Examining and interpreting responsiveness of the Diabetes Medication Satisfaction measure
Brod, Meryl; Christensen, Torsten; Kongso, Jens Harald; Bushnell, Donald M.
Journal of Medical Economics
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.