derive_param_bsa: Adds a Parameter for BSA (Body Surface Area) Using the...
In epijim/admiral: ADaM in R Asset Library

Description Usage Arguments Value Author(s) Examples

Adds a record for BSA (Body Surface Area) using the specified derivation method for each by group (e.g., subject and visit) where the source parameters are available.

derive_param_bsa(
  dataset,
  by_vars,
  method,
  set_values_to = vars(PARAMCD = "BSA"),
  height_code = "HEIGHT",
  weight_code = "WEIGHT",
  get_unit_expr,
  filter = NULL
)

`dataset`	Input dataset The variables specified by the `by_vars` parameter, `PARAMCD`, and `AVAL` are expected. The variable specified by `by_vars` and `PARAMCD` must be a unique key of the input dataset after restricting it by the filter condition (`filter` parameter) and to the parameters specified by `HEIGHT` and `WEIGHT`.
`by_vars`	Grouping variables For each group defined by `by_vars` an observation is added to the output dataset. Permitted Values: list of variables
`method`	Derivation method to use. Note that `HEIGHT` is expected in cm and `WEIGHT` is expected in kg: Mosteller: `sqrt(height * weight / 3600)` DuBois-DuBois: `0.20247 * (height/100) ^ 0.725 * weight ^ 0.425` Haycock: `0.024265 * height ^ 0.3964 * weight ^ 0.5378` Gehan-George: `0.0235 * height ^ 0.42246 * weight ^ 0.51456` Boyd: `0.0003207 * (height ^ 0.3) * (1000 * weight) ^ (0.7285 - (0.0188 * log10(1000 * weight)))` Fujimoto: `0.008883 * height ^ 0.663 * weight ^ 0.444` Takahira: `0.007241 * height ^ 0.725 * weight ^ 0.425` Permitted Values: character value
`set_values_to`	Variables to be set The specified variables are set to the specified values for the new observations. For example `vars(PARAMCD = "MAP")` defines the parameter code for the new parameter. Permitted Values: List of variable-value pairs
`height_code`	HEIGHT parameter code The observations where `PARAMCD` equals the specified value are considered as the HEIGHT assessments. It is expected that HEIGHT is measured in cm. Permitted Values: character value
`weight_code`	WEIGHT parameter code The observations where `PARAMCD` equals the specified value are considered as the WEIGHT assessments. It is expected that WEIGHT is measured in kg. Permitted Values: character value
`get_unit_expr`	An expression providing the unit of the parameter The result is used to check the units of the input parameters. Permitted Values: A variable of the input dataset or a function call
`filter`	Filter condition The specified condition is applied to the input dataset before deriving the new parameter, i.e., only observations fulfilling the condition are taken into account. Permitted Values: a condition

The input dataset with the new parameter added

Eric Simms

advs <- tibble::tribble(
  ~USUBJID,      ~PARAMCD, ~PARAM,        ~AVAL, ~AVALU, ~VISIT,
  "01-701-1015", "HEIGHT", "Height (cm)", 170,   "cm",   "BASELINE",
  "01-701-1015", "WEIGHT", "Weight (kg)",  75,   "kg",   "BASELINE",
  "01-701-1015", "WEIGHT", "Weight (kg)",  78,   "kg",   "MONTH 1",
  "01-701-1015", "WEIGHT", "Weight (kg)",  80,   "kg",   "MONTH 2",
  "01-701-1028", "HEIGHT", "Height (cm)", 185,   "cm",   "BASELINE",
  "01-701-1028", "WEIGHT", "Weight (kg)",  90,   "kg",   "BASELINE",
  "01-701-1028", "WEIGHT", "Weight (kg)",  88,   "kg",   "MONTH 1",
  "01-701-1028", "WEIGHT", "Weight (kg)",  85,   "kg",   "MONTH 2",
)

derive_param_bsa(
  advs,
  by_vars = vars(USUBJID, VISIT),
  method = "Mosteller",
  get_unit_expr = AVALU
)

derive_param_bsa(
  advs,
  by_vars = vars(USUBJID, VISIT),
  method = "Fujimoto",
  get_unit_expr = extract_unit(PARAM)
)