Table 4.
Factors Associated With 90-day Mortality in NSTI Caused by GAS
| Univariate Model (n = 125) | Adjusted Modela (n = 125) | Lasso Regressionb (n = 125) | |||
|---|---|---|---|---|---|
| Characteristic | OR | P value | OR | P value | OR |
| Age (years) | 1.06 | .015 | 1.32 | <.0005 | 1.15 |
| Sex (male) | 3.33 | .066 | 145.82 | .002 | 5.09 |
| CVD | 0.69 | .765 | 0.02 | .006 | 0.22 |
| Active malignancy | 0.89 | 1.000 | <0.01 | .008 | 0.04 |
| Septic shockc | 1.93 | .541 | 25.73 | .048 | 1.96 |
| Initial surgery > 24 hours after admissiond | 0.33 | .216 | 0.30 | .422 | 0.95 |
| No clindamycin before inclusione | 0.40 | .342 | 0.06 | .166 | 0.36 |
| IVIG not given | 2.98 | .086 | 7.60 | .125 | 3.15 |
| HBOT not given | 23.81 | <.0005 | 1220.47 | <.0005 | 78.80 |
Abbreviations: CVD, cardiovascular disease (including hypertension and peripheral vascular disease); GAS, group A Streptococcus, Streptococcus pyogenes; HBOT, hyperbaric oxygen treatment; IVIG, treatment with polyspecific immunoglobulin G (any dose); NSTI, necrotizing soft tissue infection; OR, odds ratio.
aLogistic regression analysis.
bLasso regression is a shrinkage method, which gives us a more reliable model by shrinking the coefficient estimates (compared to the logistic model). Variables with little or no predictive value will be shrunken to zero (an OR of 1). P values or confidence intervals can not be calculated (see also Supplementary Methods).
cSeptic shock the first 24 hours after admission to intensive care unit/high-dependency unit, defined as lactate >2 mmol/L and use of vasopressor or inotrope.
dInitial surgery performed >24 hours after the first admission to hospital.
eClindamycin not given before admission to intensive care unit/high-dependency unit of the study hospital.