Multivariate logistic regression analysis of factors associated with vitamin B12 deficiency
| Model | Variables | OR (95% CI) | P value |
| Model 1 | HbA1c | 0.624 (0.455–0.856) | 0.003 |
| Duration of metformin use | 1.076 (1.005–1.151) | 0.037 | |
| Metformin dose | 1.002 (1.001–1.004) | 0.002 | |
| Model 2 | HbA1c | 0.631 (0.460–0.865) | 0.004 |
| Long-term use of metformin (duration > median duration) | 10.078 (2.729–37.219) | 0.001 | |
| Metformin dose > median dose | 4.429 (1.475–13.303) | 0.008 | |
| Model 3 | HbA1c | 0.647 (0.480–0.874) | 0.005 |
| MUI≥10 | 7.644 (2.109–27.707) | 0.002 |
MUI, metformin usage index;