Table 4.
Associations of Dietary OBS Measures With Incident, Sporadic Colorectal Adenoma According to Lifestyle OBS in Pooled Data From 3 Case-Control Studies (CPRU Study, 1991–1994; MAP I Study, 1994–1997; and MAP II Study, 2002)
| Dietary OBSa | Lifestyle OBS |
||||||||
|---|---|---|---|---|---|---|---|---|---|
| Tertile 1 |
Tertile 2 |
Tertile 3 |
|||||||
| No. of Cases | RRb | 95% CI | No. of Cases | RRb | 95% CI | No. of Cases | RRb | 95% CI | |
| OBS–equal weight | |||||||||
| Tertile 1 | 160 | 1.00 | Referent | 93 | 1.00 | Referent | 67 | 1.00 | Referent |
| Tertile 2 | 117 | 0.78 | 0.55, 1.10 | 69 | 0.92 | 0.61, 1.36 | 50 | 0.47 | 0.30, 0.76 |
| Tertile 3 | 99 | 0.90 | 0.62, 1.32 | 86 | 0.91 | 0.62, 1.39 | 48 | 0.56 | 0.35, 0.91 |
| Ptrend | 0.51 | 0.66 | 0.02 | ||||||
| OBS–lit. review | |||||||||
| Tertile 1 | 180 | 1.00 | Referent | 57 | 1.00 | Referent | 46 | 1.00 | Referent |
| Tertile 2 | 156 | 0.69 | 0.50, 1.96 | 77 | 1.16 | 0.76, 1.77 | 50 | 1.10 | 0.68, 1.80 |
| Tertile 3 | 108 | 0.51 | 0.35, 0.73 | 69 | 1.12 | 0.72, 1.72 | 46 | 0.83 | 0.50, 1.38 |
| Ptrend | <0.001 | 0.63 | 0.49 | ||||||
| OBS–a posteriori | |||||||||
| Tertile 1 | 188 | 1.00 | Referent | 93 | 1.00 | Referent | 52 | 1.00 | Referent |
| Tertile 2 | 121 | 0.82 | 0.58, 1.15 | 72 | 0.81 | 0.54, 1.22 | 52 | 0.72 | 0.44, 1.17 |
| Tertile 3 | 95 | 0.65 | 0.45, 0.93 | 74 | 1.01 | 0.66, 1.54 | 42 | 0.58 | 0.35, 0.98 |
| Ptrend | 0.02 | 0.99 | 0.04 | ||||||
| OBS–Bayesian | |||||||||
| Tertile 1 | 197 | 1.00 | Referent | 72 | 1.00 | Referent | 50 | 1.00 | Referent |
| Tertile 2 | 133 | 0.89 | 0.63, 1.24 | 57 | 0.70 | 0.45, 1.07 | 56 | 1.06 | 0.66, 1.70 |
| Tertile 3 | 108 | 0.63 | 0.45, 0.89 | 76 | 0.96 | 0.63, 1.45 | 40 | 0.83 | 0.50, 1.39 |
| Ptrend | 0.01 | 0.87 | 0.49 | ||||||
Abbreviations: CI, confidence interval; CPRU, Cancer Prevention Research Unit; MAP, Markers of Adenomatous Polyps; OBS, oxidative balance score; RR, relative risk.
a OBS–equal weight: all OBS components received equal weights; OBS–lit. review: weights for OBS components were based on effect estimates derived from literature review; OBS–a posteriori: weights for OBS components were based on CPRU Study data; OBS–Bayesian: weights for OBS components were based on Bayesian analysis of case-control data. Tertiles for OBS are sex-specific, and the dietary components were adjusted for total energy intake.
b Adjusted for age, sex, education, family history of colorectal cancer in a first-degree relative, regular aspirin use, regular use of nonsteroidal antiinflammatory drugs, total calcium intake, total vitamin D intake, total energy intake, total folate intake, dietary fiber intake, and hormone therapy (among women).