Wiseman et al reported the HIV Surgical Mortality Score (HSMS) for HIV-positive patients. This can help to identify a patient who may benefit from more aggressive management. The authors are from the University of British Columbia and Simon Fraser University.
Patient selection: HIV-positive adult undergoing surgery
Outcome: 30-day mortality
Parameters:
(1) age of the patient
(2) timing of surgery
(3) history of prior surgery within the past 6 months
(4) absolute CD4 count per µL
(5) hemoglobin concnetration in g/L
(6) white blood cell count (given as g/L but 10^9/L seems more plausible for a count)
|
Parameter
|
Finding
|
Points
|
|
age of the patient
|
|
6 * (age)
|
|
timing of surgery
|
elective
|
0
|
|
|
urgent or emergency
|
1.02
|
|
history of previous surgery
|
no
|
0
|
|
|
more than 6 months ago
|
-0.37
|
|
|
<= 6 months
|
0.70
|
|
absolute CD4
|
> 200 per µL
|
0
|
|
|
51 to 200 per µL
|
0.59
|
|
|
<= 50
|
0.99
|
|
hemoglobin
|
> 120 g/L
|
0
|
|
|
<= 120 g/L
|
1.53
|
|
white blood cell count
|
<= 11 * 10^9/L
|
0
|
|
|
> 11 * 10^9/L
|
1.74
|
where:
• Laboratory specimens were taken in the 90 days before surgery.
NOTE: Using the reported "6 * (age)" gives false results. The LN of 1.83 is 0.6 and the odds ratio for age should be for every 10 years. Therefore, the proper term may be "0.06 * (age)".
X =
= SUM(points for all 6 parameters) - 7.60
probability of 30 day mortality =
= 1 / (1+EXP((-1) * X))
Performance:
• The area under the ROC curve is reported as 0.85.
