Overcoming barriers to the use of metformin: patient and provider perspectives

BACKGROUND: Metformin is the first-line treatment for type 2 diabetes mellitus. Observational studies show lower rates of use than would be expected from clinical guidelines. OBJECTIVE: We undertook a qualitative study of barriers to metformin use from the patient and provider perspective. DESIGN: Patient focus group, patient individual interviews, provider interviews, and chart review. Purposive sampling of patients and providers in New York State. PARTICIPANTS: Seven one-on-one patient interviews, one focus group with 13 patients, 10 provider interviews, and manual review of 1259 charts. APPROACH: Grounded theory. RESULTS: Both providers and patients cited potential health benefits as strong reasons to take metformin and describe it as the first-line drug for diabetes. Patients and providers both cited gastrointestinal side effects as the primary barrier to metformin use. Patients described adapting to these side effects and taking metformin at a time that minimizes them. In contrast, providers emphasized dose titration and the use of extended-release formulation as tools for minimizing side effects but were uncertain about the effectiveness of these strategies. CONCLUSION: Metformin is positively viewed by patients and providers, but gastrointestinal side effects are a barrier to its use. There is some consensus on basic measures to improve its tolerability, but these measures are not consistently applied and lack evidence establishing their effectiveness. Pragmatic clinical trial research on optimal dose, formulation, and counseling for new metformin users should be considered.