invtime {relsurv}

Inverse transforming of time in Relative Survival

Description

This function can be used when predicting in Relative Survival using the transformed time regression model (using rstrans function). It inverses the time from Y to T in relative survival using the given ratetable. The times Y can be produced with the rstrans function, in which case, this is the reverse function. This function does the transformation for one person at a time.

Usage

invtime(y, age, sex, year, scale, ratetable, lower, upper)

Arguments

y

time in Y.

age

age of the individual. Must be in days.

sex

sex of the individual. Must be coded in the same way as in the ratetable.

year

date of diagnosis. Must be in a date format

scale

numeric value to scale the results. If ratetable is in units/day, scale = 365.241 causes the output to be reported in years.

ratetable

a table of event rates, such as survexp.us.

lower

the lower bound of interval where the result is expected. This argument is optional, but, if given, can shorten the time the function needs to calculate the result.

upper

the upper bound of interval where the result is expected. See lower

Details

Works only with ratetables that are split by age, sex and year. Transforming can be computationally intensive, use lower and/or upper to guess the interval of the result and thus speed up the function.

Value

A list of values

T

the original time

Y

the transformed time

References

Package: Pohar M., Stare J. (2006) "Relative survival analysis in R." Computer Methods and Programs in Biomedicine, 81: 272-278.

Relative survival: Pohar, M., Stare, J. (2007) "Making relative survival analysis relatively easy." Computers in biology and medicine, 37: 1741-1749.

See Also

rstrans

Examples

data(slopop)
invtime(y = 0.1, age = 23011, sex = 1, year = 9497, ratetable = slopop)