R/compute_icers.R

In twig: For Streamlining Decision and Economic Evaluation Models using Grammar of Modeling

compute_icers <- function(non_d) {
  if (nrow(non_d) > 1) {
    non_d[1, "ICER"] <- NA
    for (i in 2:nrow(non_d)) {
      inc_cost <- (non_d[i, "Cost"] - non_d[i - 1, "Cost"])
      inc_effect <- (non_d[i, "Effect"] - non_d[i - 1, "Effect"])
      non_d[i, "Inc_Cost"] <- inc_cost
      non_d[i, "Inc_Effect"] <- inc_effect
      non_d[i, "ICER"] <- inc_cost/inc_effect
    }
  } else {
    non_d[1, c("ICER", "Inc_Cost", "Inc_Effect")] <- NA
  }
  return(non_d)
}