Effects of insulin initiation on patient-reported outcomes in patients with type 2 diabetes: results from the durable trial.

Aim: To examine changes in patient-reported outcome (PRO) measures in patients with type 2 diabetes (T2DM) on oral agents who initiated insulin (insulin lispro mix 25/75 [LM25] or insulin glargine) in the DURABLE trial (n=580).

Methods: Subjects completed generic and diabetes-specific health-related quality-of-life measures (RAND-36 and Diabetes-39) and a symptom assessment measure (DSC-Revised) at baseline and 6 months post insulin initiation. Mean score change was evaluated. Effect size (ES; Cohen's d) and analysis of covariance were used to examine extent and significance of change both within and between treatment groups.

Results: Subject characteristics were mean age 57 years, males 59%, duration of diabetes 9.6 years, and baseline HbA1c 8.9%. In the total sample, significant (P<0.01) improvements (with small ES) were observed in four of eight RAND-36 subscales (ES range: 0.13-0.24), three of five Diabetes-39 subscales (ES range: 0.09-0.34), and five of eight DSC-Revised subscales (ES range: 0.15-0.38). While significance of within-group changes varied by treatment, only one subscale (physical functioning for LM25) showed deterioration. The changes were not significantly different (P>0.01) between regimens for any subscales.

Conclusions: Our findings suggest that insulin initiation improves selective PRO in patients with poorly controlled T2DM.