TABLE 1.
Baseline characteristics of the study population
| Parameter | Value for population analysis groupa |
||||||
|---|---|---|---|---|---|---|---|
| Overall (n = 200)c | SAB infection source |
Outcome |
|||||
| Hemodialysis (n = 100) | Postsurgical (n = 100) | P valueb | Failure (n = 60) | Cured (n = 133) | P valueb | ||
| Sex | |||||||
| Male | 89 (44.5) | 45 (45) | 44 (44) | 1.00 | 23 (38.3) | 64 (48.1) | 0.22 |
| Female | 111 (55.5) | 55 (55) | 56 (56) | 37 (61.7) | 69 (51.9) | ||
| Race | |||||||
| White | 96 (49.0) | 23 (23.2) | 73 (75.3) | <0.0001 | 35 (59.3) | 59 (45.4) | 0.086 |
| African-American | 100 (51.0) | 76 (76.8) | 24 (24.7) | 24 (40.7) | 71 (54.6) | ||
| Age (yrs) | 58 [18, 84] | 55 [23, 84] | 60 [18, 83] | 0.06 | 63 [26, 84] | 55 [19, 83] | 0.009 |
| Route of acquisition | |||||||
| Hospital | 60 (30.3) | 9 (9.0) | 51 (52.0) | <0.0001 | 22 (37.3) | 36 (27.3) | 0.18 |
| Community | 129 (65.2) | 85 (85.0) | 44 (44.9) | 33 (55.9) | 91 (68.9) | ||
| Nursing home | 9 (4.5) | 6 (6.0) | 3 (3.1) | 4 (6.8) | 5 (3.8) | ||
| APACHE II score | 14 [1, 27] | 16 [8, 27] | 13 [1, 26] | <0.0001 | 16 [1, 26] | 14 [3, 27] | 0.001 |
| Reported duration of symptoms (days) | 2 [0,30] | 2 [1, 26] | 1 [0, 30] | 0.61 | 2 [0, 26] | 1 [1, 30] | 0.71 |
| Persistent fever at 72 h | 113 (65.3) | 70 (78.7) | 43 (51.2) | 0.0002 | 25 (49.0) | 82 (70.7) | 0.009 |
| Methicillin-resistant S. aureus | 116 (58) | 57 (57) | 59 (59) | 0.89 | 44 (73.3) | 68 (51.1) | 0.004 |
| Metastatic diseased | |||||||
| Any | 62 (31.2) | 41 (41.0) | 21 (21.2) | 0.004 | 24 (40.0) | 36 (27.3) | 0.09 |
| Osteoarticular | 23 (11.6) | 14 (14) | 9 (9.1) | 0.38 | 12 (20.0) | 11 (8.3) | 0.03 |
| Endocarditis | 26 (15.0) | 20 (22) | 6 (7.3) | 0.010 | 12 (21.4) | 14 (12.6) | 0.17 |
| Others | 34 (17.1) | 24 (24) | 10 (10.1) | 0.014 | 10 (16.7) | 22 (16.7) | 1.00 |
| Positive blood culture on follow-upe | 76 (47.5) | 55 (59.8) | 21 (30.9) | 0.0004 | 24 (52.2) | 49 (44.1) | 0.38 |
| Alpha-toxin ELISA negative | 27 (13.5) | 11 (11.0) | 16 (16.0) | 0.4222 | 12 (20.0) | 15 (11.3) | 0.0482 |
| Alphta-toxin ELISA positive | 173 (86.5) | 89 (89.0) | 84 (84.0) | 48 (80.0) | 118 (88.7) | ||
| Anti-alpha-toxin-neutralizing antibody seronegative | 156 (78.0) | 77 (77.0) | 79 (79.0) | 0.8646 | 48 (80.0) | 104 (78.2) | 0.8508 |
| Anti-alpha-toxin-neutralizing antibody seropositive | 44 (22.0) | 23 (23.0) | 21 (21.0) | 12 (20.0) | 29 (21.8) | ||
a
Data are reported as the number (with the percentage of the total in parentheses) for categorical variables; continuous variables are reported as means [with the minimimum and maximum values in brackets].
b
P values were calculated using Fisher's exact test for categorical variables and the Kruskal-Wallis test for continuous variables.
c
Not all patient-related information was available for all subjects.
d
The total number of study subjects with metastatic disease is less than the sum for the specific metastatic sites because some patients had >1 metastatic infection sites.
e
Follow-up blood cultures were not available for all study subjects.