R/find_esgrid.R

In OVtool: Omitted Variable Tool

#### setup es grid ####
find_esgrid = function(my_data, my_cov, treatment, outcome, my_estimand){
  # y-axis of plot (correlation between covariates and outcome)
  obs_cors = rep(NA, ncol(data.frame(my_data[,my_cov])))
  for(i in 1:length(obs_cors)){
    if(is.factor(my_data[,my_cov[i]])){
      obs_cors[i] = abs(stats::cor(as.numeric(my_data[,my_cov[i]]),
                            my_data[,outcome],"pairwise.complete.obs"))
    } else {
      obs_cors[i] = abs(stats::cor(as.numeric(as.character(my_data[,my_cov[i]])),
                            my_data[,outcome],"pairwise.complete.obs"))
    }
  }

  # x-axis of plot (effect size)
  mean_noNA = function(x){return(mean(x, na.rm=T))}
  sd_noNA = function(x){return(stats::sd(x, na.rm=T))}
  mean_sd_bygroup = my_data %>%
    dplyr::select(.data[[treatment]], my_cov) %>%
    dplyr::mutate_if(is.factor, as.numeric) %>%
    dplyr::group_by(.data[[treatment]]) %>%
    # adding in so if there are factors, we should make numeric.
    dplyr::summarize_all(list(mean_noNA, sd_noNA)) %>%
    data.frame()

  es_cov = rep(NA, length(my_cov))

  if(my_estimand == "ATE"){
    if(length(my_cov) > 1){
      for(i in 1:length(my_cov)){
        # denominator for ATE
        diff_means = diff(mean_sd_bygroup[,colnames(mean_sd_bygroup)[grep(paste0("^", my_cov[i], "_fn1$"), colnames(mean_sd_bygroup))]])
        denom_ATE = sqrt(sum(mean_sd_bygroup[,colnames(mean_sd_bygroup)[grep(paste0("^", my_cov[i], "_fn2$"), colnames(mean_sd_bygroup))]]^2)/2)
        es_cov[i] = abs(diff_means/denom_ATE)
      }
    } else{
      diff_means = diff(mean_sd_bygroup$fn1)
      denom_ATE = sqrt(sum(mean_sd_bygroup$fn2^2)/2)
      es_cov[i] = abs(diff_means/denom_ATE)
    }

  } else if(my_estimand == "ATT"){
    if(length(my_cov) > 1){
      for(i in 1:length(my_cov)){
        diff_means = diff(mean_sd_bygroup[,colnames(mean_sd_bygroup)[grep(paste0("^", my_cov[i], "_fn1$"), colnames(mean_sd_bygroup))]])
        treat_only = mean_sd_bygroup %>% dplyr::filter(.data[[treatment]] == 1) %>% data.frame()
        denom_ATT = treat_only[,colnames(treat_only)[grep(paste0("^", my_cov[i], "_fn2$"),
                                                          colnames(treat_only))]]
        es_cov[i] = abs(diff_means/denom_ATT)
      }
    } else{
      diff_means = diff(mean_sd_bygroup$fn1)
      denom_ATT = mean_sd_bygroup$fn2[mean_sd_bygroup[,treatment]==1]
      es_cov[i] = abs(diff_means/denom_ATT)
    }
  }
  obs_cors = cbind(obs_cors, es_cov)
  obs_cors = obs_cors %>%
    data.frame() %>%
    dplyr::mutate(cov=my_cov)

  colnames(obs_cors) = c("Cor_Outcome", "ES", "cov")

  return(obs_cors)
}