Fixed-Dose Combination Antidiabetic Therapy: Real-World Factors Associated with Prescribing Choices and Relationship with Patient Satisfaction and Compliance

Compliance with antidiabetic therapy has the potential to impact on the risk for complications by an effect on glycemic control. Fixed-dose combinations (FDCs) offer a simplified dosing regimen that may improve patient compliance. We undertook a retrospective database analysis to understand the real-world association between FDCs, treatment practices, glycated hemoglobin (HbA(1c)) levels, and patient perspectives in type 2 diabetes. Data were drawn from the Adelphi Diabetes Disease Specific Programme (DSP), a multicenter, patient recordbased market research study of primary care physicians and diabetologists/endocrinologists in Europe. The study is based on physician interviews, completion of detailed patient record forms by physicians, and a self-completion questionnaire by patients. Regression analyses were used to identify factors associated with (1) physician-reported dipeptidyl peptidase-4 inhibitor (DPP-4)/metformin FDC prescribing in dual or triple therapy regimens; (2) HbA1c of patients prescribed a DPP-4 FDC alone versus free-form DPP-4 plus metformin dual therapy regimens; and (3) differences between patients prescribed any oral antidiabetic therapy (OAD) FDC therapy (alone or in combination with one other OAD) versus those prescribed dual or triple OAD free-form combination therapy. Physician-reported data were available for 5891 patients (mean age 61.5 years, 43% female, mean duration since diagnosis 5.7 years). Factors associated with DPP-4 FDC usage included physicians' reason for choice being "improves patient compliance." The relative mean % HbA(1c) level associated with being on a DPP-4 FDC rather than free-form independent of the physician perception of patient compliance was 0.25 lower (CI -0.40 to -0.09). When physician-perceived patient compliance was described as "fairly compliant" rather than "poorly compliant" or "not at all compliant," the relative mean % HbA1c level was 0.42 lower (CI -0.67 to -0.18). Similarly, being perceived as "fully compliant" rather than "fairly compliant" was associated with a relative mean % HbA(1c) level that was 0.17 lower (CI -0.31 to -0.02). A significant predictor for the current regimen being any FDC (alone or in combination with one other OAD) regimen was patients' satisfaction with treatment (odds ratio 1.32; 95% CI 1.10 to 1.58; P=0.003). These results suggest that DPP-4 FDC prescribing is considered to be a positive prescribing choice to improve compliance and that choice is associated with improved glycemic control. From the patient's perspective, the decision to prescribe an FDC is associated with improved satisfaction with treatment.