High one-year mortality following hospitalization for severe hypoglycemia among patients with diabetes mellitus: findings of a retrospective cohort study at an acute tertiary care hospital in Singapore

Objectives: Little is known about the 1-year short-term mortality rate following hospital admissions with severe hypoglycemia. This study aimed to determine the factors associated with increased 1-year mortality rate following hospitalization in diabetes patients admitted with severe hypoglycemia to the Singapore General Hospital. Methods: Clinical, biochemical, and 1-year mortality data from diabetes patients who were admitted with severe hypoglycemia in the year 2014 were extracted from institutional medical records. Patients who passed away during the episode of admissions with severe hypoglycemia were excluded from the analysis. The clinical and biochemical factors between patients who survived and those who did not survive within 1 year following admission were compared using logistic regression analysis. Results: Three hundred and four patients (181 female and 123 male) were admitted with severe hypoglycemia in 2014, and the mean capillary blood glucose on admission was 2.3 +/- 0.7 mmol/L. Sixty-three (20.7%) patients died within 1-year post-discharge from the hospital. Compared with patients who survived 1-year post-discharge from the hospital, non-survivors were older (69.3 +/- 11.0 vs 75.5 +/- 11.2 years, p < .001), had longer lengths of stay (LOS) (5.0 +/- 7.4 vs 9.0 +/- 12.8 days, p = .02), and had a higher Charlson Comorbidity Index (CCI) (4.1 +/- 1.9 vs 5.9 +/- 2.4, p < .001). Factors associated with increased 1-year mortality risk were age (odds ratio [OR] = 1.06; 95% confidence interval [CI] = 1.03-1.09, p < .01), LOS in hospital (OR = 1.01; 95% CI = 1.01-1.08, p < .01), and CCI (OR = 1.51; 95% CI = 1.31-1.75, p < .01), respectively. Conclusions: Older diabetes patients with more comorbidities and longer LOS were at increased risk of dying within a year of discharge after hospitalization with severe hypoglycemia. Admission with severe hypoglycemia has important prognostic implications. Healthcare professionals should address hypoglycemia and other health issues during the hospital admissions.