Favorable lifestyle before diagnosis associated with lower risk of screen-detected advanced colorectal neoplasia

Table 1 Characteristics of participant’s n (%)

Variable	Total (n = 6315)1 % column	Advanced colorectal neoplasia (n = 311) % row
Screening arm
Fecal immunochemical test	3323 (53)	85 (3)
Flexible sigmoidoscopy	2992 (47)	226 (8)
Age
mean (SD)	62.0 (7.0)	64.2 (6.9)
Sex
Female	3255 (52)	118 (4)
Male	3060 (48)	193 (6)
Occupation
Employed	3186 (50)	115 (4)
Unemployed	2944 (47)	189 (6)
Missing	185 (3)	7 (4)
Education length
Primary school	1008 (16)	58 (6)
High school	2388 (38)	132 (5)
University/college studies of min. 2 yr	2636 (42)	104 (4)
Missing	283 (4)	17 (6)
Ethnicity
Norwegian	5887 (93)	295 (5)
Not norwegian	361 (6)	12 (3)
Missing	67 (1)	4 (6)
Marital status
Single, widowed, divorced	1195 (19)	62 (5)
Married, living together	5032 (80)	247 (5)
Missing	88 (1)	2 (2)
Chronic disease2
Yes	1593 (26)	86 (5)
No	4507 (74)	212 (5)
Missing	215 (3)	13 (6)
Whole meal bread slices per day
< 1.5	1293 (20)	88 (7)
1.5	1895 (30)	83 (4)
3.5	2175 (34)	101 (5)
> 3.5	928 (15)	38 (4)
Missing	24 (0)	1 (4)

¹The number of replies may not sum to the total due to incomplete replies on the lifestyle questionnaire;

²Chronic disease was asked as: have you doing the last 3 years had some chronic disease that limited your physical activity (e.g., problem with the hip or cardiovascular diseases) Demographic characteristics and whole meal bread consumption for participants in the lifestyle sub-study of the Bowel Cancer Screening in Norway - a pilot study.

Table 2 Risk of advanced colorectal neoplasia by single lifestyle factors n (%)

Variable	Total (n = 6315) % column1	Advanced colorectal neoplasia (n = 311) % row	Lifestyle point2	OR, (95%CI)3
Smoking4
Smoker	1988 (31)	140 (7)	0	1.00 (Ref)
Non-smoker	4311 (68)	171 (4)	1	0.53 (0.42-0.68)
Missing	16 (0)	0 (0)
Body Mass Index5
≥ 25.0	3658 (59)	205 (6)	0	1.00 (Ref)
< 25.0	2542 (41)	97 (4)	1	0.78 (0.60-1.01)
Missing	115 (2)	9 (8)
Physical activity 30 min, times per week
< 7	4480 (71)	238 (5)	0	1.00 (Ref)
≥ 7	1504 (24)	58 (4)	1	0.81 (0.60-1.09)
Missing	331 (5)	15 (5)
Alcohol, glasses per week
≤ 14 for male, ≤ 7 for female)	5525 (88)	264 (5)	1	0.63 (0.43-0.93)
Above	514 (8)	34 (7)	0	1.00 (Ref)
Missing	276 (4)	13 (5)
Fruits and vegetables, servings per day
< 3	4621 (73)	244 (5)	0	1.00 (Ref)
≥ 3	1446 (23)	52 (4)	0.5	0.93 (0.67-1.27)
Missing	248 (4)	15 (6)
Red and processed meat, servings per week
> 4	2059 (32)	108 (5)	0	1.00 (Ref)
≤ 4	4093 (65)	196 (5)	1	0.98 (0.76-1.26)
Missing	163 (3)	7 (4)
Fatty fish, servings per week
< 1	1257 (20)	78 (6)	0	1.00 (Ref)
≥ 1	5023 (79)	232 (5)	0.5	0.79 (0.60-1.05)
Missing	35 (1)	1 (3)
C-statistics				0.72 (0.69-0.75)

¹The number of replies may not sum to the total due to incomplete replies on the lifestyle questionnaire;

²One point for each lifestyle adherence, except only 1 point if adherence to both: fatty fish and fruits and vegetables;

³Models are adjusted for: age (continuously), screening arm (flexible sigmoidoscopy, fecal immunochemical), gender (women, men), center (Moss, Bærum), education (primary school, high school, university/college studies of minimum 2 yr) and whole meal bread. Lifestyle factors (Body Mass Index, smoking, alcohol, physical activity, fruits and vegetables, red and processed meat and fatty fish) were mutually adjusted for each other;

⁴18% current smoker, 14% ≤ 10 yr stopped, 28% > 10 yr stopped, 40% never smokers;

⁵43% had a Body Mass Index of 25.0-30.0; 16% had a Body Mass Index of > 30.0. Lifestyle characteristics, point for the lifestyle score, odds ratio (OR) and 95%CI between the single lifestyle factors and the risk of advanced colorectal neoplasia by multivariable logistic regression for participants in the lifestyle sub-study of the Bowel Cancer Screening in Norway - a pilot study.

Table 3 Risk of advanced colorectal neoplasia by the lifestyle score n (%)

	Total (n = 6315) % column1	Advanced colorectal neoplasia(n = 311), n	Absolute risk estimates per 10004	OR, (95%CI)2	P trend5
Lifestyle score3					< 0.001
0-1	371 (6)	32	86.3	1.00 (Ref)
2	1248 (20)	92	73.7	0.82 (0.45-1.16)
3	1749 (27)	71	40.6	0.43 (0.28-0.73)
4	1312 (21)	46	35.1	0.41 (0.23-0.64)
5-6	684 (11)	21	30.7	0.41 (0.22-0.73)
Mising	951 (15)	49
C-statistics				0.71 (0.68-0.74)

¹The number of replies may not sum to the total due to incomplete replies on the lifestyle questionnaire;

²The model was adjusted for age (continuously), screenings arm (fecal immunochemical test, flexible sigmoidoscopy), gender (women, men), center (Moss, Bærum), education (primary school, high school, university/college studies of minimum 2 years) and whole meal bread;

³One point for each lifestyle adherence, except only 1 point if adherence to both: fatty fish and fruits and vegetables;

⁴Absolute risk calculated: with in each score: (n ACN/Total n)*1000;

⁵P trend was calculated using the lifestyle score as continuous. Lifestyle score characteristics, odds ratio (OR) and 95%CI for the risk of advanced colorectal neoplasia by multivariable logistic regression for participants in the lifestyle sub-study of the Bowel Cancer Screening in Norway - a pilot study.