Table 4. Sensitivity Analyses of Birth via Cesarean Delivery and Risk of Early-Onset Colorectal Cancer.
| Analysis | Vaginal delivery | Cesarean delivery |
|---|---|---|
| Age at index ≥35 y | ||
| All | ||
| Cases:controls, No. | 234:872 | 21:70 |
| aOR (95% CI)a | 1 [Reference] | 1.19 (0.70-2.05) |
| Females | ||
| Cases:controls, No. | 109:407 | 13:29 |
| aOR (95% CI)a | 1 [Reference] | 2.13 (1.02-4.48) |
| Males | ||
| Cases:controls, No. | 125:465 | 8:41 |
| aOR (95% CI)a | 1 [Reference] | 0.71 (0.30-1.67) |
| Without maternal history of cesarean delivery | ||
| All | ||
| Cases:controls, No. | 503:1978 | 44:153 |
| aOR (95% CI)a | 1 [Reference] | 1.22 (0.85-1.74) |
| Females | ||
| Cases:controls, No. | 246:983 | 26:73 |
| aOR (95% CI)a | 1 [Reference] | 1.63 (1.00-2.66) |
| Males | ||
| Cases:controls, No. | 257:995 | 18:80 |
| aOR (95% CI)a | 1 [Reference] | 0.89 (0.52-1.53) |
| Without maternal history of major comorbiditiesb | ||
| All | ||
| Cases:controls, No. | 504:1988 | 51:163 |
| aOR (95% CI)a | 1 [Reference] | 1.30 (0.92-1.83) |
| Females | ||
| Cases:controls, No. | 246:982 | 30:79 |
| aOR (95% CI)a | 1 [Reference] | 1.70 (1.05-2.74) |
| Males | ||
| Cases:controls, No. | 258:1006 | 21:84 |
| aOR (95% CI)a | 1 [Reference] | 1.00 (0.59-1.69) |
Abbreviation: aOR, adjusted odds ratio.
a
The model was conditioned on matching factors, including age at index date (continuous), sex, calendar year of index date (continuous), and county of residence, and additionally adjusted for maternal and pregnancy-related factors: maternal history of cesarean delivery (yes, no), maternal age at delivery (≤24, 25-29, 30-34, or ≥35 years), maternal country of birth (Nordic, non-Nordic), living with partner (yes, no), maternal educational level (elementary, secondary, or college), and parity (1, 2, 3, or ≥4).
b
Maternal history of major comorbidities included diabetes, gestational diabetes, hypertension, preeclampsia, and inflammatory bowel disease.