Score of Steyerberg et al for Predicting Operative Mortality After Elective Repair of an Abdominal Aortic Aneurysm (Leiden Score)

NOTE: I don't think these rates apply to endoluminal repair.

Parameters:

(1) surgeon or center-specific average operative mortality

(2) age of the patient in years

(3) gender of the patient

(4) cardiac comorbidity, based on myocardial infarction, congestive heart failure and ECG evidence of ischemia (ST segment depression > 2 mm)

(5) renal comorbidity

(6) pulmonary comorbidity

where:

• Points for age is assigned with 1 point change for every 2.5 years (page 2002). I am not sure if this extends below 60 years or above 80 years. In the implementation I left them fixed at –4 and +4 respectively.

• If the surgeon's/center's mortality from 5% to 12% is placed in JMP, the following equation fits the data:

points for surgeon's/center's mortality rate =

= (-0.0618 * ((surgeon's percent as a whole number)^2)) + (2.4672 * (surgeon's percent as a whole number)) – 10.7129

total score =

= SUM(points for all 6 parameters)

Interpretation:

• minimum score: -9

• maximum score: 56

• The higher the score the greater the risk of mortality.

An equation approximating this data derived in JMP:

probability of mortality =

= (0.0003497 * ((score)^3)) + (0.013613 * ((score)^2)) + (0.140909 * (score)) + 1.697436