Analysis results data for paired and non-paired t-tests.
Arguments
- data
(
data.frame
)
a data frame. See below for details.- by
(
tidy-select
)
column name to compare by- variable
(
tidy-select
)
column name to be compared- ...
arguments passed to
t.test(...)
- id
(
tidy-select
)
column name of the subject or participant ID
Details
For the ard_ttest()
function, the data is expected to be one row per subject.
The data is passed as t.test(data[[variable]] ~ data[[by]], paired = FALSE, ...)
.
For the ard_paired_ttest()
function, the data is expected to be one row
per subject per by level. Before the t-test is calculated, the data are
reshaped to a wide format to be one row per subject.
The data are then passed as
t.test(x = data_wide[[<by level 1>]], y = data_wide[[<by level 2>]], paired = TRUE, ...)
.
Examples
cards::ADSL |>
dplyr::filter(ARM %in% c("Placebo", "Xanomeline High Dose")) |>
ard_ttest(by = ARM, variable = AGE)
#> {cards} data frame: 11 x 9
#> group1 variable context stat_name stat_label stat
#> 1 ARM AGE ttest estimate Mean Dif… 0.828
#> 2 ARM AGE ttest estimate1 Group 1 … 75.209
#> 3 ARM AGE ttest estimate2 Group 2 … 74.381
#> 4 ARM AGE ttest statistic t Statis… 0.655
#> 5 ARM AGE ttest p.value p-value 0.513
#> 6 ARM AGE ttest parameter Degrees … 167.362
#> 7 ARM AGE ttest conf.low CI Lower… -1.668
#> 8 ARM AGE ttest conf.high CI Upper… 3.324
#> 9 ARM AGE ttest method method Welch Tw…
#> 10 ARM AGE ttest alternative alternat… two.sided
#> 11 ARM AGE ttest paired Paired t… FALSE
#> ℹ 3 more variables: fmt_fn, warning, error
# constructing a paired data set,
# where patients receive both treatments
cards::ADSL[c("ARM", "AGE")] |>
dplyr::filter(ARM %in% c("Placebo", "Xanomeline High Dose")) |>
dplyr::mutate(.by = ARM, USUBJID = dplyr::row_number()) |>
dplyr::arrange(USUBJID, ARM) |>
ard_paired_ttest(by = ARM, variable = AGE, id = USUBJID)
#> {cards} data frame: 9 x 9
#> group1 variable context stat_name stat_label stat
#> 1 ARM AGE ttest estimate Mean Dif… 0.798
#> 2 ARM AGE ttest statistic t Statis… 0.628
#> 3 ARM AGE ttest p.value p-value 0.531
#> 4 ARM AGE ttest parameter Degrees … 83
#> 5 ARM AGE ttest conf.low CI Lower… -1.727
#> 6 ARM AGE ttest conf.high CI Upper… 3.322
#> 7 ARM AGE ttest method method Paired t…
#> 8 ARM AGE ttest alternative alternat… two.sided
#> 9 ARM AGE ttest paired Paired t… TRUE
#> ℹ 3 more variables: fmt_fn, warning, error