add Calvert equation for carboplatin

NAMESPACE

@@ -12,6 +12,7 @@ export(calc_amts_for_conc)
 export(calc_baseline_scr)
 export(calc_bmi)
 export(calc_bsa)
+export(calc_carboplatin_calvert)
 export(calc_creat)
 export(calc_creat_neo)
 export(calc_dosing_weight)

R/calc_carboplatin_calvert.R

@@ -0,0 +1,25 @@
+#' Calvert equation for carboplatin
+#' 
+#' The Calvert equation calculates a dose expected to bring the patient to the
+#' target AUC given their glomerular filtration rate (GFR). The original 
+#' equation was developed on a data set of 18 individuals with GFR of 
+#' 33-136 ml/min.
+#' 
+#' @references \href{https://ascopubs.org/doi/abs/10.1200/JCO.1989.7.11.1748}{
+#' Calvert et al., Journal of Clinical Oncology (1976)}
+#' 
+#' @param target_auc target AUC, in mg/ml-min, typically between 2-8 mg/ml-min
+#' @param gfr glomerular filtration rate, in ml/min. See also 
+#'   `clinPK::calc_egfr`.
+#' @param ... arguments passed on to `calc_egfr` if gfr is not supplied
+#' @examples
+#' calc_carboplatin_calvert(5, 100)
+#' calc_carboplatin_calvert(4, 30)
+#' calc_carboplatin_calvert(2, sex = "male", age = 50, scr = 1.1, weight = 70)
+#' 
+#' @export
+
+calc_carboplatin_calvert <- function(target_auc, gfr = NULL, ...) {
+  if (is.null(gfr)) gfr <- calc_egfr(..., relative=FALSE)[["value"]]
+  target_auc * (1.2 * gfr + 20)
+}

tests/testthat/test_calc_carboplatin_calvert.R

@@ -0,0 +1,37 @@
+test_that("calvert eqn with egfr supplied", {
+  expect_equal(calc_carboplatin_calvert(5, 100), 700)
+  expect_equal(calc_carboplatin_calvert(4, 30), 224)
+})
+
+test_that("calvert eqn with egfr supplied", {
+  expect_equal(
+    calc_carboplatin_calvert(
+      5, 
+      sex = "male", 
+      age = 50, 
+      scr = 1.1, 
+      weight = 70,
+      verbose = FALSE
+    ), 
+    577.27273
+  )
+})
+
+test_that("calvert eqn uses absolute egfr", {
+  expect_equal(
+    round(
+      calc_carboplatin_calvert(
+        5, 
+        sex = "male", 
+        age = 5, 
+        scr = 1.1, 
+        weight = 15,
+        height = 90,
+        method = "schwartz_revised",
+        verbose = FALSE
+      ),
+      2
+    ), 
+    169.49
+  )
+})