Generates a textual summary of a group sequential design using the AHR method.

Usage

text_summary(x, information = FALSE, time_unit = "months")

Arguments

x: A design object created by gs_design_ahr() with or without to_integer().
information: A logical value indicating whether to include statistical information in the textual summary. Default is FALSE.
time_unit: A character string specifying the time unit used in the design. Options include "days", "weeks", "months" (default), and "years".

Value

A character string containing a paragraph that summarizes the design.

Examples

library(gsDesign)

# Text summary of a 1-sided design
x <- gs_design_ahr(info_frac = 1:3/3, test_lower = FALSE)
x %>% text_summary()
#> [1] "One-sided group sequential design with 3 analyses, time-to-event outcome with sample size 489.9 and 300.4 events, 90 percent power, 2.5 percent (1-sided) Type I error to detect hazard ratio of 0.9 during the first 3 months and 0.6 thereafter. Enrollment and total study durations are assumed to be 14 and 36 months, respectively. Efficacy bounds derived using a Lan-DeMets O'Brien-Fleming approximation spending function (no parameters)."
x %>% to_integer() %>% text_summary()
#> [1] "One-sided group sequential design with 3 analyses, time-to-event outcome with sample size 490 and 301 events, 90 percent power, 2.5 percent (1-sided) Type I error to detect hazard ratio of 0.9 during the first 3 months and 0.6 thereafter. Enrollment and total study durations are assumed to be 14 and 36.1 months, respectively. Efficacy bounds derived using a Lan-DeMets O'Brien-Fleming approximation spending function (no parameters)."
gs_power_ahr(event = c(10, 20, 30), test_lower = FALSE) %>% text_summary()
#> [1] "One-sided group sequential design with 3 analyses, time-to-event outcome with sample size 108 and 30 events, 2.5 percent (1-sided) Type I error. Enrollment and total study durations are assumed to be 14 and 14.9 months, respectively. Efficacy bounds derived using a Lan-DeMets O'Brien-Fleming approximation spending function (no parameters). With hazard ratio of 0.9 during the first 3 months and 0.6 thereafter, the power is 9 percent."
gs_power_ahr(event = c(10, 20, 30), test_lower = FALSE) %>% to_integer() %>% text_summary()
#> [1] "One-sided group sequential design with 3 analyses, time-to-event outcome with sample size 108 and 30 events, 2.5 percent (1-sided) Type I error. Enrollment and total study durations are assumed to be 14 and 14.9 months, respectively. Efficacy bounds derived using a Lan-DeMets O'Brien-Fleming approximation spending function (no parameters). With hazard ratio of 0.9 during the first 3 months and 0.6 thereafter, the power is 9 percent."

# Text summary of a 2-sided symmetric design
x <- gs_design_ahr(info_frac = 1:3/3,
                   upper = gs_spending_bound, lower = gs_spending_bound,
                   upar = list(sf = sfLDOF, total_spend = 0.025),
                   lpar = list(sf = sfLDOF, total_spend = 0.025),
                   binding = TRUE, h1_spending = FALSE) %>% to_integer()
x %>% text_summary()
#> [1] "Symmetric two-sided group sequential design with 3 analyses, time-to-event outcome with sample size 490 and 301 events, 90 percent power, 2.5 percent (1-sided) Type I error to detect hazard ratio of 0.9 during the first 3 months and 0.6 thereafter. Enrollment and total study durations are assumed to be 14 and 36.1 months, respectively. Bounds derived using a  Lan-DeMets O'Brien-Fleming approximation spending function (no parameters)."

# Text summary of a asymmetric 2-sided design with beta-spending and non-binding futility bound
x <- gs_design_ahr(info_frac = 1:3/3, alpha = 0.025, beta = 0.1,
                   upper = gs_spending_bound, lower = gs_spending_bound,
                   upar = list(sf = sfLDOF, total_spend = 0.025),
                   lpar = list(sf = sfHSD, total_spend = 0.1, param = -4),
                   binding = FALSE, h1_spending = TRUE) %>% to_integer()
x %>% text_summary()
#> [1] "Asymmetric two-sided group sequential design with non-binding futility bound, 3 analyses, time-to-event outcome with sample size 500 and 306 events, 90 percent power, 2.5 percent (1-sided) Type I error to detect hazard ratio of 0.9 during the first 3 months and 0.6 thereafter. Enrollment and total study durations are assumed to be 14 and 35.9 months, respectively. Efficacy bounds derived using a Lan-DeMets O'Brien-Fleming approximation spending function (no parameters). Futility bounds derived using a Hwang-Shih-DeCani spending function with gamma = -4."

# Text summary of a asymmetric 2-sided design with fixed non-binding futility bound
x <- gs_design_ahr(info_frac = 1:3/3, alpha = 0.025, beta = 0.1,
                   upper = gs_spending_bound, lower = gs_b,
                   upar = list(sf = sfLDOF, total_spend = 0.025),
                   test_upper = c(FALSE, TRUE, TRUE),
                   lpar = c(-1, -Inf, -Inf),
                   test_lower = c(TRUE, FALSE, FALSE),
                   binding = FALSE, h1_spending = TRUE) %>% to_integer()
x %>% text_summary()
#> [1] "Asymmetric two-sided group sequential design with non-binding futility bound, 3 analyses, time-to-event outcome with sample size 506 and 311 events, 90 percent power, 2.5 percent (1-sided) Type I error to detect hazard ratio of 0.9 during the first 3 months and 0.6 thereafter. Enrollment and total study durations are assumed to be 14 and 36.1 months, respectively. Efficacy bounds derived using a Lan-DeMets O'Brien-Fleming approximation spending function (no parameters), tested at tested at IA2, FA. Futility bounds is fixed as -1, -Inf, -Inf, tested at tested at IA1."

# If there are >5 pieces of HRs, we provide a brief summary of HR.
gs_design_ahr(
  fail_rate = define_fail_rate(duration = c(rep(3, 5), Inf),
                               hr = c(0.9, 0.8, 0.7, 0.6, 0.5, 0.4),
                               fail_rate = log(2) / 10, dropout_rate = 0.001),
  info_frac = 1:3/3, test_lower = FALSE) %>%
  text_summary()
#> [1] "One-sided group sequential design with 3 analyses, time-to-event outcome with sample size 290.5 and 218 events, 90 percent power, 2.5 percent (1-sided) Type I error to detect piecewise hazard ratio. Enrollment and total study durations are assumed to be 14 and 36 months, respectively. Efficacy bounds derived using a Lan-DeMets O'Brien-Fleming approximation spending function (no parameters)."