|Introduction to Survival Analysis Procedures
The PHREG Procedure
The PHREG procedure fits the proportional hazards model of
Cox (1972, 1975) to survival
data that may be right censored. The Cox model is a semiparametric
model in which the hazard function of the survival time is
where h0(t) is an unspecified baseline hazard function,
x(t) is a vectors of covariate values, possibly
time-dependent, and is a vector of unknown regression
model is referred to as a semiparametric model since part of the
model involves the unspecified baseline function over time (which
is infinite dimensional) and the other part involves a finite number
of regression parameters. Several texts that discuss the Cox
are Collett (1994), Cox and Oaks (1984), Lawless (1982), Kalbfleish
and Prentice (1980).
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