# Table 3 Univariate analysis of factors relating to the index patients' siblings' relationships with their physicians, families and friends and the association of these factors with participation in colonoscopic screening.

Total Participators Non-participators P
(n = 172) (n = 114) (n = 58)
Medical care
Advice by a physician to undergo screening 65 (40.4) 58 (53.7) 7 (13.2) < 10-4
Score for perceived accessibility of colonoscopy centres (1 to 5) 3.8 (1.2) 4.0 (1.2) 3.3 (1.1) 0.0011
Family
Index patient sex: female 84 (48.8) 58 (50.9) 26 (44.8) 0.45
Index patient age at time of diagnosis     0.49
≤ 45 years old 22 (12.8) 16 (14.0) 6 (10.3)
> 45 years old 150 (87.2) 98 (86.0) 52 (89.7)
Number of cases of colorectal cancer declared in first-degree relatives     0.1
0 45 (26.2) 26 (22.8) 19 (32.8)
1 116 (67.4) 79 (69.3) 37 (63.8)
≥ 2 * 11 (6.4) 9 (7.9) 2 (3.4)
Discussion about screening with all brothers and sisters 84 (49.7) 73 (65.2) 11 (19.3) < 10-4
Social network
Belonging to a social group 54 (32.0) 41 (36.9) 13 (22.4) 0.055
Number of contacts with friends or relatives per month     0.24
≤ 2 19 (12.6) 13 (12.6) 6 (12.5)
3 to 11 98 (64.9) 63 (61.2) 35 (72.9)
≥ 12 34 (22.5) 27 (26.2) 7 (14.6)
Structural support score (0 to 4) 2.3 (1.1) 2.4 (1.1) 2.1 (0.9) 0.13
Emotional support score (0 to 4) 3.4 (1.0) 3.5 (0.9) 3.2 (1.2) 0.039
Material support 153 (91.6) 103 (93.6) 50 (87.7) 0.24
1. Quantitative variables: mean, (standard deviation). Qualitative variables: number (percentage)
2. Missing data: advice by a doctor to undergo screening (11), perceived accessibility score (12), discussion of screening with all brothers and sisters (3), belonging to a social group (3), number of contacts with friends and relatives (21), structural support score (24), emotional support score (1), material support (5).
3. * 1 individual reported 4 cases of colorectal cancer in FDRs not documented by genetic analysis.