The authors are from Massachusetts General Hospital, Brigham and Women's Hospital and Loyola University in Chicago.
Patient selection: lower extremity skin lesion suggestive of cellulitis
Parameters:
(1) asymmetry skin findings (A)
(2) leukocytosis (white blood cell count per µL) (L)
(3) tachycardia (heart rate in beats per minute, bpm) (T)
(4) age in years (70)
|
Parameters
|
Findings
|
Points
|
Beta Coefficient
|
|
asymmetric skin findings
|
no
|
0
|
0
|
|
|
yes
|
3
|
2.1574
|
|
WBC count
|
< 10,000 per µL
|
0
|
0
|
|
|
>= 10,000 per µL
|
1
|
0.8891
|
|
heart rate
|
< 90 bpm
|
0
|
0
|
|
|
>= 90 bpm
|
1
|
0.6606
|
|
age in years
|
< 70 years
|
0
|
0
|
|
|
>= 70 years
|
2
|
0.9952
|
total score =
= SUM(points for all 4 parameters)
X =
= SUM(beta-coefficients) - 2.0096
probability of cellulitis =
= 1 / (1 + EXP((-1) * X))
Interpretation:
• minimum score: 0
• maximum score: 7
• The higher the score the greater the risk of cellulitis.
• A score >= 5 had a >= 82% likelihood of true cellulitis.
• A score <= 2 had a >= 83% likelihood of pseudocellultis.
Performance:
• The area under the ROC curve is 0.75.
