Stepwise covariate modelling for logistic regression

Usage

lr_scm_forward(mod, candidates, threshold = 0.01, seed = NULL)

lr_scm_backward(mod, candidates, threshold = 0.001, seed = NULL)

lr_scm_history(mod)

Arguments

mod: An erlr model object
candidates: Character vector with list of candidate terms
threshold: Threshold to test against
seed: Optional seed to control order of term tests

Value

For lr_scm_forward() and lr_scm_backward(), the updated erlr model is returned, with the SCM history log updated internally. For lr_scm_history(), a data frame is returned containing the SCM history log

Examples

mod0 <- lr_model(ae1 ~ aucss, lr_data)
mod1 <- lr_scm_forward(mod0, candidates = c("sex", "dose"))
#> Using seed = 2475
lr_scm_history(mod1)
#> # A tibble: 3 × 11
#>   iteration attempt step       action term_tested model_tested   model_converged
#>       <int>   <int> <chr>      <chr>  <chr>       <chr>          <lgl>          
#> 1         0       0 base model NA     NA          ae1 ~ aucss    TRUE           
#> 2         1       1 forward    add    ~dose       ae1 ~ aucss +… TRUE           
#> 3         1       2 forward    add    ~sex        ae1 ~ aucss +… TRUE           
#> # ℹ 4 more variables: term_p_value <dbl>, model_aic <dbl>, model_bic <dbl>,
#> #   model_updated <int>

mod2 <- lr_model(ae1 ~ aucss + sex + dose, lr_data)
mod3 <- lr_scm_backward(mod2, candidates = c("sex", "dose"))
#> Using seed = 9165
lr_scm_history(mod3)
#> # A tibble: 4 × 11
#>   iteration attempt step       action term_tested model_tested   model_converged
#>       <int>   <int> <chr>      <chr>  <chr>       <chr>          <lgl>          
#> 1         0       0 base model NA     NA          ae1 ~ aucss +… TRUE           
#> 2         1       1 backward   remove ~sex        ae1 ~ aucss +… TRUE           
#> 3         1       2 backward   remove ~dose       ae1 ~ aucss +… TRUE           
#> 4         2       3 backward   remove ~sex        ae1 ~ aucss    TRUE           
#> # ℹ 4 more variables: term_p_value <dbl>, model_aic <dbl>, model_bic <dbl>,
#> #   model_updated <int>