The tbl_svysummary
function calculates descriptive statistics for
continuous, categorical, and dichotomous variables taking into account survey weights and design.
It is similar to tbl_summary()
.
tbl_svysummary(
data,
by = NULL,
label = NULL,
statistic = NULL,
digits = NULL,
type = NULL,
value = NULL,
missing = NULL,
missing_text = NULL,
sort = NULL,
percent = NULL,
include = everything()
)
A tbl_svysummary
object
The statistic argument specifies the statistics presented in the table. The
input is a list of formulas that specify the statistics to report. For example,
statistic = list(age ~ "{mean} ({sd})")
would report the mean and
standard deviation for age; statistic = list(all_continuous() ~ "{mean} ({sd})")
would report the mean and standard deviation for all continuous variables.
A statistic name that appears between curly brackets
will be replaced with the numeric statistic (see glue::glue).
For categorical variables the following statistics are available to display.
{n}
frequency
{N}
denominator, or cohort size
{p}
percentage
{p.std.error}
standard error of the sample proportion computed with survey::svymean()
{n_unweighted}
unweighted frequency
{N_unweighted}
unweighted denominator
{p_unweighted}
unweighted formatted percentage
For continuous variables the following statistics are available to display.
{median}
median
{mean}
mean
{sd}
standard deviation
{var}
variance
{min}
minimum
{max}
maximum
{p##}
any integer percentile, where ##
is an integer from 0 to 100
{sum}
sum
Unlike tbl_summary()
, it is not possible to pass a custom function.
For both categorical and continuous variables, statistics on the number of missing and non-missing observations and their proportions are available to display.
{N_obs}
total number of observations
{N_miss}
number of missing observations
{N_nonmiss}
number of non-missing observations
{p_miss}
percentage of observations missing
{p_nonmiss}
percentage of observations not missing
{N_obs_unweighted}
unweighted total number of observations
{N_miss_unweighted}
unweighted number of missing observations
{N_nonmiss_unweighted}
unweighted number of non-missing observations
{p_miss_unweighted}
unweighted percentage of observations missing
{p_nonmiss_unweighted}
unweighted percentage of observations not missing
Note that for categorical variables, {N_obs}
, {N_miss}
and {N_nonmiss}
refer
to the total number, number missing and number non missing observations
in the denominator, not at each level of the categorical variable.
Example 1
Example 2
The tbl_summary()
function has four summary types:
"continuous"
summaries are shown on a single row. Most numeric
variables default to summary type continuous.
"continuous2"
summaries are shown on 2 or more rows
"categorical"
multi-line summaries of nominal data. Character variables,
factor variables, and numeric variables with fewer than 10 unique levels default to
type categorical. To change a numeric variable to continuous that
defaulted to categorical, use type = list(varname ~ "continuous")
"dichotomous"
categorical variables that are displayed on a single row,
rather than one row per level of the variable.
Variables coded as TRUE
/FALSE
, 0
/1
, or yes
/no
are assumed to be dichotomous,
and the TRUE
, 1
, and yes
rows are displayed.
Otherwise, the value to display must be specified in the value
argument, e.g. value = list(varname ~ "level to show")
Select helpers
from the \tidyselect\ package and \gtsummary\ package are available to
modify default behavior for groups of variables.
For example, by default continuous variables are reported with the median
and IQR. To change all continuous variables to mean and standard deviation use
statistic = list(all_continuous() ~ "{mean} ({sd})")
.
All columns with class logical are displayed as dichotomous variables showing
the proportion of events that are TRUE
on a single row. To show both rows
(i.e. a row for TRUE
and a row for FALSE
) use
type = list(where(is.logical) ~ "categorical")
.
The select helpers are available for use in any argument that accepts a list
of formulas (e.g. statistic
, type
, digits
, value
, sort
, etc.)
Read more on the syntax used through the package.
Review list, formula, and selector syntax used throughout gtsummary
Other tbl_svysummary tools:
add_n.tbl_summary()
,
add_overall()
,
add_p.tbl_svysummary()
,
add_q()
,
add_stat_label()
,
modify
,
separate_p_footnotes()
,
tbl_merge()
,
tbl_split()
,
tbl_stack()
,
tbl_strata()
# NOT RUN {
# A simple weighted dataset
tbl_svysummary_ex1 <-
survey::svydesign(~1, data = as.data.frame(Titanic), weights = ~Freq) %>%
tbl_svysummary(by = Survived, percent = "row", include = c(Class, Age))
# Example 2 ----------------------------------
# A dataset with a complex design
data(api, package = "survey")
tbl_svysummary_ex2 <-
survey::svydesign(id = ~dnum, weights = ~pw, data = apiclus1, fpc = ~fpc) %>%
tbl_svysummary(by = "both", include = c(api00, stype))
# }
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