Table 1

Baseline characteristics of the BCDDP Follow-up Study participants (n = 33,530) by quartile of total physical activity 1,2

Characteristic
PAI Quartile (MET-hours/day)

Q1 34.0–50.1
Q2 50.11–56.59
Q3 56.6–63.43
Q4 63.44–100.2

Number of participants
8382
8450
8345
8353
Physical activity (median hours/day)




     Sleep
7.8
7.7
7.5
7.2
     Light
13.6
10.2
8.0
5.3
     Moderate
2.4
5.5
7.3
8.6
     Vigorous
0.2
0.6
1.2
2.9
Age (years)
61.6
61.3
60.9
61.0
Body mass index (kg/m2)
25.0
24.7
24.5
24.3
Personal history of diabetes mellitus (%)
0.06
0.04
0.03
0.04
Smoking status (%)




     Never smoker
0.53
0.55
0.57
0.58
     Current smoker (< = 30 pack-years)
0.06
0.07
0.06
0.08
     Current smoker (> 30 pack-years)
0.07
0.06
0.05
0.05
     Former smoker (quit < = 14 years prior)
0.14
0.13
0.13
0.11
     Former smoker (quit > 14 years prior)
0.19
0.18
0.17
0.16
Education (> high school; %)
54.8
47.7
46.8
42.8
Race (% white)
89.8
90.1
89.7
87.3

1 Means unless noted otherwise. 2 All values (except age) were directly standardized to the age distribution of the cohort.

Calton et al. BMC Cancer 2008 8:63   doi:10.1186/1471-2407-8-63