Metformin-induced Vitamin B12 Deficiency Screening: A Quality Improvement Project

Metformin is frequently prescribed to individuals worldwide as a first-line medication for the treatment of Type 2 diabetes mellitus (T2DM). Metformin has been associated with vitamin B12 deficiency in one-in-ten individuals. The American Diabetes Association (ADA) recommends annual screening for B12 deficiency for individuals prescribed metformin. Local Problem: In Utah, over 191,000 adults have been diagnosed with T2DM. Currently, an urban clinic indicated that B12 deficiency screening rates were variable and provider-dependent at their practice site. B12 deficiency is frequently unrecognized because the condition often results in a variety of symptoms that are overlooked or misdiagnosed. Furthermore, missed identification of metformin-induced B12 deficiency can lead to poor health outcomes and increased costs of superfluous medications and treatments targeted at associated symptoms. Methods: A quality improvement project was implemented at a local diabetes and endocrinology clinic to improve clinician screening for vitamin B12 deficiency in patients prescribed metformin. A clinical practice guideline (CPG) was developed and implemented. An electronic health record (EHR) reminder was utilized to support real-time clinician decision-making. A preimplementation questionnaire was administered before an educational staff presentation of the CPG and EHR reminder to identify baseline knowledge and practices. Retrospective and prospective chart audits (occurring in the same months one year apart) were performed to monitor physician orders for serum vitamin B12 levels for metformin-treated individuals. A postimplementation questionnaire assessed the usability, feasibility, and satisfaction of the CPG from the participating clinicians. Interventions: Evidence-based ADA recommendations were used to develop and implement a CPG to increase vitamin B12 screenings in one urban diabetes and endocrinology clinic. Results: Prior to implementation, 62.5% of the clinicians surveyed (n = 8) indicated an interest in a vitamin B12 screening CPG for patients receiving metformin. Post-intervention, 71.4% of the clinicians surveyed (n = 7) indicated that a CPG increased their vitamin B12 screening rates. Chart audit findings showed a 25.7% increase (43.5% in 2022/23 to 69.2% in 2023/24) in vitamin B12 test orders for metformin-treated patients. The chart analysis from 2022/23 and 2023/24 indicated that between 41.3% and 44.5% of patients taking metformin at this clinic had a low or low-normal B12 level, supporting the need for consistent B12 screenings. Conclusion: The CPG offered clinicians evidence-based guidelines to screen and treat metformin-induced vitamin B12 deficiency. Results suggest that implementation of the CPG was associated with an increased rate of vitamin B12 test orders during the intervention period. Implementing a similar CPG in clinics serving patients with diabetes could increase vitamin B12 screening for individuals prescribed metformin, improving patient outcomes.