invtime function

Inverse transforming of time in Relative Survival

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.

invtime(
  y = 0.1,
  age = 23011,
  sex = "male",
  year = as.Date("1986-01-01"),
  scale = 1,
  ratetable = relsurv::slopop,
  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 or POSIXt 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.

Returns

A list of values - T: the original time - Y: the transformed time.

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.

Examples

data(slopop)
invtime(y = 0.1, age = 23011, sex = 1, year = as.Date('1986-01-01'), ratetable = slopop)

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