set_outcome_model function

Specify the outcome model

The time-to-event model for outcome is specified with this method. Any adjustment terms can be specified. For ITT and PP estimands the treatment_var is not specified as it is automatically defined as assigned_treatment. Importantly, the modelling of "time" is specified in this model with arguments for trial start time and follow up time within the trial.

set_outcome_model(object, ...)

## S4 method for signature 'trial_sequence'
set_outcome_model(
  object,
  treatment_var = ~0,
  adjustment_terms = ~1,
  followup_time_terms = ~followup_time + I(followup_time^2),
  trial_period_terms = ~trial_period + I(trial_period^2),
  model_fitter = stats_glm_logit(save_path = NA)
)

## S4 method for signature 'trial_sequence_ITT'
set_outcome_model(
  object,
  adjustment_terms = ~1,
  followup_time_terms = ~followup_time + I(followup_time^2),
  trial_period_terms = ~trial_period + I(trial_period^2),
  model_fitter = stats_glm_logit(save_path = NA)
)

## S4 method for signature 'trial_sequence_PP'
set_outcome_model(
  object,
  adjustment_terms = ~1,
  followup_time_terms = ~followup_time + I(followup_time^2),
  trial_period_terms = ~trial_period + I(trial_period^2),
  model_fitter = stats_glm_logit(save_path = NA)
)

## S4 method for signature 'trial_sequence_AT'
set_outcome_model(
  object,
  treatment_var = "dose",
  adjustment_terms = ~1,
  followup_time_terms = ~followup_time + I(followup_time^2),
  trial_period_terms = ~trial_period + I(trial_period^2),
  model_fitter = stats_glm_logit(save_path = NA)
)

Arguments

• object: A trial_sequence object
• ...: Parameters used by methods
• treatment_var: The treatment term, only used for "as treated" estimands. PP and ITT are fixed to use "assigned_treatment".
• adjustment_terms: Formula terms for any covariates to adjust the outcome model.
• followup_time_terms: Formula terms for followup_time, the time period relative to the start of the trial.
• trial_period_terms: Formula terms for trial_period, the time period of the start of the trial.
• model_fitter: A te_model_fitter object, e.g. from stats_glm_logit().

Returns

A modified object with the outcome_model slot set

Examples

trial_sequence("ITT") |>
  set_data(data_censored) |>
  set_outcome_model(
    adjustment_terms = ~age_s,
    followup_time_terms = ~ stats::poly(followup_time, degree = 2)
  )