admiral (version 1.1.1)

derive_param_map: Adds a Parameter for Mean Arterial Pressure

Description

Adds a record for mean arterial pressure (MAP) for each by group (e.g., subject and visit) where the source parameters are available.

Note: This is a wrapper function for the more generic derive_param_computed().

Usage

derive_param_map(
  dataset,
  by_vars,
  set_values_to = exprs(PARAMCD = "MAP"),
  sysbp_code = "SYSBP",
  diabp_code = "DIABP",
  hr_code = NULL,
  get_unit_expr,
  filter = NULL
)

Value

The input dataset with the new parameter added. Note, a variable will only be populated in the new parameter rows if it is specified in by_vars.

Arguments

dataset

Input dataset

The variables specified by the by_vars argument are expected to be in the dataset. PARAMCD, and AVAL are expected as well.

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 sysbp_code, diabp_code and hr_code.

by_vars

Grouping variables

For each group defined by by_vars an observation is added to the output dataset. Only variables specified in by_vars will be populated in the newly created records.

Permitted Values: list of variables created by exprs() e.g. exprs(USUBJID, VISIT)

set_values_to

Variables to be set

The specified variables are set to the specified values for the new observations. For example exprs(PARAMCD = "MAP") defines the parameter code for the new parameter.

Permitted Values: List of variable-value pairs

sysbp_code

Systolic blood pressure parameter code

The observations where PARAMCD equals the specified value are considered as the systolic blood pressure assessments.

Permitted Values: character value

diabp_code

Diastolic blood pressure parameter code

The observations where PARAMCD equals the specified value are considered as the diastolic blood pressure assessments.

Permitted Values: character value

hr_code

Heart rate parameter code

The observations where PARAMCD equals the specified value are considered as the heart rate assessments.

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

Details

The analysis value of the new parameter is derived as $$\frac{2DIABP + SYSBP}{3}$$ if it is based on diastolic and systolic blood pressure and $$DIABP + 0.01 e^{4.14 - \frac{40.74}{HR}} (SYSBP - DIABP)$$ if it is based on diastolic, systolic blood pressure, and heart rate.

See Also

compute_map()

BDS-Findings Functions for adding Parameters/Records: default_qtc_paramcd(), derive_expected_records(), derive_extreme_event(), derive_extreme_records(), derive_locf_records(), derive_param_bmi(), derive_param_bsa(), derive_param_computed(), derive_param_doseint(), derive_param_exist_flag(), derive_param_exposure(), derive_param_framingham(), derive_param_qtc(), derive_param_rr(), derive_param_wbc_abs(), derive_summary_records()

Examples

library(tibble)
library(dplyr, warn.conflicts = FALSE)

advs <- tibble::tribble(
  ~USUBJID, ~PARAMCD, ~PARAM, ~AVAL, ~VISIT,
  "01-701-1015", "PULSE", "Pulse (beats/min)", 59, "BASELINE",
  "01-701-1015", "PULSE", "Pulse (beats/min)", 61, "WEEK 2",
  "01-701-1015", "DIABP", "Diastolic Blood Pressure (mmHg)", 51, "BASELINE",
  "01-701-1015", "DIABP", "Diastolic Blood Pressure (mmHg)", 50, "WEEK 2",
  "01-701-1015", "SYSBP", "Systolic Blood Pressure (mmHg)", 121, "BASELINE",
  "01-701-1015", "SYSBP", "Systolic Blood Pressure (mmHg)", 121, "WEEK 2",
  "01-701-1028", "PULSE", "Pulse (beats/min)", 62, "BASELINE",
  "01-701-1028", "PULSE", "Pulse (beats/min)", 77, "WEEK 2",
  "01-701-1028", "DIABP", "Diastolic Blood Pressure (mmHg)", 79, "BASELINE",
  "01-701-1028", "DIABP", "Diastolic Blood Pressure (mmHg)", 80, "WEEK 2",
  "01-701-1028", "SYSBP", "Systolic Blood Pressure (mmHg)", 130, "BASELINE",
  "01-701-1028", "SYSBP", "Systolic Blood Pressure (mmHg)", 132, "WEEK 2"
)

# Derive MAP based on diastolic and systolic blood pressure
advs %>%
  derive_param_map(
    by_vars = exprs(USUBJID, VISIT),
    set_values_to = exprs(
      PARAMCD = "MAP",
      PARAM = "Mean Arterial Pressure (mmHg)"
    ),
    get_unit_expr = extract_unit(PARAM)
  ) %>%
  filter(PARAMCD != "PULSE")

# Derive MAP based on diastolic and systolic blood pressure and heart rate
derive_param_map(
  advs,
  by_vars = exprs(USUBJID, VISIT),
  hr_code = "PULSE",
  set_values_to = exprs(
    PARAMCD = "MAP",
    PARAM = "Mean Arterial Pressure (mmHg)"
  ),
  get_unit_expr = extract_unit(PARAM)
)