Proportion difference and confidence interval

Function for calculating the proportion (or risk) difference and confidence interval between arm X (reference group) and arm Y. Risk difference is calculated by subtracting cumulative incidence in arm Y from cumulative incidence in arm X.

Usage

stat_propdiff_ci(
  x,
  y,
  N_x,
  N_y,
  list_names = NULL,
  conf_level = 0.95,
  pct = TRUE
)

Arguments

x

(list of integer)
list of number of occurrences in arm X (reference group).

y

(list of integer)
list of number of occurrences in arm Y. Must be of equal length to x.

N_x

(numeric(1))
total number of records in arm X.

N_y

(numeric(1))
total number of records in arm Y.

list_names

(character)
names of each variable/level corresponding to pair of proportions in x and y. Must be of equal length to x and y.

conf_level

(proportion)
confidence level of the interval.

pct

(flag)
whether output should be returned as percentages. Defaults to TRUE.

Value

List of proportion differences and CIs corresponding to each pair of number of occurrences in x and y. Each list element consists of 3 statistics: proportion difference, CI lower bound, and CI upper bound.

See also

Split function add_riskdiff() which, when used as split_fun within rtables::split_cols_by() with riskdiff argument is set to TRUE in subsequent analyze functions, adds a column containing proportion (risk) difference to an rtables layout.

Examples

stat_propdiff_ci(
  x = list(0.375), y = list(0.01), N_x = 5, N_y = 5, list_names = "x", conf_level = 0.9
)
#> $x
#> [1]   7.30000 -12.35184  26.95184
#> 

stat_propdiff_ci(
  x = list(0.5, 0.75, 1), y = list(0.25, 0.05, 0.5), N_x = 10, N_y = 20, pct = FALSE
)
#> [[1]]
#> [1]  0.0375000 -0.1060891  0.1810891
#> 
#> [[2]]
#> [1]  0.07250000 -0.09220915  0.23720915
#> 
#> [[3]]
#> [1]  0.0750000 -0.1231285  0.2731285
#>