Survival Models of Rieves et al for a Patient with Severe COPD and Acute Respiratory Failure

Patient selection: severe COPD with acute respiratory failure

Parameters at the time of tracheal intubation:

(1) pulmonary infiltrate on chest X-ray (0 if absent, 1 if present)

(2) serum albumin in g/dL

(3) FEV1 in liters

X =

= (-2.2211 * (albumin)) + (5.9265 * (points for pulmonary infiltrate)) + 3.6947

probability of nonsurvival =

= 1 / (1 + EXP((-1) * X))

Y =

= (-1.7851 * (points for pulmonary infiltrate) * (FEV1)) + (5.7065 * (points for pulmonary infiltrate)) - 2.5257

probability of nonsurvival =

= 1 / (1 + EXP((-1) * Y))

Z =

= 5.7065 - (1.7851 * (FEV1))

mortality risk ratio (relative risk) for nonsurvival in those with

infiltrates relative to those without infiltrates =

= EXP(Z)