Table 4

Final covariates of excluded and modeled participants

Characteristics

Participants in the Final Model

Excluded Participants

p-value

N (%)

N (%)

Total

14,474 (73)

5378 (27)

Male

5944 (41)

1887 (35)

<.0001

Education

Less than High School

1670 (12)

798 (15)

High School

3751 (26)

1525 (28)

<.0001

Some College

3963 (27)

1407 (26)

College Diploma

5090 (35)

1628 (30)

Income

Less than $20,000 per year

3071 (21)

623 (22)

$20,000 to $35,000 per year

3991 (28)

797 (28)

0.42

$35,000 to $75,000 per year

4904 (34)

914 (32)

$75,0000 or more per year

2508 (17)

484 (17)

Age

Less than 55 years

1885 (13)

585 (11)

55 to 59 years

2583 (18)

848 (16)

60 to 64 years

2759 (19)

1052 (20)

<.0001

65 to 69 years

2654 (18)

1038 (19)

70 to 74 years

2063 (14)

758 (14)

75 to 79 years

1443 (10)

653 (12)

80 or more years

1087 (8)

436 (8)

Black

6291 (44)

2046 (38)

<.0001

Region

Non Belt/Buckle

6802 (47)

2158 (40)

Stroke Belt

5228 (36)

2074 (39)

<.0001

Stoke Buckle

2444 (17)

1145 (21)

Season

Summer

5542 (38)

2080 (39)

Fall

2957 (20)

1116 (21)

0.76

Winter

2891 (20)

1040 (19)

Spring

3084 (21)

1142 (21)

Never Used Alcohol

4291 (30)

1842 (34)

<.0001

Depressed

1605 (11)

653 (13)

0.0047

PCS-12 (mean, stddev)

46.2 (10.6)

45.9 (10.5)

0.0449

stddev = standard deviation; PCS = Physical Components Summary

P-values for categorical variables provided from a chi squared test statistic and for continuous variables provided from a pooled t-test statistic calculated for each variable by inlcusion status.

Kent et al. Environmental Health 2009 8:34   doi:10.1186/1476-069X-8-34