I am trying to create multiple univariate cox regression analyses using GTsummary. However, I need to add a stratification variable into the model and not sure how to go about this. Could any of you kindly help?
I would need to stratify my current working code by a variable "job_site"
#CURRENT CODE:
uvlm_table <- tbl_uvregression(
tbl1 %>%
select(right_censor, n_result, age, exp_case, job_cat, n_facilities)
type = list(
age ~ "continuous"
),
method = coxph,
y = Surv(right_censor, n_result),
exponentiate = TRUE,
pvalue_fun = ~style_pvalue(.x, digits=3)
)
uvlm_table
I tried to write the formula out manually but it did not work.
If you are looking to stratify by job site you can modify the formula
input to incorporate this. I added job site as a strata below.
library(survival)
library(gtsummary)
uvlm_table <- tbl_uvregression(
tbl1 %>%
select(right_censor, n_result, age, exp_case, job_cat, n_facilities, job_site),
type = list(
age ~ "continuous"
),
method = coxph,
y = Surv(right_censor, n_result),
formula = "{y} ~ {x} + strata(job_site)",
exponentiate = TRUE,
pvalue_fun = ~style_pvalue(.x, digits=3)
)
Here is a reproducible example with the trial dataset from gtsummary
.
uvlm_table <- tbl_uvregression(
trial %>%
select(ttdeath, death, age,marker, grade),
type = list(
age ~ "continuous"
),
method = coxph,
y = Surv(ttdeath, death),
formula = "{y} ~ {x} + strata(grade)",
exponentiate = TRUE,
pvalue_fun = ~style_pvalue(.x, digits=3)
)