Method: A retrospective analysis was conducted using longitudinal data (1999-2010) from the Medical Panel Expenditure Survey (MEPS), a nationally representative survey on healthcare utilization and costs in the US. The study population included patients with type 2 diabetes who were pharmacologically treated with an oral hypoglycemic agent (OHA, monotherapy only) who had a diabetes-related hospitalization identified using ICD-9 diagnostic codes from the inpatient and emergency department files. Patients were categorized into two groups: those receiving sulfonylurea (SU; n = 3.2 million) or other OHA (non-SU; 70% metformin, 25% thiazolidinediones, 5% others; n= 5.5 million) after the first admission. Patients receiving insulin, or who had a diagnosis of polycystic ovary syndrome (PCOS) or pregnancy, were excluded. The outcome evaluated in this study was readmission defined as a subsequent admission for a diabetes-related condition within one year of the first admission.
Result: 23% (n=746,579) of patients in the SU group had a readmission while only 16% (n=881,984) in the non-SU group had a readmission. In a multivariable cox proportional hazard regression model that simultaneously accounted for potential confounders (age, gender, region of the country, marital status, year of MEPS data, cardiovascular disease, kidney disease, eye disease, limitations in physical functioning and perceived health status) and for propensity score for SU use, the hazard ratio for experiencing a readmission was 1.29 (95%CI: 1.01-1.66, p-value=0.04) comparing SU users to non-users.
Conclusion: Among patients with type 2 diabetes, SU use is associated with approximately 30% increased risk for readmission compared to use of other OHAs.