trends*
  • Patient Discharge / statistics & numerical data*
  • Patient Readmission / statistics & numerical data*
  • Prognosis
  • Survival Rate
  • Time Factors


  • Biomarkers
  • Blood Glucose