Define Royston & Parmar Spline Survival Distribution — define_surv

Define Royston & Parmar restricted cubic spline parametric survival distribution.

Usage

define_surv_spline(scale, ...)

define_spline_survival(scale, ...)

Arguments

scale: "hazard", "odds", or "normal", as described in flexsurvspline. With the default of no knots in addition to the boundaries, these models reduce to the Weibull, log-logistic and log-normal respectively. The scale must be common to all times.
...: parameters and knot log times of spline distribution, which can be provided either in order starting with spline parameters followed by knot log times, or by names (e.g gamma1, gamma2, ... gammaN, knots1, knots2, ... knotsN). See examples below for named and unnamed calls.

Value

a surv_spline object.

References

Royston, P. and Parmar, M. (2002). Flexible parametric proportional-hazards and proportional-odds models for censored survival data, with application to prognostic modelling and estimation of treatment effects. Statistics in Medicine 21(1):2175-2197.

Examples


define_surv_spline(
 scale = 'hazard',
 -2.08, 2.75, 0.23, # parameters
 -1.62, 0.57, 1.191 # knot times
)
#> A Royston & Parmar spline model of log cumulative hazard with 3 knots (gamma = [-2.08, 2.75, 0.23], knots = [-1.62, 0.57, 1.19]).