tbl_svysummary {gtsummary}

Create a table of summary statistics from a survey object

Description

The tbl_svysummary() function calculates descriptive statistics for continuous, categorical, and dichotomous variables taking into account survey weights and design.

Usage

tbl_svysummary(
  data,
  by = NULL,
  label = NULL,
  statistic = list(all_continuous() ~ "{median} ({p25}, {p75})", all_categorical() ~
    "{n} ({p}%)"),
  digits = NULL,
  type = NULL,
  value = NULL,
  missing = c("ifany", "no", "always"),
  missing_text = "Unknown",
  missing_stat = "{N_miss}",
  sort = all_categorical(FALSE) ~ "alphanumeric",
  percent = c("column", "row", "cell"),
  include = everything()
)

Arguments

data

(survey.design)
A survey object created with created with survey::svydesign()

by

(tidy-select)
A single column from data. Summary statistics will be stratified by this variable. Default is NULL.

label

(formula-list-selector)
Used to override default labels in summary table, e.g. list(age = "Age, years"). The default for each variable is the column label attribute, attr(., 'label'). If no label has been set, the column name is used.

statistic

(formula-list-selector)
Specifies summary statistics to display for each variable. The default is list(all_continuous() ~ "{median} ({p25}, {p75})", all_categorical() ~ "{n} ({p}%)"). See below for details.

digits

(formula-list-selector)
Specifies how summary statistics are rounded. Values may be either integer(s) or function(s). If not specified, default formatting is assigned via assign_summary_digits(). See below for details.

type

(formula-list-selector)
Specifies the summary type. Accepted value are c("continuous", "continuous2", "categorical", "dichotomous"). If not specified, default type is assigned via assign_summary_type(). See below for details.

value

(formula-list-selector)
Specifies the level of a variable to display on a single row. The gtsummary type selectors, e.g. all_dichotomous(), cannot be used with this argument. Default is NULL. See below for details.

missing, missing_text, missing_stat

Arguments dictating how and if missing values are presented:

• missing: must be one of c("ifany", "no", "always")

• missing_text: string indicating text shown on missing row. Default is "Unknown"

• missing_stat: statistic to show on missing row. Default is "{N_miss}". Possible values are N_miss, N_obs, N_nonmiss, p_miss, p_nonmiss.

sort

(formula-list-selector)
Specifies sorting to perform for categorical variables. Values must be one of c("alphanumeric", "frequency"). Default is all_categorical(FALSE) ~ "alphanumeric".

percent

(string)
Indicates the type of percentage to return. Must be one of c("column", "row", "cell"). Default is "column".

include

(tidy-select)
Variables to include in the summary table. Default is everything().

Value

A 'tbl_svysummary' object

statistic argument

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} proportion

• {p.std.error} standard error of the sample proportion computed with survey::svymean()

• {deff} design effect 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

• {mean.std.error} standard error of the sample mean computed with survey::svymean()

• {deff} design effect of the sample mean computed with survey::svymean()

• {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.

type and value arguments

There are four summary types. Use the type argument to change the default 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")

Author(s)

Joseph Larmarange

Examples

# Example 1 ----------------------------------
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")
survey::svydesign(id = ~dnum, weights = ~pw, data = apiclus1, fpc = ~fpc) |>
  tbl_svysummary(by = "both", include = c(api00, stype)) |>
  modify_spanning_header(all_stat_cols() ~ "**Survived**")