extract_strata: Extract strata from a tidied survival object
In dgrtwo/drlib: Personal R package of David Robinson

The tidied results of a survival object are in

1	extract_strata(tbl, column, ...)

`tbl`	A table
`column`	Column to extract. Should be of the form `col1=val1, col2=val2, ...`
`...`	Extra arguments passed on to extract, such as `remove` or `convert`.

library(survival)
library(broom)

surv_td <- survfit(Surv(stop - start, status) ~ sex + pcdx,
                    data = mgus1) %>%
  tidy()

surv_td

# Extract into "sex" and "pcdx" columns
surv_fit %>%
  extract_strata(strata)

# Now visualize, separating by strata
library(ggplot2)
surv_fit %>%
  extract_strata(strata) %>%
  ggplot(aes(time, estimate, color = sex)) +
  geom_line() +
  geom_ribbon(aes(ymin = conf.low, ymax = conf.high), alpha = .25) +
  facet_wrap(~ pcdx)