TABLE 2.
Estimates of lung cancer risk associated with metformin use
| Metformin Use | No. of events | Person-Years | Adjusteda HR (95% CI) | |
|---|---|---|---|---|
| Never | 464 | 257,542.42 | 1.00 (reference) | |
| Ever | 283 | 171,015.06 | 1.02 (0.85-1.22) | |
| Total duration, years | ||||
| <2.0 | 100 | 61,047.00 | 1.02 (0.81-1.28) | |
| 2.0 - 4.9 | 93 | 56,423.33 | 1.00 (0.78-1.28) | |
| ≥5.0 | 90 | 53,544.73 | 1.04 (0.78-1.37) | |
| Recency of use | ||||
| Former | 75 | 33,496.72 | 1.19 (0.89-1.58) | |
| Recent | 37 | 21,484.37 | 1.07 (0.75-1.52) | |
| Current | ||||
| <5.0 years | 107 | 75,365.20 | 0.93 (0.74-1.17) | |
| ≥5.0 years | 64 | 40,668.76 | 1.04 (0.76-1.42) | |
| Cumulative dose (mg), quartiles | ||||
| ≤750,000 | 91 | 55,360.21 | 1.00 (0.79-1.27) | |
| 750,001 – 2,300,000 | 84 | 52,118.33 | 0.98 (0.76-1.27) | |
| 2,300,001 – 4,930,000 | 67 | 41,097.81 | 1.04 (0.77-1.39) | |
| >4,930,000 | 41 | 22,438.70 | 1.21 (0.83-1.77) |
a
Stratified on age and adjusted for gender, race/ethnicity, birth year, diabetes duration, BMI, alcohol use, Charlson comorbidity index, smoking history (status and pack-years), education, income level, creatinine level, HbA1c level, and use of other diabetes medications