calculate_probabilities: Calculate dose-path probabilities

In escalation: Modular Approach to Dose Finding Clinical Trials

Calculate dose-path probabilities

Description

Crystallise a set of dose_paths with probabilities to calculate how likely each path is. Once probabilised in this way, the probabilities of the terminal nodes in this set of paths will sum to 1. This allows users to calculate operating characteristics.

Usage

calculate_probabilities(dose_paths, true_prob_tox, true_prob_eff = NULL, ...)

Arguments

dose_paths	Object of type dose_paths
true_prob_tox	Numeric vector, true probability of toxicity.
true_prob_eff	vector of true efficacy probabilities, optionally NULL if efficacy not analysed.
...	Extra parameters

See Also

dose_paths

Examples

# Phase 1 example.
# Calculate dose paths for the first three cohorts in a 3+3 trial of 5 doses:
paths <- get_three_plus_three(num_doses = 5) %>%
  get_dose_paths(cohort_sizes = c(3, 3, 3))

# Set the true probabilities of toxicity
true_prob_tox <- c(0.12, 0.27, 0.44, 0.53, 0.57)
# And calculate exact operating performance
x <- paths %>% calculate_probabilities(true_prob_tox)
prob_recommend(x)

# Phase 1/2 example.
prob_select = c(0.1, 0.3, 0.5, 0.07, 0.03)
selector_factory <- get_random_selector(prob_select = prob_select,
                                        supports_efficacy = TRUE)
paths <- selector_factory %>% get_dose_paths(cohort_sizes = c(2, 2))
true_prob_eff <- c(0.27, 0.35, 0.41, 0.44, 0.45)
x <- paths %>% calculate_probabilities(true_prob_tox = true_prob_tox,
                                       true_prob_eff = true_prob_eff)
prob_recommend(x)

escalation documentation built on May 31, 2023, 6:32 p.m.