Table 2.
Baseline Characteristics of the Diabetic Patients, Classified with The Development of Colorectal Cancer, and Their Use of Metformin
| Variables | Total (n =47597) |
CRC Development |
P Value | |||||
|---|---|---|---|---|---|---|---|---|
| No (n =46683) |
Yes (n =914) |
|||||||
| n | % | n | % | n | % | |||
| Age (year) | ||||||||
| Mean ± SD | 54.39±14.19 | 54.25±14.19 | 61.54±11.77 | <.001 | ||||
| Grouping | 15 – 45 | 12186 | 25.60 | 12102 | 25.92 | 84 | 9.19 | <.001 |
| 45 – 65 | 23728 | 49.85 | 23293 | 49.90 | 435 | 47.59 | ||
| > 65 | 11683 | 24.55 | 11288 | 24.18 | 395 | 43.22 | ||
| Gender | ||||||||
| Female | 22332 | 46.92 | 21910 | 46.93 | 422 | 46.17 | <.001 | |
| Male | 25265 | 53.08 | 24773 | 53.07 | 492 | 53.83 | ||
| mCCI score | ||||||||
| Mean ± SD | 0.38±0.93 | 0.38±0.93 | 0.36±0.96 | .499 | ||||
| Grouping | 0 | 37626 | 79.05 | 36877 | 78.99 | 749 | 81.95 | .104 |
| 1-2 | 7585 | 15.94 | 7466 | 15.99 | 119 | 13.02 | ||
| ≥3 | 2386 | 5.01 | 2340 | 5.01 | 46 | 5.03 | ||
| Ever use of metformin | ||||||||
| No | 28515 | 59.91 | 27823 | 59.60 | 692 | 75.71 | <.001 | |
| Yes | 19082 | 40.09 | 18860 | 40.40 | 222 | 24.29 | ||
| Follow-up time (year), mean ± SD | 7.17±3.21 | 7.22±3.2 | 4.81±2.69 | <.001 | ||||
| Period of metformin use | ||||||||
| Mean ± SD (months) | 18.2±31.13 | 18.26±31.11 | 15.09±32.11 | .002 | ||||
| Grouping (years) | Never use | 28515 | 59.91 | 27823 | 59.6 | 692 | 75.71 | <.001 |
| <5 | 13294 | 27.93 | 13186 | 28.25 | 108 | 11.82 | ||
| 5-10 | 5172 | 10.87 | 5072 | 10.86 | 100 | 10.94 | ||
| >10 | 616 | 1.29 | 602 | 1.29 | 14 | 1.53 | ||
| cDDD of metformin use | ||||||||
| Mean ± SD | 234.97±561.33 | 238.19±565.48 | 70.75±222 | <.001 | ||||
| Grouping | Never use | 28515 | 59.91 | 27823 | 59.6 | 692 | 75.71 | <.001 |
| ≤300 | 9121 | 19.16 | 8972 | 19.22 | 149 | 16.3 | ||
| 300-600 | 3898 | 8.19 | 3857 | 8.26 | 41 | 4.49 | ||
| 600-900 | 2159 | 4.54 | 2145 | 4.59 | 14 | 1.53 | ||
| >900 | 3904 | 8.2 | 3886 | 8.32 | 18 | 1.97 | ||
| Intensity of metformin use (DDD/month) | ||||||||
| Mean ± SD | 5.98±14.01 | 6.07±14.12 | 1.51±4.49 | <.001 | ||||
| Grouping | Never use | 28515 | 59.91 | 27823 | 59.60 | 692 | 75.71 | <.001 |
| ≤10 | 8658 | 18.19 | 8489 | 18.18 | 169 | 18.49 | ||
| 10-20 | 6639 | 13.95 | 6598 | 14.13 | 41 | 4.49 | ||
| >20 | 3785 | 7.95 | 3773 | 8.08 | 12 | 1.31 | ||
The modified Charlson Comorbidity Index (mCCI) score was calculated by subtracting two diabetic conditions from the original Charlson Comorbidity Index score. The cumulative dose of metformin use was presented as cumulative defined daily dose (cDDD). The intensity of metformin use during the treatment period was calculated with dividing cDDD by the period of metformin use.