Table 1.
Demographic and Clinical Characteristics of the Study Population and Factors Associated With Cure
| Characteristic | TOC (n = 380), No. (%) | Univariable Analysisa, OR (95% CI) | OMFU (n = 362), No. (%) | Univariable Analysisa, OR (95% CI) | ||
|---|---|---|---|---|---|---|
| Evaluated | Cure | Evaluated | Cure | |||
| Child (age <18 y) | 132 | 125 (95) | 1.2 (.49–3.1) | 125 | 113 (90) | 1.4 (.67–2.8) |
| Adult (age ≥18 y) | 248 | 232 (94) | Ref | 237 | 207 (87) | Ref |
| Male sex | 210 | 195 (93) | 0.64 (.27–1.6) | 200 | 177 (89) | 1.0 (.54–2.0) |
| Female sex | 170 | 162 (96) | Ref | 162 | 143 (88) | Ref |
| Race/ethnicity | ||||||
| Non-Hispanic/Latinob | 303 | 283 (93) | 0.58 (.17–2.0) | 286 | 251 (88) | 0.74 (.31–1.7) |
| Hispanic/Latino | 76 | 73 (96) | Ref | 75 | 68 (91) | Ref |
| Black | 220 | 208 (95) | 1.3 (.55–3.0) | 210 | 187 (89) | 1.2 (.61–2.2) |
| Non-black | 160 | 149 (93) | Ref | 152 | 133 (88) | Ref |
| Largest wound dimensionc, cm | 2.1 (1.5–3.0)d | … | 0.85 (.60–1.2) | 2.2 (1.5–3.0)d | … | 0.85 (.65–1.1) |
| Diameter ≥ median, cm | 199 | 188 (94) | 1.2 (.52–2.8) | 192 | 169 (88) | 0.93 (.49–1.8) |
| Diameter < median, cm | 181 | 169 (93) | Ref | 170 | 151 (89) | Ref |
| Wound areae, cm2 | 3.1 (0.94–7.1)d | … | 0.94 (.86–1.0) | 3.1 (0.94–7.1)d | … | 0.96 (.89–1.0) |
| Positive culturef | 351 | 329 (94) | … | 336 | 297 (88) | 0.54 (.07–4.3) |
| Negative culture | 17 | 17 (100) | … | 15 | 14 (93) | Ref |
| Staphylococcus aureus isolated | 257 | 242 (94) | 1.1 (.43–2.7) | 246 | 220 (89) | 1.3 (.65–2.6) |
| S. aureus not isolated | 111 | 104 (94) | Ref | 105 | 91 (87) | Ref |
| MRSA isolated | 193 | 180 (93) | 0.75 (.31–1.8) | 184 | 162 (88) | 0.89 (.46–1.7) |
| MRSA not isolated | 175 | 166 (95) | Ref | 167 | 149 (89) | Ref |
| MSSA isolated | 64 | 62 (97) | 2.2 (.50–9.6) | 62 | 58 (94) | 2.1 (.71–6.0) |
| MSSA not isolated | 304 | 284 (93) | Ref | 289 | 253 (88) | Ref |
| TMP-SMX | 178 | 167 (94) | 0.96 (.41–2.2) | 168 | 145 (86) | 0.68 (.36–1.3) |
| Clindamycin | 202 | 190 (94) | Ref | 194 | 175 (90) | Ref |
| DOT (0–10 d), per additional day | 10 (10–10)d | … | 1.9 (1.6–2.2) | 10 (10–10)d | … | 1.6 (1.4–1.9) |
| >5 DOT (>15 doses) | 353 | 344 (97) | 41 (15–112) | 338 | 311 (92) | 19 (7.7–48) |
| ≤5 DOT (≤15 doses) | 27 | 13 (48) | Ref | 24 | 9 (38) | Ref |
| >7 DOT (>21 doses) | 340 | 332 (98) | 25 (9.6–64) | 325 | 299 (92) | 8.8 (4.1–19) |
| ≤7 DOT (≤21 doses) | 40 | 25 (63) | Ref | 37 | 21 (57) | Ref |
Data are presented as no. (%) unless otherwise indicated.
Abbreviations: CI, confidence interval; DOT, days of therapy; MRSA, methicillin-resistant Staphylococcus aureus; MSSA, methicillin-susceptible Staphylococcus aureus; OMFU, 1-month follow-up; OR, odds ratio; Ref, referent value; TMP-SMX, trimethoprim-sulfamethoxazole.
aOnly treatment duration was significant, so multivariable analysis was not performed.
bEthnicity reported as “multiple” for n = 1.
cMedian abscess size (cm) was calculated by age group (6–11 months, 1–8 years, ≥9 years) for this determination. At TOC, overall median size was 2.1 (interquartile range [IQR], 1.5–3.0); 6–11 months, 3.0 (IQR, 2.1–3.4); 1–8 years, 2.0 (IQR, 1.5–3.0); ≥9 years, 2.5 (IQR, 1.5–3.2). At OMFU, overall median size was 2.2 (IQR, 1.5–3.0); 6–11 months, 3.0 (IQR, 2.1–3.4); 1–8 years, 2.0 (IQR, 1.5–3.0); ≥9 years, 2.5 (IQR, 1.5–3.5).
dMedian (IQR).
eArea was calculated using the formula for an ellipse: (length × width × π) / 4.
fPrimary wound culture obtained but no result for n = 12 at TOC and n = 11 at OMFU.