A severity score for complicated skin and soft tissue infections derived from phase III studies of linezolid.
BACKGROUND
Severity scoring systems are useful for assessing patient risk and predicting prognosis.


METHODS
We developed a scoring system using data from a phase III study comparing antibiotics in hospitalized patients with complicated skin and soft tissue infections (study A), and used logistic regression analysis to identify factors contributing to treatment failure. We tested this system using data from a similar study (study B).


RESULTS
In study A (n = 682), cure rates were lower in patients with at least 1 comorbid condition (P <0.05) and in the highest risk class (P = 0.05); elevated blood urea nitrogen, hyponatremia, anemia, lesion size, and surgical wound infection were independent predictors of failure (P <0.05). In study B (n = 166), findings were similar and significant for risk class (P <0.05). In the combined analysis (n = 848), cure rates were higher for linezolid than for the comparator in all patients (85% versus 77%; P <0.01) and in subanalyses by comorbid conditions, median score, and risk class (P <0.05).


CONCLUSIONS
We developed and validated a scoring system in which baseline variables predicted outcome. Patients with higher severity scores generally had poorer outcomes regardless of treatment group. Our finding that linezolid was an independent predictor of cure merits further evaluation.
Wilson
Samuel Eric
SE
Department of Surgery, University of California Irvine, UCI Medical Center, 101 The City Dr., South Orange, CA 92868, USA. wilsonse@uct.edu
Solomkin
Joseph S
JS
Le
Vu
V
Cammarata
Sue K
SK
Bruss
Jon B
JB
D000081:Acetamides / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D000890:Anti-Infective Agents / Q000627:therapeutic use*; D017326:Clinical Trials, Phase III as Topic; D003023:Cloxacillin / Q000627:therapeutic use; D005260:Female; D006801:Humans; D000069349:Linezolid; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D023303:Oxazolidinones / Q000627:therapeutic use*; D010406:Penicillins / Q000627:therapeutic use; D011379:Prognosis; D012306:Risk; D012720:Severity of Illness Index; D017192:Skin Diseases, Bacterial / Q000175:diagnosis / Q000188:drug therapy*; D018461:Soft Tissue Infections / Q000188:drug therapy*; D017211:Treatment Failure
D000081:Acetamides; D000890:Anti-Infective Agents; D023303:Oxazolidinones; D010406:Penicillins; D000069349:Linezolid; D003023:Cloxacillin