Table 1.
Characteristics of 2983 participants by levels of fatigue at baseline
| Variable (range) | Level of fatigue* |
P for trend | ||
|---|---|---|---|---|
| Low (n = 1334) | Intermediate (n = 1345) | High (n = 304) | ||
| Age (33-45 years), mean (SD) | 40.2 (3.5) | 40.3 (3.6) | 40.4 (3.7) | 0.459 |
| Sex, % | ||||
| Male | 49.9 | 41.8 | 26.0 | <0.001 |
| Female | 50.1 | 58.2 | 74.0 | |
| Ethnicity, % | ||||
| White | 53.7 | 60.0 | 46.1 | 0.920§ |
| African-American | 46.3 | 40.0 | 53.9 | |
| Education (4-20 years), mean (SD) | 15.2 (2.6) | 15.0 (2.5) | 14.4 (2.5) | <0.001 |
| BMI (15.7-65.8 kg/m2), mean (SD) | 27.6 (6.0) | 29.1 (6.9) | 30.7 (7.9) | <0.001 |
| Daily alcohol consumption (0-564.9 mL), mean (SD) | 11.7 (29.7) | 10.2 (20.7) | 9.5 (24.2) | 0.088 |
| Current smoker, % | ||||
| No | 83.0 | 77.8 | 75.0 | <0.001 |
| Yes | 17.0 | 22.2 | 25.0 | |
| Regular use of aspirin, % | ||||
| No | 95.2 | 93.8 | 92.4 | 0.031 |
| Yes | 4.8 | 6.2 | 7.6 | |
| Pain score (0-4), mean (SD) | 0.33 (0.66) | 0.60 (0.88) | 1.24 (1.33) | <0.001 |
| Physical activity score (0-1818), mean (SD) | 423 (313) | 307 (240) | 223 (221) | <0.001 |
| CES-D score (0-54), mean (SD) | 5.9 (5.6) | 9.9 (7.1) | 17.3 (10.6) | <0.001 |
| Sleep quality score (0-8), mean (SD) | 1.7 (1.6) | 2.5 (1.6) | 3.6 (2.0) | <0.001 |
| CRP (0.15-35.6 mg/L), median | 1.15 | 1.47 | 2.16 | <0.001 |
BMI = body mass index; CES-D = Center for Epidemiological Studies Depression Scale; CRP = C-reactive protein; SD = standard deviation
*
For the purpose of the baseline description, fatigue levels were defined as follows: 1) low - a lot of energy `all of the time' or `most of the time; 2) intermediate - a lot of energy `a good bit of the time' or `some of the time'; 3) high - a lot of energy `a little of the time' or `none of the time'.
§
Note that there was a significant non-linear association between ethnicity and level of fatigue as assessed by chi-square test (P<0.001).