Aim: To assess the reliability and validity of the Diabetes Medication System Rating Questionnaire among 537 US adults with Type 2 diabetes using five different diabetes medication regimens (oral agents with and without insulin; insulin only by syringe and by pen; glucagon-like peptide 1 agents).
Methods: The Diabetes Medication System Rating Questionnaire assesses the treatment experience of patients using any diabetes medication system that uses nine measures (Convenience, Negative Events, Interference, Self-Monitoring of Blood Glucose Burden, Efficacy, Social Burden, Psychological Well-Being, Treatment Satisfaction, Treatment Preference). It was administered via an initial online survey, along with other validated measures of treatment satisfaction and medication adherence, with a retest administered within 2 weeks. Participants were 52.5% male, 57.4% aged 40-64 years, 83.6% white and 95.2% non-Hispanic. Most (75.6%) had attended college and 58.3% had been diagnosed with diabetes for more than 10 years.
Results: Median inter-item agreement was 0.86. Median test-retest reliability was also 0.86. All correlations between Diabetes Medication System Rating Questionnaire measures and criterion measures of treatment satisfaction and adherence were statistically significant (P<0.01) in the expected direction. Correlations between Diabetes Medication System Rating Questionnaire and the corresponding criterion measures of treatment satisfaction ranged from 0.349 to 0.629 (absolute values; interpolated median 0.568); correlations of the same measures with adherence ranged from 0.384 to 0.450 (absolute values; mean 0.411). Diabetes Medication System Rating Questionnaire measures differentiated among groups taking different medications and those using different delivery systems for the same medication.
Conclusions: This study suggests that the Diabetes Medication System Rating Questionnaire has good reliability and validity and provides a more comprehensive set of measures than existing medication satisfaction questionnaires.
© 2011 The Authors. Diabetic Medicine © 2011 Diabetes UK.