derive_param_map: Adds a Parameter for Mean Arterial Pressure

In epijim/admiral: ADaM in R Asset Library

Description

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

Usage

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

Arguments

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 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. Permitted Values: list of variables
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
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

(2DIABP + SYSBP) / 3

if it is based on diastolic and systolic blood pressure and

DIABP + 0.01 exp(4.14 - 40.74 / HR) (SYSBP - DIABP)

if it is based on diastolic, systolic blood pressure, and heart rate.

Value

The input dataset with the new parameter added

Author(s)

Stefan Bundfuss

Examples

library(dplyr, warn.conflicts = FALSE)

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

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

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

epijim/admiral documentation built on Feb. 13, 2022, 12:15 a.m.