Table 1.
Risk factors associated with treatment failure among patients with community-associated S. aureus skin and soft tissue infections
| Characteristic | Overall, n = 106 | No failure, n = 84 | Treatment failure, n = 22 | OR (95% CI) | p | aOR (95% CI) | p |
|---|---|---|---|---|---|---|---|
| Mean age, years (±SD) | 41 (±14) | 40 (±13) | 45 (±13) | 0.15 | |||
| Gender | |||||||
| Male | 53 (50%) | 44 (52%) | 9 (41%) | 0.63 (0.24–1.63) | 0.34 | ||
| Race/ethnicity | |||||||
| Black | 8 (8%) | 4 (5%) | 4 (18%) | 4.44 (1.02–19.47) | 0.03 | ||
| Hispanic | 78 (74%) | 64 (76%) | 14 (64%) | 0.547 (0.20–1.49) | 0.23 | ||
| Diabetes | 28 (26%) | 21 (25%) | 7 (32%) | 1.40 (0.50–3.89) | 0.52 | ||
| Obese (BMI ≥ 30)b | 50 (54%) | 38 (50%) | 12 (71%) | 2.40 (0.77–7.48) | 0.12 | ||
| Weight ≥110 kg | 19 (20%) | 12 (15%) | 7 (37%) | 3.21 (1.05–9.80) | 0.04 | ||
| Chronic non-infectious skin disorder | 1 (1%) | 1 (1%) | 0 | 0.99 (0.97–1.01) | 1.00 | ||
| Immunosuppressed at time of visit | 2 (2%) | 2 (2%) | 0 | 0.98 (0.94–1.01) | 1.00 | ||
| Provides healthcare to others | 2 (2%) | 1 (1%) | 0 | 0.99 (0.97–1.01) | 1.00 | ||
| MRSA phenotype | 68 (65%) | 55 (66%) | 13 (59%) | 0.87 (0.49–1.56) | 0.65 | 0.42 (0.12–1.42) | 0.16 |
| MDR | 29 (27%) | 10 (12%) | 19 (86%) | 2.85 (1.07–7.62) | 0.03 | ||
| Prior SSTI | 35 (33%) | 27 (32%) | 8 (36%) | 1.21 (0.45–3.20) | 0.71 | ||
| Prior antibiotic history | 16 (15%) | 11 (13%) | 5 (23%) | 1.95 (0.60–6.36) | 0.32 | ||
| Duration of infection prior to visit ≥7 days | 48 (48%) | 32 (40%) | 16 (76%) | 4.80 (1.59–14.41) | <0.01 | 6.02 (1.74–20.87) | <0.01 |
| Severity | |||||||
| Largest diameter ≥5 cm | 49 (48%) | 34 (42%) | 15 (71%) | 3.53 (1.24–10.02) | 0.01 | 5.25 (1.58–17.42) | <0.01 |
| Lesion area ≥25 cm2 | 37 (35%) | 24 (29%) | 13 (59%) | 3.55 (1.34–9.39) | 0.01 | ||
| Infection characteristics | |||||||
| Erythema | 78 (74%) | 61 (74%) | 17 (77%) | 1.23 (0.40–3.72) | 0.72 | ||
| Drainage | 56 (53%) | 45 (54%) | 11 (50%) | 0.84 (0.33–2.16) | 0.72 | ||
| Ulceration | 30 (29%) | 22 (27%) | 8 (36%) | 1.58 (0.59–4.29) | 0.43 | ||
| Abscess | 76 (72%) | 56 (67%) | 20 (91%) | 4.82 (1.05–22.14) | 0.03 | ||
| Location | |||||||
| Lower extremity | 35 (33%) | 26 (31%) | 9 (41%) | 1.54 (0.59–4.06) | 0.38 | ||
| Head/neck/face | 11 (10%) | 10 (12%) | 1 (5%) | 0.35 (0.40–2.91) | 0.45* | ||
| Trunk | 24 (23%) | 17 (20%) | 7 (32%) | 1.84 (0.65–5.22) | 0.26* | ||
| Axilla | 13 (12%) | 11 (13%) | 2 (9%) | 0.66 (0.14–3.24) | 0.61* | ||
| Upper extremity | 6 (6%) | 5 (6%) | 1 (5%) | 0.75 (0.08–6.79) | 1.00* | ||
| Groin/buttock | 17 (16%) | 14 (17%) | 3 (14%) | 0.79 (0.21–3.03) | 1.00* | ||
| Treatment | |||||||
| I&D only | 4 (4%) | 3 (4%) | 1 (5%) | 1.01 (0.91–1.12) | 1.00 | ||
| I&D + antibiotics | 57 (59%) | 43 (51%) | 14 (64%) | 1.30 (0.68–2.51) | 0.41 | ||
| Antibiotics only | 32 (33%) | 27 (36%) | 5 (24%) | 0.84 (0.63–1.13) | 0.29 | ||
| Antibiotics | |||||||
| Trimethoprim–sulfamethoxazole | 81 (76%) | 65 (77%) | 16 (73%) | 0.78 (0.27–2.27) | 0.65 | ||
| Doxycycline | 12 (11%) | 9 (11%) | 3 (14%) | 1.32 (0.32–5.34) | 0.71 | ||
| Clindamycin | 7 (7%) | 5 (6%) | 2 (9%) | 1.58 (0.26–8.75) | 0.63 | ||
| Cephalexin | 9 (9%) | 7 (8%) | 2 (9%) | 1.10 (0.21–5.71) | 1.00 | ||
| Discordant therapy | 5 (5%) | 3 (4%) | 2 (11%) | 2.82 (0.44–18.24) | 0.26 | ||
Note there were no cases of patients with the peripheral vascular disease, human immunodeficiency virus, cancer, and receipt of chemotherapy
MRSA methicillin resistant S. aureus, MSSA methicillin susceptible S. aureus, SD standard deviation, OR odds ratio, CI confidence interval, aOR adjusted odds ratio, SSTI skin and soft tissue infection, BMI body mass index, I&D incision and drainage
* Fishers exact test was used