Table 3. Cox Proportional Hazards Regression Analysis of the Cumulative Incidence of Colorectal Cancer.
| Unadjusted Cox regression analysis | Multivariate Cox regression analysis* | |||
|---|---|---|---|---|
| Crude HR (95% CI) | p value | Adjusted HR (95% CI) | p value | |
| Group (vs. control) | ||||
| CKD-/DM+ | 1.26 (1.13–1.40) | <0.001 | 1.34 (1.16–1.55) | <0.001 |
| CKD+/DM- | 1.31 (1.19–1.44) | <0.001 | 1.31 (1.18–1.46) | <0.001 |
| CKD+/DM+ | 1.61 (1.41–1.84) | <0.001 | 1.63 (1.37–1.94) | <0.001 |
| Age (per 1-year increase) | 1.06 (1.06–1.06) | <0.001 | 1.06 (1.06–1.07) | <0.001 |
| Male (vs. female) | 1.46 (1.36–1.57) | <0.001 | 1.55 (1.41–1.72) | <0.001 |
| Income (continuous variable from Medical-aid to 10th) | 0.97 (0.96–0.99) | <0.001 | 0.98 (0.97–1.00) | 0.014 |
| BMI (vs. 20–25 kg/m2) | ||||
| <20 | 1.35 (1.19–1.53) | <0.001 | 1.13 (0.98–1.29) | 0.094 |
| ≥25 | 0.96 (0.89–1.04) | 0.337 | 1.03 (0.94–1.11) | 0.557 |
| Smoking (vs. non-smoker) | ||||
| Ex-smoker | 1.23 (1.09–1.39) | <0.001 | 1.05 (0.91–1.21) | 0.499 |
| Current smoker | 1.25 (1.15–1.36) | <0.001 | 1.17 (1.06–1.30) | 0.003 |
| Drinking (vs. non-drinker) | ||||
| 2–3 times/month | 1.00 (0.89–1.12) | 0.974 | 1.13 (0.99–1.28) | 0.063 |
| 1–2 times/week | 1.05 (0.94–1.17) | 0.393 | 1.15 (1.01–1.30) | 0.030 |
| ≥3 times/week | 1.53 (1.38–1.69) | <0.001 | 1.36 (1.20–1.53) | <0.001 |
| Exercise (vs. ≥3 times/week) | ||||
| None | 1.05 (0.95–1.15) | 0.346 | 1.03 (0.93–1.14) | 0.584 |
| 1–2 times/week | 0.88 (0.78–0.99) | 0.031 | 0.99 (0.88–1.13) | 0.925 |
| CCI score (per 1 unit increase) | 1.21 (1.16–1.25) | <0.001 | 1.09 (1.04–1.13) | <0.001 |
| Family history of cancer (vs. no history) | 0.84 (0.74–0.95) | 0.006 | 1.03 (0.90–1.17) | 0.670 |
| Use of metformin (vs. non-use) | 1.19 (1.07–1.34) | 0.002 | 0.92 (0.78–1.08) | 0.302 |
| Use of aspirin or NSAIDs (vs. non-use) | 1.13 (1.04–1.22) | 0.004 | 0.99 (0.90–1.08) | 0.750 |
HR, hazard ratio; CI, confidence interval; CKD, chronic kidney disease; DM, diabetes mellitus; BMI, body mass index; CCI, Charlson Comorbidity Index; NSAIDs, non-steroidal anti-inflammatory drugs.
*Adjusted for presence of CKD or DM, age, sex, income, BMI, smoker habits, alcohol intake, exercise, CCI score, family history of cancer, metformin use, use of aspirin or NSAIDs.