ggsurvplot, displaying time in years instead of days

[kassambara]

(e-mail from a user)

Hi

I continue to use your ggsurvplot and it’s really good, such a good package and nice to see you’re adding features such as the cumulative events table, no. censored subjects – great features!

Anyway, I wonder if there is a way of displaying time in years when it has been calculated in days. For example, I have some overall survival data calculated in days (it’s trivial to recalculate the OS in years), similar to the ‘xscale’ function in base plot.survfit

From the documentation;

https://stat.ethz.ch/R-manual/R-devel/library/survival/html/plot.survfit.html

“
xscale
a numeric value used like yscale for labels on the x axis. A value of 365.25 will give labels in years instead of the original days.
“

I think this would be a useful addition.

[kassambara]

New argument suggestion for x scale transformation

xscale = c("d_m", "d_y", "m_d", "m_y", "y_d", "y_m")

d_m: days to months
d_y: from days to years
m_d: months to days
....

[kassambara]

To be added in ggsurvplot

xscale = "d_m"
xtrans <- switch(xscale,
      d_m = 12/365.25,
      d_y = 1/365.25,
      m_d = 365.25/12,
      m_y = 1/12,
      y_d = 365.25,
      y_m = 12,
      1
      )

breaks <- c(0, 250, 500, 750, 1000)
p + scale_x_continuous(
  breaks = breaks,
  labels = round(breaks*xtrans,2))

[kassambara]

• New argument xscale in ggsurvplot(): numeric or character value specifying x-axis scale.
  • If numeric, the value is used to divide the labels on the x axis. For example, a value of 365.25 will give labels in years instead of the original days.
  • If character, allowed options include one of c("d_m", "d_y", "m_d", "m_y", "y_d", "y_m"), where d = days, m = months and y = years. For example, xscale = "d_m" will transform labels from days to months; xscale = "m_y", will transform labels from months to years

[JuRaGa]

Hi, I am using the flag "d_m" to convert my time scale in days to months. This works, but the months have decimals. I was wondering if there was a way to round them so they display as integers?

Thank you,

[ayc17]

Also having the same issue as my months appear in decimals. For instance, I wanted to see 3, 6, 9, 12 months intervals, but instead it shows up as 3.29, 6.57, 9.86. Is there a way to round them? Thanks!

[nandobonf]

A workaround is to add the argument "break.time.by=365.25*3"