Table 3.
Bivariate Analyses of Potential Predictors of Adverse Outcomes
| Acute Complicated Coursea | Chronic Morbiditya | |||||||
|---|---|---|---|---|---|---|---|---|
| Potential Predictor | Outcome Absent (n = 194) | Outcome Present (n = 62) | Missing | P Value | Outcome Absent (n = 226) | Outcome Present (n = 27) | Missing | P Value |
| Hospital site: HCH | 100 (52) | 29 (47) | 5 | .51 | 110 (49) | 16 (59) | 8 | .30 |
| Age, median (IQR), y | 9.3 (4.0–12.0) | 8.5 (5.4–12.3) | 5 | .98 | 9.0 (4.2–11.9) | 10.1 (5.6–12.3) | 8 | .52 |
| Sex, female | 67 (35) | 32 (53) | 5 | .02 | 89 (39) | 9 (33) | 8 | .54 |
| Location of infectionb | 5 | |||||||
| Upper extremity long bone | 17 (9) | 10 (16) | .10 | 22 (10) | 5 (19) | 8 | .18 | |
| Lower extremity long bone | 91 (47) | 39 (62) | .03 | 117 (52) | 13 (48) | 8 | .72 | |
| Hands | 8 (4) | 4 (7) | .49 | 10 (4) | 2 (7) | 8 | .37 | |
| Feet | 31 (16) | 6 (10) | .22 | 32 (14) | 2 (7) | 8 | .55 | |
| Pelvis or sacrum | 48 (25) | 8 (13) | .05 | 49 (22) | 7 (26) | 8 | .616 | |
| Otherc | 6 (3) | 2 (3) | 1 | 6 (3) | 2 (7) | 8 | .21 | |
| Multifocal infectiond | 5 (3) | 7 (11) | 5 | .01 | 7 (3) | 4 (15) | 8 | .02 |
| Disseminated infectione | 10 (5) | 20 (32) | 5 | < .001 | 19 (8) | 9 (33) | 8 | < .001 |
| Duration of preceding symptoms, median (IQR), d | 4 (2–7) | 4 (2–7) | 5 | .45 | 4 (2–7) | 4 (2–7) | 8 | .85 |
| Tmaxf, median (IQR), °C | 38.7 (37.639.6) | 39.4 (38.440.0) | 5 | < .001 | 38.8 (37.739.8) | 39.4 (38.440.0) | 11 | .06 |
| Fever after > 48 h of antibiotic therapy | 50 (26) | 40 (65) | 5 | < .001 | 72 (32) | 15 (56) | 8 | .01 |
| WBC on admission, median (IQR), ×1000 cells/mL | 10.4 (7.8–14.9) | 13.4 (10.1–16.5) | 18 | .002 | 10.7 (7.8–15.2) | 12.3 (10.3–15.7) | 28 | .07 |
| ESR on admission, median (IQR), mm/h | 45 (24–56) | 52 (40–65) | 17 | .002 | 46 (27–58) | 45 (35–66) | 28 | .26 |
| CRP on admission, median (IQR), mg/L | 47 (21–130) | 129 (61–220) | 14 | < .001 | 57 (25–136) | 138 (65–221) | 25 | .002 |
| CRP ≥ 50 mg/L after 2–4 d of antibiotics | 52 (31) | 36 (68) | 41 | < .001 | 70 (37) | 16 (67) | 47 | .004 |
| CRP ≥ 100 mg/L after 2–4 d of antibiotics | 25 (15) | 26 (49) | 36 | < .001 | 36 (18) | 13 (54) | 32 | < .001 |
| CRP ≥ 150 mg/L after 2–4 d of antibiotics | 15 (9) | 21 (40) | 32 | < .001 | 26 (13) | 9 (38) | 38 | .002 |
| Admitted to ICU | 8 (4) | 8 (13) | 5 | .01 | 13 (6) | 2 (7) | 8 | .67 |
| Suppurative arthritisg | 34 (18) | 25 (40) | 5 | < .001 | 47 (21) | 10 (37) | 8 | .06 |
| Bacteremia | 84 (43) | 33 (53) | 5 | .17 | 101 (45) | 15 (56) | 8 | .28 |
| Bone abscess | 59 (30) | 38 (61) | 5 | < .001 | 80 (35) | 18 (67) | 8 | .002 |
| Causative organism recovery | 130 (67) | 59 (95) | 5 | < .001 | 163 (72) | 24 (89) | 8 | .07 |
| Staphylococcus aureus recovered | 107 (55) | 42 (68) | 5 | .08 | 129 (57) | 19 (70) | 8 | .19 |
| MRSA recovered as causative organism | 21 (11) | 22 (36) | 5 | < .001 | 37 (16) | 7 (26) | 8 | .22 |
| Any surgical intervention | 103 (53) | 58 (94) | 5 | < .001 | 135 (60) | 24 (89) | 8 | .003 |
| Bone debridement | 52 (27) | 50 (81) | 5 | < .001 | 79 (35) | 20 (74) | 8 | < .001 |
| Delayed source control (excluding IR) | 7 (4) | 15 (24) | 5 | < .001 | 18 (8) | 6 (22) | 8 | .017 |
| Delayed source control (including IR) | 14 (7) | 16 (26) | 5 | < .001 | 25 (11) | 6 (22) | 8 | .095 |
| Multiple bone debridements | … | 35 (57) | 5 | 24 (11) | 11 (41) | 8 | < .001 | |
| Severity of illness scoreh, median (IQR) | 1 (0–3) | 6 (1–7) | 28 | < .001 | 1 (0–4) | 6 (1–7) | 40 | .001 |
Data are presented as no. (%) unless otherwise indicated. Bold values indicate significant results.
Abbreviations: CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; HCH, Hasbro Children’s Hospital; ICU, intensive care unit; IQR, interquartile range; IR, drainage performed by Interventional Radiologist; MRSA, methicillin-resistant Staphylococcus aureus; Tmax, maximum temperature; WBC, white blood cell.
aDefined in Methods section.
bTotal > 100% secondary to multifocal infections.
cClavicle, scapula, sternum, or patella.
dDefined as the involvement of ≥2 noncontiguous bones.
eIndicated by the presence of multifocal infection, pneumonia, septic pulmonary embolism, deep vein thrombosis, or endocarditis.
fIn the first 48 hours from presentation.
gSynovial fluid with positive culture, positive Gram stain for bacteria, nucleated cell count ≥ 10 000 cells/mL, or moderate-many neutrophils if nucleated cell count not done (4 cases).
hAs described by Athey et al [30].