Examining correlates of treatment satisfaction for injectable insulin in type 2 diabetes: lessons learned from a clinical trial comparing biphasic and basal analogues

BACKGROUND Successfully managing diabetes is a complex process that includes addressing issues of drug efficacy, safety and treatment satisfaction. Additionally, the combined impact of patient/disease characteristics and treatment outcomes on treatment satisfaction is not well understood. The purpose of this study was to examine the impact of age, weight, gender, co-morbid conditions, diabetes history, treatment burden, efficacy (HbA1c) and side effects (weight gain, hypoglycemic events) on patients' appraisal of treatment satisfaction using linear regression models. METHODS Data from a multi-center, randomized clinical trial comparing the efficacy/safety of biphasic insulin aspart 70/30 (BIAsp 70/30) vs. glargine (Glar) among insulin naïve type 2 patients were analyzed. Subjects were between ages 18-75, with baseline HbA1c > 8% and BMI < or = 40 kg/m2 (N = 233). Treatment satisfaction was assessed by the Insulin Treatment Satisfaction Questionnaire (ITSQ). RESULTS When factors were examined independently, multiple significant relationships (age, co-morbidity, hypoglycemic events, and weight gain) with overall and/or domains of treatment satisfaction were found. However, when all significant relationships were examined together, only neuropathy, treatment efficacy, and number of hypoglycemic events maintained their previous significance. CONCLUSION By examining predictors independently, significant relationships were identified. However, not all findings remained significant when examined in combination with each other. Thus, to more accurately characterize the impact of factors on treatment satisfaction, a more comprehensive approach may be necessary. By improving patient treatment satisfaction, the efficacy of treatments, as well as critical treatment outcomes such as compliance and cost of care should be improved.