phase1_outcomes_to_cohorts: Break a phase I outcome string into a list of cohort parts.

In escalation: A Modular Approach to Dose-Finding Clinical Trials

Break a phase I outcome string into a list of cohort parts.

Description

Break a phase I outcome string into a list of cohort parts.

Break a phase I outcome string into a list of cohort parts.

The outcome string describes the doses given, outcomes observed and the timing of analyses that recommend a dose. The format of the string is described in Brock (2019), and that itself is the phase I analogue of the similar idea described in Brock _et al_. (2017).

The letters T and N are used to represents patients that experienced (T)oxicity and (N)o toxicity. These letters are concatenated after numerical dose-levels to convey the outcomes of cohorts of patients. For instance, 2NNT represents a cohort of three patients that were treated at dose-level 2, one of whom experienced toxicity, and two that did not. The results of cohorts are separated by spaces and it is assumed that a dose-finding decision takes place at the end of a cohort. Thus, 2NNT 1NN builds on our previous example, where the next cohort of two were treated at dose-level 1 and neither of these patients experienced toxicity. See examples.

Usage

phase1_outcomes_to_cohorts(outcomes)

Arguments

outcomes

character string representing the doses given, outcomes observed, and timing of analyses. See Description.

Value

a list with a slot for each cohort. Each cohort slot is itself a list, containing elements: * dose, the integer dose delivered to the cohort; * outcomes, a character string representing the T or N outcomes for the patients in this cohort.

References

Brock, K. (2019). trialr: Bayesian Clinical Trial Designs in R and Stan. arXiv:1907.00161 [stat.CO]

Brock, K., Billingham, L., Copland, M., Siddique, S., Sirovica, M., & Yap, C. (2017). Implementing the EffTox dose-finding design in the Matchpoint trial. BMC Medical Research Methodology, 17(1), 112. https://doi.org/10.1186/s12874-017-0381-x

Examples

x = phase1_outcomes_to_cohorts('1NNN 2NNT 3TT')
length(x)
x[[1]]$dose
x[[1]]$outcomes
x[[2]]$dose
x[[2]]$outcomes
x[[3]]$dose
x[[3]]$outcomes

escalation documentation built on June 27, 2024, 5:09 p.m.