estimate_proportion: Proportion estimation

In tern: Create Common TLGs Used in Clinical Trials

Proportion estimation

Description

The analyze function estimate_proportion() creates a layout element to estimate the proportion of responders within a studied population. The primary analysis variable, vars, indicates whether a response has occurred for each record. See the method parameter for options of methods to use when constructing the confidence interval of the proportion. Additionally, a stratification variable can be supplied via the strata element of the variables argument.

Usage

estimate_proportion(
  lyt,
  vars,
  conf_level = 0.95,
  method = c("waldcc", "wald", "clopper-pearson", "wilson", "wilsonc", "strat_wilson",
    "strat_wilsonc", "agresti-coull", "jeffreys"),
  weights = NULL,
  max_iterations = 50,
  variables = list(strata = NULL),
  long = FALSE,
  na_str = default_na_str(),
  nested = TRUE,
  ...,
  show_labels = "hidden",
  table_names = vars,
  .stats = NULL,
  .formats = NULL,
  .labels = NULL,
  .indent_mods = NULL
)

s_proportion(
  df,
  .var,
  conf_level = 0.95,
  method = c("waldcc", "wald", "clopper-pearson", "wilson", "wilsonc", "strat_wilson",
    "strat_wilsonc", "agresti-coull", "jeffreys"),
  weights = NULL,
  max_iterations = 50,
  variables = list(strata = NULL),
  long = FALSE
)

a_proportion(
  df,
  .var,
  conf_level = 0.95,
  method = c("waldcc", "wald", "clopper-pearson", "wilson", "wilsonc", "strat_wilson",
    "strat_wilsonc", "agresti-coull", "jeffreys"),
  weights = NULL,
  max_iterations = 50,
  variables = list(strata = NULL),
  long = FALSE
)

Arguments

lyt	(PreDataTableLayouts) layout that analyses will be added to.
vars	(character) variable names for the primary analysis variable to be iterated over.
conf_level	(proportion) confidence level of the interval.
method	(string) the method used to construct the confidence interval for proportion of successful outcomes; one of waldcc, wald, clopper-pearson, wilson, wilsonc, strat_wilson, strat_wilsonc, agresti-coull or jeffreys.
weights	(numeric or NULL) weights for each level of the strata. If NULL, they are estimated using the iterative algorithm proposed in \insertCiteYan2010-jt;textualtern that minimizes the weighted squared length of the confidence interval.
max_iterations	(count) maximum number of iterations for the iterative procedure used to find estimates of optimal weights.
variables	(named list of string) list of additional analysis variables.
long	(flag) whether a long description is required.
na_str	(string) string used to replace all NA or empty values in the output.
nested	(flag) whether this layout instruction should be applied within the existing layout structure _if possible (TRUE, the default) or as a new top-level element (FALSE). Ignored if it would nest a split. underneath analyses, which is not allowed.
...	additional arguments for the lower level functions.
show_labels	(string) label visibility: one of "default", "visible" and "hidden".
table_names	(character) this can be customized in the case that the same vars are analyzed multiple times, to avoid warnings from rtables.
.stats	(character) statistics to select for the table. Run get_stats("estimate_proportion") to see available statistics for this function.
.formats	(named character or list) formats for the statistics. See Details in analyze_vars for more information on the "auto" setting.
.labels	(named character) labels for the statistics (without indent).
.indent_mods	(named integer) indent modifiers for the labels. Defaults to 0, which corresponds to the unmodified default behavior. Can be negative.
df	(logical or data.frame) if only a logical vector is used, it indicates whether each subject is a responder or not. TRUE represents a successful outcome. If a data.frame is provided, also the strata variable names must be provided in variables as a list element with the strata strings. In the case of data.frame, the logical vector of responses must be indicated as a variable name in .var.
.var	(string) single variable name that is passed by rtables when requested by a statistics function.

Value

• estimate_proportion() returns a layout object suitable for passing to further layouting functions, or to rtables::build_table(). Adding this function to an rtable layout will add formatted rows containing the statistics from s_proportion() to the table layout.

• s_proportion() returns statistics n_prop (n and proportion) and prop_ci (proportion CI) for a given variable.

• a_proportion() returns the corresponding list with formatted rtables::CellValue().

Functions

• estimate_proportion(): Layout-creating function which can take statistics function arguments and additional format arguments. This function is a wrapper for rtables::analyze().

• s_proportion(): Statistics function estimating a proportion along with its confidence interval.

• a_proportion(): Formatted analysis function which is used as afun in estimate_proportion().

See Also

h_proportions

Examples

dta_test <- data.frame(
  USUBJID = paste0("S", 1:12),
  ARM     = rep(LETTERS[1:3], each = 4),
  AVAL    = rep(LETTERS[1:3], each = 4)
)

basic_table() %>%
  split_cols_by("ARM") %>%
  estimate_proportion(vars = "AVAL") %>%
  build_table(df = dta_test)

# Case with only logical vector.
rsp_v <- c(1, 0, 1, 0, 1, 1, 0, 0)
s_proportion(rsp_v)

# Example for Stratified Wilson CI
nex <- 100 # Number of example rows
dta <- data.frame(
  "rsp" = sample(c(TRUE, FALSE), nex, TRUE),
  "grp" = sample(c("A", "B"), nex, TRUE),
  "f1" = sample(c("a1", "a2"), nex, TRUE),
  "f2" = sample(c("x", "y", "z"), nex, TRUE),
  stringsAsFactors = TRUE
)

s_proportion(
  df = dta,
  .var = "rsp",
  variables = list(strata = c("f1", "f2")),
  conf_level = 0.90,
  method = "strat_wilson"
)

tern documentation built on Sept. 24, 2024, 9:06 a.m.