Barriers to Metformin Initiation and Adherence following a New Diagnosis of Type 2 Diabetes

Metformin is the first line treatment for type 2 diabetes (T2D). While earlier initiation is associated with achievement of glycemic targets and a delayed need for treatment escalation, metformin initiation and adherence remain suboptimal. We explored contributors to suboptimal metformin initiation and adherence during the year following a T2D diagnosis. From a population of adults diagnosed with T2D between 2014-2018, we randomly identified 100 individuals who were prescribed metformin during the year after diagnosis (starters) and 100 who were not (non-starters). Through physician review of electronic health record (EHR) notes from the year following diagnosis, we explored patient-provider discussions about metformin, reasons metformin was or was not ordered, and reasons for discontinuation. Metformin starters were younger (mean age 53.8 vs. 60.0 years, p<0.001), more likely to be men (64% vs. 50%, p=0.046), and had higher initial HbA1c values (9.1% vs. 7.0%, p<0.001). Though 94/100 starters filled the initial prescription, only 71 were still taking metformin at one year. The most common documented reason for stopping was side effects. Only 18/100 non-starters had a documented patient-provider discussion about metformin, with a desire to try lifestyle modification as the primary reason for not starting metformin. Among the 18 non-starters who discussed metformin, metformin treatment was only revisited with 3. Though our findings are limited by a small sample and the extent of clinical documentation in the EHR, we still captured aspects of metformin treatment not available using structured EHR variables. In conclusion, among metformin starters, efforts to mitigate side effects, including titration strategies or long-acting formulations, may improve metformin adherence. For most non-starters, there was no documented discussion regarding metformin. Strategies that prompt providers to have this important discussion may increase early initiation of this critical medication. Disclosure C. Gong: None. K. Gu: None. M. A. Blatchins: None. P. Mishra: None. R. W. Grant: None. A. Gopalan: None. Funding Kaiser Permanente Northern California