Predictors of Emergency Department and Outpatient Visits for Hypoglycemia in Type 2 Diabetes: An Analysis of a Large US Administrative Claims Database

BACKGROUND: Although hypoglycemia is a well-recognized complication of type 1 diabetes and insulin treatment in type 2 diabetes, less research exists on hypoglycemia in the large number of patients with type 2 diabetes who are treated with oral antidiabetic agents. OBJECTIVE: To identify predictors of hypoglycemia-related emergency department (ED) and outpatient visits in patients with type 2 diabetes. METHODS: We used the 2004-2008 MarketScan database to conduct a nested case-control analysis. Cohort members were 18 years of age or older with type 2 diabetes and taking an oral antidiabetic agent at cohort entry. We required 12 months or more of continuous enrollment in a noncapitated plan and excluded persons with type 1 or gestational diabetes. Within the cohort, we selected 11,375 cases (first outpatient hypoglycemic event) and 68,247 controls using 6:1 incidence density sampling. A conditional logistic regression model estimated the adjusted odds ratios (AORs) and corresponding 95% confidence intervals of predictors. RESULTS: Cases were more likely than controls to have diabetic complications and other comorbidity, and to be using the most antidiabetic or other medications. The presence of individual micro- and macrovascular complications of diabetes increased the relative rate of hypoglycemia. With no antidiabetic drug therapy as the referent (within 30 days preceding the index date), insulin monotherapy (AOR 1.76; 95% CI 1.50 to 2.05) and insulin in combination with other oral antidiabetic agents (AOR 1.80; 95% CI 1.65 to 1.97) had the highest relative rates of hypoglycemia. Metformin monotherapy (AOR 0.65; 95% CI 0.61 to 0.70), thiazolidinedione monotherapy (AOR 0.71; 95% CI 0.63 to 0.79), and dipeptidyl peptidase-4 inhibitor monotherapy (AOR 0.63; 95% CI 0.45 to 0.89) had decreased relative rates of hypoglycemia. Monotherapy with sulfonylureas, other injectable agents, meglitinides or alpha-glucosidase inhibitors was not predictive. CONCLUSIONS: Medications should be prescribed carefully for patients at high risk of hypoglycemia, particularly those with diabetes complications or those taking insulin alone or in combination. Additional studies are needed to carefully examine the nature of the association between diabetes-related complications and hypoglycemic episodes.