Total IE Mortality Risk Score = sum of weighted predictors:

Domain	Predictor	Points
Host factors	Age ≤45 years	0
Host factors	Age 46–60 years	+2
Host factors	Age 61–70 years	+3
Host factors	Age >70 years	+4
Host factors	History of dialysis	+3
IE factors	Nosocomial IE	+2
IE factors	Prosthetic valve IE	+1
IE factors	Symptoms >1 month before admission	−1
IE factors	Staphylococcus aureus as causative organism	+1
IE factors	Viridans group streptococci as causative organism	−2
IE factors	Aortic valve vegetation	+1
IE factors	Mitral valve vegetation	+1
IE complications	NYHA class III or IV heart failure due to IE	+3
IE complications	Stroke	+2
IE complications	Paravalvular complication (e.g. abscess, pseudoaneurysm, fistula)	+2
IE complications	Persistent bacteraemia	+2
Treatment	Surgical treatment for this IE episode	−2

Approximate 6-month mortality (%) can then be estimated from the total score using the quadratic relation:
Probability of 6-month mortality (%) = 2.4169 × score + 0.1099 × score² − 4.849.
This relation was calibrated for scores between 0 and 22; values outside this range should be interpreted with caution.

Infective Endocarditis (IE) Mortality Risk Score