Drug titration patterns and HbA1c levels in type 2 diabetes

OBJECTIVE To evaluate oral antidiabetes drug (OAD) use, haemoglobin A(1c) (HbA(1c)) testing and glycaemic control in type 2 diabetes patients. STUDY DESIGN Retrospective analysis based on claims data from the Integrated Healthcare Information Services (IHCIS) National Managed Care Benchmark Database. METHODS OAD use and HbA(1c) testing were analysed for patients with >or= 2 claims indicating diagnosis of type 2 diabetes and >or= 1 90-day OAD treatment period between 1 January, 2000 and 30 June, 2006. Likelihood of HbA(1c) testing was examined using multivariable logistic regression analyses, adjusting for OAD regimen and patients' sociodemographical characteristics. RESULTS Patients were classified based on initial OAD regimen: metformin (MET) (n = 22,203; 41.3%), sulphonylurea (SFU) (n = 18,439; 34.3%), thiazolidinedione (TZD) (n = 7663; 14.3%), SFU + MET (n = 5467; 10.2%) and TZD + MET (n = 2355; 4.2%). A total of 51.5% of patients had HbA(1c) testing during 90 days preceding OAD initiation through regimen completion. Approximately, 65% of MET and 58% of SFU patients had no titration of initial regimen. Patients demonstrating inadequate glucose control decreased from 68.5% at baseline to 46.9% within 90 days of regimen initiation. Multivariable logistic regression indicated several negative predictors of HbA(1c) testing, including SFU use, age 65+ years, moderate insurance copayment and preindex inpatient utilisation. Multivariable logistic regression of variables associated with reduced likelihood of up-titration included TZD, SFU + MET, or TZD + MET treatment, age 18-34 years, Medicare insurance and any preindex healthcare utilisation. CONCLUSIONS Patients are not being transitioned to additional OADs in a stepwise fashion and/or are receiving inadequate titration on current OAD regimens. The low rate of HbA(1c) testing and rates of control are contributing factors.