# Table 3 Components of the FAB prediction model

Variable Type   Equation factor
Age Numeric (Years)   0.041
Activin A, Activin B measurement at 2 days after commencement of ventilation – FAB Constructed variable Choice Activin A <0.283 ng/mL 0
Activin B <0.156 ng/mL
Activin A >0.283 ng/mL OR 0.934
Activin B >0.156 ng/mL
Activin A >0.283 ng/mL AND 1.197
Activin B >0.156 ng/mL
Chronic restrictive pulmonary disease Yes/No Yes 0.900
Chronic obstructive pulmonary disease Yes/No Yes 0.577
Diagnostic group Choice Postoperative cardiovascular 0
Postoperative gastrointestinal 1.505
Non-operative cardiovascular 2.135
Non-operative sepsis 0.959
Non-operative Gastrointestinal/hematological 1.111
Non-operative metabolic 1.796
Non-operative neurologic 2.599
Non-operative respiratory 1.824
Non-operative trauma 0.720
Miscellaneous postoperative (respiratory, gynecologic, renal, orthopedic) 1.265
SOFA maximal score Numeric   0.220
Constant    -7.765
1. FAB, follistatin, and activin A and B; SOFA: Sequential Organ Failure Assessment. Formula for FAB score: (Age*0.041) + (Activin A/B component) + (Presence of xhronic restrictive pulmonary disease) + (Presence of chronic obstructive pulmonary disease) + (Diagnostic group) + (Maximal SOFA score*0.220) + Constant. This produces a range with a mean of zero. To obtain the risk profile, each value was entered into the following equation:$Probability Estimate = ln Result 1 + ln Result$.
2. This produced a range of values from 0.0 to 1.0, a score approaching 1.0 having the greatest risk of death and approaching 0.0 having the least risk of death. For risk stratification purposes, it was then divided into 10 bins, each 0.1 wide with the upper endpoint of each bin included in the lower bin.
3. The equation factor listed is the value that should be inserted into the equation.