Examining and interpreting responsiveness of the Diabetes Medication Satisfaction measure

Abstract

Objective: Treatment satisfaction (TS) is an important patient reported outcome (PRO) in diabetes as it is correlated with outcomes necessary for optimal treatment (e.g., compliance, self-management behaviour). The objective of this study was to examine the responsiveness of the DiabMedSat, a disease-specific PRO measure, assessing Overall, Burden, Efficacy and Symptom TS.

Methods: The DiabMedSat was included in an open label, observational study of the safety and efficacy of biphasic insulin aspart 30 (NovoMix 30) in routine practice with type 2 diabetes. Responsiveness analyses, examining both internal and external responsiveness, were conducted and minimally important differences (MID) assessed.

Results: In 18,817 patients, all TS scores significantly improved after 26 weeks of treatment (p<0.001). The effect sizes for these changes were above 0.5 indicating that the ability to detect change was moderate-to-large in size. Significant differences were found for all TS scores comparing patients who met their HbA_1c goal, who improved but did not meet goal and who did not improve (p<0.01), and for patients who experienced a minor hypoglycaemic event and those who did not (p<0.001). DiabMedSat scores were able to detect changes in patients’ own global rating of satisfaction (MID ranging from 5.3 to 11.7) and in physician-rated satisfaction with patients’ HbA_1c improvement (MID ranging from 5.3 to 10.2).

Conclusions: In the context of an observational study, the DiabMedSat has been shown to be highly responsive to change and can be considered as an acceptable PRO measure for TS in diabetes.