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. Author manuscript; available in PMC: 2019 Nov 1.
Published in final edited form as: Eur J Gastroenterol Hepatol. 2018 Nov;30(11):1318–1326. doi: 10.1097/MEG.0000000000001252

Table 3.

Multivariable-adjusted associations of risk factors with incident, sporadic colorectal adenoma in three pooled case-control studies (CPRU Study, 1991–1994; MAP I Study, 1994–1997; and MAP II, 2002), stratified by regular non-aspirin NSAID use

Regular use of non-aspirin NSAID
(n = 574)
 No regular use of non-aspirin NSAID
(n = 2,250)
Risk factorsa No. of
Cases		 No. of
Controls		 OR* 95% CI No. of
Cases		 No. of
Controls		 ORb 95% CI
Age quartiles
(years)
 1 (≤ 47) 14 132 1.00 Referent 87 420 1.00 Referent
 2 (48 – 55) 31 114 2.97 1.44, 6.10 156 377 2.00 1.47, 2.73
 3 (56 – 63) 41 109 4.05 1.98, 8.26 205 399 2.52 1.86, 3.41
 4 (≥ 64) 29 104 3.16 1.51, 6.61 226 380 3.51 2.58, 4.77
  Ptrendc <0.01 <0.01
Sex
 Female  52 314 1.00  Referent 255 850 1.00  Referent
 Male  63 145 1.19 0.41, 3.47 419 726 0.94 0.56, 1.55
First-degree
relative with CRC
(%)
 No  96 370 1.00  Referent 560 1,301 1.00  Referent
 Yes  19 89 0.87 0.49, 1.54 114 275 1.09 0.84, 1.40
Smoking status
 Never 41 183 1.00 Referent 204 755 1.00 Referent
 Former 54 213 0.86 0.53, 1.41 300 600 1.47 1.18, 1.80
 Current 20 63 1.75 0.90, 3.41 170 221 2.91 2.22, 3.82
  Ptrendc 0.27 <0.01
Alcohol
consumption
 Non-drinker 49 200 1.00 Referent 279 690 1.00 Referent
 Low 24 144 0.66 0.38, 1.17 166 453 0.87 0.69, 1.11
 High 42 115 1.41 0.85, 2.36 229 433 1.20 0.95, 1.52
  Ptrendc 0.08 0.01
Body mass
index, (kg/m2)
 Normal weight
  (18.5 – 24.9)		 37 163 1.00 Referent 207 636 1.00 Referent
 Underweight
  (<18.5)		 0 2 n/a n/a n/a 11 20 1.49 0.66, 3.33
 Overweight
  (25.0 – 29.9)		 32 148 0.73 0.41, 1.28 292 627 1.25 1.00, 1.56
 Obese (≥ 30) 46 146 1.19 0.69, 2.04 164 293 1.67 1.28, 2.17
  Ptrendc 0.44 0.06
Height, quartiles
(inches)
 1 (≤ 63.5) 25 102 1.00 Referent 131 330 1.00 Referent
 2 (63.6 – 65.4) 29 141 0.76 0.40, 1.43 216 506 1.08 0.82, 1.41
 3 (65.5 – 69.4) 24 92 0.99 0.50, 1.93 147 314 1.20 0.89, 1.62
 4 (≥ 69.5) 37 124 1.51 0.82, 2.80 180 426 1.39 1.05, 1.85
 Ptrendc 0.10 0.01
Physical activity,
quartiles
 1 35 121 1.00 Referent 192 396 1.00 Referent
 2 26 107 0.91 0.50, 1.68 162 394 0.89 0.69, 1.17
 3 25 110 0.88 0.48, 1.62 156 399 0.89 0.68, 1.16
 4 29 121 0.94 0.52, 1.71 164 387 0.85 0.65, 1.11
 Ptrendc 0.86 0.31
Dietary Intakes
 Percent calories
 from total fat,
 quartiles
 1 30 110 1.00 Referent 152 402 1.00 Referent
 2 21 100 0.81 0.39, 1.67 165 406 1.14 0.85, 1.54
 3 28 119 0.92 0.38, 2.21 176 391 1.42 0.97, 2.06
 4 36 130 1.14 0.37, 3.49 181 377 1.57 0.96, 2.55
 Ptrendc 0.72 0.02
Percent calories
from saturated
fat, quartiles
 1 28 99 1.00 Referent 156 414 1.00 Referent
 2 27 118 0.76 0.38, 1.53 183 388 1.24 0.92, 1.67
 3 29 113 0.80 0.33, 1.97 156 396 1.15 0.79, 1.67
 4 31 129 0.70 0.23, 2.15 179 378 1.37 0.86, 2.18
 Ptrendc 0.66 0.17
Dietary fiber,
quartiles
 1 25 113 1.00 Referent 164 399 1.00 Referent
 2 25 110 1.15 0.59, 2.27 193 398 1.26 0.95, 1.66
 3 37 114 1.52 0.74, 3.09 158 394 1.17 0.86, 1.59
 4 28 122 1.34 0.57, 3.17 159 385 1.26 0.87, 1.82
 Ptrendc 0.50 0.34
Totaldcalcium,
quartiles
 1 23 118 1.00 Referent 189 394 1.00 Referent
 2 29 112 1.36 0.70, 2.63 179 394 0.95 0.72, 1.25
 3 35 106 2.07 1.03, 4.17 141 404 0.72 0.53, 0.97
 4 28 123 1.30 0.61, 2.75 165 384 0.93 0.68, 1.28
 Ptrendc 0.72 0.42
Totald folic acid,
quartiles
 1 25 117 1.00 Referent 186 395 1.00 Referent
 2 36 103 1.54 0.79, 3.01 196 404 1.04 0.78, 1.38
 3 33 118 1.16 0.56, 2.40 138 391 0.74 0.54, 1.03
 4 21 121 0.73 0.34, 1.56 154 386 0.92 0.66, 1.28
 Ptrendc 0.10 0.49
Total fruits &
vegetables,
quartiles
 1 23 113 1.00 Referent 183 391 1.00 Referent
 2 32 112 1.62 0.86, 3.08 180 399 0.95 0.73, 1.23
 3 32 124 1.39 0.71, 2.71 153 394 0.83 0.62, 1.11
 4 28 110 1.38 0.65, 2.94 158 392 0.89 0.64, 1.23
 Ptrendc 0.58 0.44
Total red &
processed
meats,
quartiles
 1 27 98 1.00 Referent 131 363 1.00 Referent
 2 29 131 0.82 0.43, 1.56 187 462 1.07 0.80, 1.42
 3 29 108 0.89 0.44, 1.81 165 355 1.08 0.79, 1.49
 4 30 122 0.70 0.31, 1.56 191 396 1.04 0.73, 1.49
 Ptrendc 0.42 0.86
HRT use
(women)
 No 94 909 1.00 Referent 586 1,270 1.00 Referent
 Yes 21 136 0.77 0.41, 1.42 88 306 0.87 0.64, 1.18
Oxidative
balance score,
quartilese
 1 37 116 1.00 Referent 260 393 1.00 Referent
 2 34 113 1.02 0.58, 1.79 151 396 0.59 0.45, 0.76
 3 21 121 0.67 0.35, 1.28 143 388 0.58 0.44, 0.77
 4 23 109 0.77 0.39, 1.54 120 399 0.50 0.37, 0.69
 Ptrendc 0.33 <0.01

