Triggering Condition by Number of Events or Non-missing Observations of an Endpoint

Define a condition to trigger trial milestone by the number of events of a time-to-event endpoint or the number of non-missing observations of a non-time-to-event endpoint. The milestone will be triggered when a trial has observed at least the specified number of endpoint events (or non-missing observations). It can be used combined with conditions specified by calendarTime and enrollment.

Number of events for a time-to-event endpoint can vary at different milestones as more patients are randomized into a trial, or more events onset over time.

Number of non-missing observations for a non-time-to-event endpoint can vary at different milestones as more patients are randomized into a trial, or more patients have been treated until their readout time (thus, NA turns to a value).

Both numbers are affected by dropout.

Refer to the vignette to learn how to define milestones when performing simulation using TrialSimulator.

Usage

eventNumber(endpoint, n, ..., arms = NULL)

Arguments

endpoint: character. Name of an endpoint. It should be something that is specified in the argument name in endpoint().
n: integer. Targeted number of events or non-missing obervations, depending on the type of endpoint.
...: subset conditions compatible with dplyr::filter. Number of events/observations will be counted on subset of trial data only.
arms: vector of character. Name of arms on which the number of events/observations is counted. If NULL, use all arms that are not yet removed from the trial (using remove_arms()) by the time of calculation. Otherwise, every name must be an arm that has ever been added to the trial by the time of calculation; an unknown name is an error. An arm that has been removed by then is counted as specified, with a warning unless the trial is silent, so that a count including arms dropped at an earlier milestone is deliberate.

Value

an object of class `Condition`