Table 3.
Differences in Demographic and Clinical Characteristics Between the Lower Fatigue (n= 153) and Higher Fatigue (n= 244) Classes
| Characteristic | Lower Fatigue Class n=153 (38.4%) Mean (SD) |
Higher Fatigue Class n=244 (61.3%) Mean (SD) |
Statistic and p-value |
|---|---|---|---|
| Age (years) | 57.8 (11.9) | 53.1 (11.0) | t=4.09, p<.0001 |
| Education (years) | 15.3 (2.5) | 15.9 (2.8) | t=−2.02, p=.04 |
| Karnofsky Performance Status score | 96.6 (7.0) | 91.1 (11.4) | t=5.86, p<.0001 |
| Self-administered Comorbidity Questionnaire score | 3.8 (2.6) | 4.6 (3.0) | t=−2.64, p=.009 |
| Fatigue severity score at enrollment | 1.6 (1.6) | 4.1 (2.2) | t=−12.55, p<.0001 |
| Number of breast biopsies in past year | 1.5 (0.8) | 1.5 (0.8) | U, p=.47 |
| Number of positive lymph nodes | 0.8 (1.9) | 1.0 (2.4) | t=−0.88, p=.38 |
| Number of lymph nodes removed | 4.8 (5.1) | 6.4 (7.5) | t=−2.43, p=.016 |
| n (%) | n (%) | ||
| Ethnicity White Black Asian/Pacific Islander Hispanic/Mixed ethnic background/Other |
100 (65.8) 19 (12.5) 17 (11.2) 16 (10.5) |
155 (63.8) 21 (8.6) 32 (13.2) 35 (14.4) |
Χ2=2.82, p=.42 |
| Married/partnered (% yes) | 64 (42.1) | 100 (41.5) | FE, p=.92 |
| Work for pay (% yes) | 71 (46.4) | 118 (49.0) | FE, p=.68 |
| Lives alone (% yes) | 40 (26.5) | 54 (22.4) | FE, p=.40 |
| Gone through menopause (% yes) | 96 (63.6) | 151 (64.3) | FE, p=.91 |
| Stage of disease 0 I IIA and IIB IIIA, IIIB, IIIC, and IV |
29 (19.0) 66 (43.1) 48 (31.4) 10 (6.5) |
44 (18.0) 85 (34.8) 92 (37.7) 23 (9.4) |
U, p=.13 |
| Surgical treatment Breast conservation Mastectomy |
123 (80.4) 30 (19.6) |
195 (79.9) 49 (20.1) |
FE, p=1.00 |
| Sentinel node biopsy (% yes) | 130 (85.0) | 197 (80.7) | FE, p=.34 |
| Axillary lymph node dissection (% yes) | 50 (32.7) | 98 (40.3) | FE, p=.14 |
| Breast reconstruction at the time of surgery (% yes) | 33 (21.7) | 53 (21.7) | FE, p=1.00 |
| Neoadjuvant chemotherapy (% yes) | 21 (13.7) | 58 (23.9) | FE, p=.014 |
| Radiation therapy during the first 6 months (% yes) | 87 (56.9) | 137 (56.1) | FE, p=.92 |
| Chemotherapy during the first 6 months (% yes) | 36 (23.5) | 97 (39.8) | FE, p=.001 |
Abbreviations: FE = Fisher Exact test, SD = standard deviation, U = Mann Whitney U test