Physical activity, obesity and sedentary behaviour and the risks of colon and rectal cancers in the 45 and up study

Table 3 Cox proportional hazards of incident CC according to BMI, sedentary behaviour and types of physical activity

Variable	Events	No person-years	Age-adjusted HR	Multivariable HR⁽¹⁾
BMI Kg/m²
15- < 23.6	195	154,782	1.00	1.00
≥ 23.6- < 26.2	188	150,904	0.99 (0.81–1.21)	0.90 (0.73–1.12)
≥ 26.2- < 29.4	223	156,854	1.13 (0.93–1.37)	1.12 (0.91–1.38)
≥ 29.4-≤50	232	156,109	1.18 (0.98–1.43)	1.32 (1.08–1.63)
Unknown	8	3273	1.94 (0.96–3.94)	2.21 (1.09–4.49)
P-value^(a)				0.003
P-trend^(b)				0.0006
Sitting hours/day
0- < 3	105	87,149	1.00	1.00
3- < 5	228	167,892	1.13 (0.90–1.42)	0.98 (0.77–1.25)
5- < 8	267	178,262	1.24 (0.99–1.56)	1.12 (0.88–1.42)
8+	165	143,987	0.95 (0.75–1.22)	1.02 (0.79–1.32)
Unknown	81	44,633	1.51 (1.13–2.02)	0.92 (0.67–1.28)
P-value^(a)				0.55
P-trend^(b)				0.88
Moderate activity minutes/week
None	52	30,194	1.00	1.00
> 0–149	175	137,275	0.73 (0.54–1.00)	1.08 (0.76–1.54)
150 or more	583	433,966	0.78 (0.58–1.03)	1.25 (0.90–1.74)
Unknown	36	20,487	1.01 (0.66–1.55)	1.09 (0.65–1.82)
P-value^(a)				0.17
P-trend^(b)				0.76
Vigorous activity minutes/week
None	423	270,374	1.00	1.00
Any amount:^(*)	220	248,354	0.56 (0.48–0.66)	0.78 (0.65–0.93)
> 0–74	97	102,607	0.60 (0.48–0.75)	0.78 (0.61–0.98)
75 or more	123	145,747	0.54 (0.44–0.66)	0.78 (0.63–0.97)
Unknown	203	103,194	1.26 (1.07–1.49)	0.98 (0.81–1.18)
P-value^(a)				0.02
P-trend^(b)				0.11

⁽¹⁾Multivariable models adjusted for: birth cohort, sex, education, BMI, sitting time, time spent on moderate and vigorous activity, smoking, alcohol, country of birth, guidelines of fruit and vegetables, weekly intake of processed food, red meat and fibre, aspirin, parental history of CRC and history of colorectal testing
^(a)‘P-value’ for each variable corresponds to a test of whether all HRs = 1
^(b)‘P-trend’ is for test of linear association in the log hazard scale and obtained by substituting the categorical versions of covariates in the Cox model with continuous or ordinal versions where appropriate
‘Unknown’ category was excluded from the estimation of P-values and P-trends.
^(*)The “any amount” category was derived by combining the “> 0–74” and “75 or more” and the HR for “any amount” was estimated by fitting a separate multivariate model

ISSN: 1471-2458