Table 3.
Bivariate analysis of risk factors associated with 30-day mortality
| Variable | All patients, n = 384 (%) | Dead at 30 days, n = 70 (%) | Alive at 30 days, n = 314 (%) | OR | 95% CI | P value |
|---|---|---|---|---|---|---|
| Strain type* | ||||||
| Healthcare associated | 267 (70) | 51 (19) | 216 (81) | Ref. | ||
| Community associated | 117 (30) | 19 (16) | 98 (84) | 0·82 | 0·46–1·46 | 0·57 |
| Ethnicity | ||||||
| Caucasian | 95 (25) | 19 (20) | 76 (80) | Ref. | ||
| Hispanic | 150 (39) | 22 (15) | 128 (85) | 0·69 | 0·35–1·35 | 0·28 |
| African-American | 86 (22) | 15 (17) | 71 (83) | 0·85 | 0·40–1·79 | 0·66 |
| Other | 53 (14) | 14 (26) | 39 (74) | 1·44 | 0·65–3·17 | 0·37 |
| Gender | ||||||
| Female | 126 (33) | 34 (27) | 92 (73) | 2·28 | 1·34–3·86 | 0·003 |
| Male | 258 (67) | 36 (14) | 222 (86) | Ref. | ||
| Age | ||||||
| Mean±s.d. | 51 ± 16 | 61 ± 16 | 49 ± 15 | 1·05 | 1·03–1·06 | <0·0001 |
| Median (range) | 50 (19–97) | 62 (26–97) | 48 (19–88) | |||
| Year of infection | ||||||
| 1999 | 29 (8) | 3 (10) | 26 (90) | 0·95 | 0·21–4·28 | 0·94 |
| 2000 | 42 (11) | 12 (29) | 30 (71) | 3·28 | 1·04–10·30 | 0·04 |
| 2001 | 32 (8) | 5 (16) | 27 (84) | 1·52 | 0·39–5·75 | 0·54 |
| 2002 | 22 (6) | 3 (14) | 19 (86) | 1·30 | 0·28–5·99 | 0·74 |
| 2003 | 32 (8) | 3 (9) | 29 (91) | 0·85 | 0·19–3·83 | 0·83 |
| 2004 | 30 (8) | 8 (27) | 22 (73) | 2·90 | 0·87–10·22 | 0·08 |
| 2005 | 1 (0) | 0 (0) | 1 (100) | — | — | 0·99 |
| 2006 | 34 (9) | 5 (15) | 29 (85) | 1·41 | 0·38–5·33 | 0·61 |
| 2007 | 65 (17) | 16 (25) | 49 (75) | 2·69 | 0·90–7·94 | 0·08 |
| 2008 | 51 (13) | 10 (20) | 41 (80) | 2·00 | 0·63–6·36 | 0·24 |
| 2009 | 46 (12) | 5 (11) | 41 (89) | Ref. | ||
| Length of stay prior to culture collection | ||||||
| Mean±s.d. | 20 ± 27 | 18 ± 15 | 21 ± 29 | 0·99 | 0·98–1·008 | 0·40 |
| Median (range) | 13 (3–400) | 14 (3–77) | 13 (3–400) | |||
| Type of infection | ||||||
| Skin/soft tissue | 133 (35) | 7 (5) | 126 (95) | Ref. | ||
| Blood | 74 (19) | 17 (23) | 57 (77) | 5·37 | 2·11–13·66 | 0·0004 |
| Pneumonia | 131 (34) | 40 (31) | 91 (69) | 7·91 | 3·39–18·46 | <0·0001 |
| Other† | 46 (12) | 6 (13) | 40 (87) | 2·70 | 0·86–8·50 | 0·09 |
| On appropriate anti-MRSA antibiotic at culture | 65 (17) | 15 (23) | 50 (77) | 1·44 | 0·76–2·75 | 0·29 |
| Never treated with an anti-MRSA antibiotic | 38 (10) | 11 (29) | 27 (71) | 1·98 | 0·93–4·21 | 0·08 |
| Charlson Comorbidity Index | ||||||
| Mean±s.d. | 3 ± 3 | 4 ± 3 | 2 ± 3 | 1·20 | 1·09–1·31 | <0·0001 |
| Median (range) | 2 (0–12) | 3 (0–12) | 2 (0–11) | |||
| Cancer | 61 (16) | 15 (25) | 46 (75) | 1·59 | 0·83–3·05 | 0·20 |
| HIV | 9 (2) | 5 (56) | 4 (44) | 6·00 | 1·59–22·81 | 0·01 |
| Diabetes | 116 (30) | 19 (16) | 97 (84) | 0·83 | 0·46–1·49 | 0·57 |
| APACHE II score | ||||||
| Mean±s.d. | 17 ± 11 | 24 ± 9 | 16 ± 11 | 1·07 | 1·04–1·09 | <0·0001 |
| Median (range) | 17 (0–55) | 24 (0–55) | 14 (0–50) | |||
OR, Odds ratio; CI, confidence interval; Ref., reference group.
*
Based on antibiotic susceptibility phenotype (minimum inhibitory concentration susceptible to gentamicin, clindamycin, and trimethoprim-sulfamethoxazole).
†
Other infection type (n = 46) includes 21 urinary tract infections, 19 intra-abdominal infections, and six arterial or venous cardiovascular system infections.