aba (version 0.0.9)

aba_emmeans: Calculated estimated marginal means.

Description

This function estimates the estimated marginal means (also known as least-square means) and, if relevant, the treatment effects for mmrm, lme, and ancova models.

Usage

aba_emmeans(model)

Arguments

model

abaModel. The fitted aba model to run emmeans on.

Value

an abaEmmeans object. This object contains the emmeans, the paired comparisons (i.e., treatment effect), and the sample size at each visit.

Details

This function is based on the emmeans::emmeans function. This function will only be run for the stats which are supported by emmeans.

Examples

# NOT RUN {
# process data: take first 4 visits, only MCI, use CSF abeta as "treatment",
# and create endpoint as change from baseline in cognition at each visit
df <- adnimerge %>%
  dplyr::filter(
    VISCODE %in% c('bl','m06','m12','m24'),
    !is.na(CSF_ABETA_STATUS_bl),
    DX_bl %in% c('MCI')
  ) %>%
  dplyr::mutate(
    TREATMENT = factor(CSF_ABETA_STATUS_bl, levels=c(0,1),
                       labels=c('Placebo','Treatment')),
    ADAS13 = ADAS13 - ADAS13_bl,
    CDRSB = CDRSB - CDRSB_bl,
    MMSE = MMSE - MMSE_bl
  )

# fit mmrm model for different endpoints, adjusted for covariates
model <- df %>% aba_model() %>%
  set_outcomes(CDRSB, ADAS13, MMSE) %>%
  set_covariates(
    AGE, GENDER, EDUCATION
  ) %>%
  set_stats(
    stat_mmrm(id = 'RID', time = 'VISCODE', treatment = 'TREATMENT')
  ) %>%
  aba_fit()

# run emmeans
# }
# NOT RUN {
model_emmeans <- model %>% aba_emmeans()
# }