Table 1.
Comparison of variables between rare pathogens and common pathogens groups.
| Variables | Rare Pathogens (n=32) |
Common Pathogens (n=187) |
P-value | Logistic regression P-value |
|---|---|---|---|---|
| Age (yrs) | 65.6 ± 12.7 | 65.4 ± 11.3 | 0.9557 a | |
| Gender (male/female) | 11/21 | 81/106 | 0.4387 c | |
| BMI (kg/m2) | 25.3 ± 3.1 | 24.4 ± 3.2 | 0.1463 a | 0.071 |
| Joint (hip/knee) | 15/17 | 104/83 | 0.8412 b | |
| Smoking (y/n) | 7/25 | 56/131 | 0.4047 c | |
| CCI | 3.1 ± 1.4 | 2.4 ± 1.4 | 0.0049 a | 0.006 |
| PIP (y/n) | 26/6 | 103/84 | 0.0173 c | 0.029 |
| Tsukayama Type [(II or III)/IV] | 5/27 | 26/161 | 0.7855 c | |
| Sinus tract (y/n) | 14/18 | 46/141 | 0.032 c | |
| Laboratory data | ||||
| WBC (×109/l) | 6.5 ± 2.3 | 7.6 ± 5.2 | 0.2451 a | |
| CRP (mg/l) | 28.2 ± 28.5 | 44.3 ± 44.1 | 0.0475 a | |
| ESR (mm/h) | 63.1 ± 33.8 | 62.1 ± 33.8 | 0.8846 a | |
| SF WBC (/ml) (interquartile range) |
8788 (3591, 13941) |
9107 (4544, 30032) |
0.1944 d | |
| SF PMN (%) | 76.1 ± 19.3 | 74.9 ± 16.4 | 0.7004 a | |
| Culture positive rate (%) | 53.1 | 73.8 | 0.0216 c | |
| Polymicrobial infection rate (%) | 25 | 9.1 | 0.0155 c | |
a
Independent-samples t-test. Quantitative data are expressed as mean ± standard deviation.
b
Chi-squared test.
c
Fisher’s exact test.
d
Mann-Whitney U test.
BMI, body mass index; CCI, Charlson comorbidity index; PIP, preoperative invasive procedures; WBC, white blood cell count; CRP, C-reaction protein; ESR, erythrocyte sedimentation rate; SF, synovial fluid; PMN, polymorphonuclear neutrophils.