Abbreviations: CPRU, Cancer Prevention Research Unit; CRC, colorectal cancer; CI, confidence interval; HRT, hormone replacement therapy; MAP, Markers of Adenomatous Polyps; MET, metabolic equivalents of task; NSAID, nonsteroidal anti-inflammatory drugs excluding aspirin; OR, odds ratio.

a

Quartiles of age were based on the distribution among the controls. Quartiles of physical activity were based on the study-specific distribution among the controls. Cutpoints for alcohol intake were based on the sex-specific distribution among the controls and were defined as follows for low / high intake: ≤ 2.5 / > 7 drinks/week among males, and ≤ 1 / > 4 drinks/week among females. Cut-points for height quartiles were based on the sex-specific distribution among the controls and were defined as follows: 67.4, 69.4, and 71.4 inches among men, and 62.5, 63.5, and 65.4 inches among women. Quartiles for all dietary intake variables were based on the sex- and study-specific distribution among controls. Quartiles for the oxidative balance score were based on the study-specific distribution among controls.

b

Odds ratios and 95% confidence intervals from unconditional logistic regression models. Covariates for all models, except as noted below included age, sex, family history of colorectal cancer in a first-degree relative, smoking, alcohol intake, body mass index, height, physical activity, hormone therapy (among women), regular aspirin use, and total calcium, folate, dietary fiber, total energy, total fat, saturated fat, total fruit and vegetable, and total red and processed meats intakes. The model for fat does not include total saturated fat, the model for saturated fat does not include total fat, the model for dietary fiber does not include total fruits and vegetables, and model for total fruits and vegetables intakes does not include dietary fiber. Covariates for the model for the oxidative balance score include age, sex, education, family history of colorectal cancer in a first-degree relative, regular aspirin use, hormone replacement therapy (among women), and total calcium, total vitamin D, total energy, total folate, and dietary fiber intakes.

c

Ptrend values (2-sided) were calculated by including the median of each quartile of each variable as a continuous variable in the multivariable models, except the model for body mass index, where the median of the underweight category was excluded.

d

Total = dietary + supplemental.

e

Oxidative balance score calculated as described in the Statistical Analysis section of the text; a higher OBS reflects higher antioxidant relative to pro-oxidant dietary and lifestyle exposures.