It is often discussed during the planning of a clinical trial whether an interim analysis
is beneficial. The time point of the interim analysis and the end of the clinical trial
are crucial for the decision. Both depend on the recruitment of patients and on the length
of the treatment phase. The package interim allows the instantaneous simulation and
plotting of both the recruitment and treatment phase. Based on these simulations, the
timing of interim analyses can be assessed or different recruitment scenarios
can be compared.
There are three main functions in this package:
The function recruitment generally is the starting point. It simulates screening
and enrollment based on screening characteristics, like e.g. number of available centers
and patients, screen failure rate, etc.
The function treatment simulates the treatment period based on a given recruitment
scenario as simulated by recruitment.
The function trialCourse plots displays of enrollment and treatment simulations.
Two plots are provided; the first one displays center openings and the second one
displays patient screening, enrollment and treatment.
In addition to the main functions, the package comprises a number of auxilliary functions helping to derive or convert parameters required for the three main functions, as well as to derive and plot information on timing of interim analyses. The following auxilliary functions are available: