Adherence to insulin therapeutic regimens in patients with type 1 diabetes. A nationwide survey in Brazil

Abstract Aims Determine the relationship between self-reported adherence to insulin therapeutic regimens in Brazilian patients with type 1 diabetes and demographic, clinical data, glycemic control and cardiovascular risk factors. Methods This was a cross-sectional, multicenter study conducted between August 2011 and August 2014 in 10 Brazilian cities. Data were obtained from 1,698 patients, aged 30.0±11.90 years (55.5% females, 53.6% Caucasians) with a diabetes duration of 15.4±1.9 years. Adherence was evaluated using an adapted 4-item Morisky Medication Scale (MMAS) questionnaire. Results A total of 166 (9.8%), 717 (42.2%) and 815 (48.0%) of the patients reported maximal (group 0), moderate (group 1) and minimal (group 2) adherence to their insulin therapeutic regimen, respectively. A significant difference in HbA1c was observed in patients from group 2, 9.2±2.2% (77±25 mmol/mol) compared to group 1, 8.9±2.0% (74±22 mmol/mol) and group 0, 8.6 ± 1.9% (71±21mmol/mol) (p=0.003). A multivariate logistic analysis revealed that the significant independent variables related to higher insulin therapeutic regimen adherence were older age, higher adherence to diet, lower rate of self-reported hypoglycemia in the last month, low economic status and living in the Southeast region. Insulin therapeutic regimens, number of daily insulin injections, self-monitoring of blood glucose, gender, ethnicity and cardiovascular risk factors were not related to adherence. Conclusions Most Brazilian T1D patients did not adhere to their prescribed insulin therapeutic regimen, according to the MMAS 4-item scale. This tool should be initially used to identify non-adherent patients and help them overcome the barriers to adherence to their prescriptions.