Monitoring safety and use of old and new treatment options for type 2 diabetic patients: a two-year (2013–2016) analysis

<b>Objective</b>: To compare patients’ and physicians’ perceptions regarding effectiveness and tolerability of non-insulin hypoglycemic drugs in a cohort of type 2 diabetic patients; to verify whether a possible tridimensional link between effectiveness, tolerability, and adherence affects long-term therapeutic outcomes. <b>Methods</b>: A two-year observational study was performed in 1389 Type 2 diabetic patients by involving general practitioner clinics and Diabetes Centers. A decimal scale and the Morisky questionnaire were used, respectively, to assess effectiveness and tolerability perceptions, and medication adherence. <b>Results</b>: Physicians perceived therapy as more efficacious compared to their patients: perceived effectiveness was steady for physicians during the study whereas patients’ perception not significantly decreased (mean score from &gt;8 to 7.84 ± 1.69). Physicians assigned higher tolerability scores compared to patients but only at the beginning of the study; interestingly, physicians’ tolerability perception was poorer than patients’ perception at last follow-up (mean score = 7.57 ± 1.40 vs. 7.88 ± 1.84). Favorable (score &gt;7) patients’ perceptions about treatment effectiveness and tolerability were associated with higher adherence. Patients showed medium adherence across the study. <b>Conclusions</b>: A mutual relationship between clinical effectiveness, adverse drug reactions, and adherence has been established, significantly impacting the clinical management of diabetic patients. A careful monitoring of this link by clinicians appears therefore necessary.