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Adds a Parameter for Mean Arterial Pressure

Source: R/derive_param_map.R
derive_param_map.Rd

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
)

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.

Default value

none

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)

Default value

none

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

Default value

exprs(PARAMCD = "MAP")

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

Default value

"SYSBP"

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

Default value

"DIABP"

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

Default value

NULL

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

An expression which is evaluable in the input dataset and results in a character value

Default value

none

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.

Comparing derived numeric variables to fixed values, e.g., PCHG <= -90, may give unexpected results due to floating point representation. For details and solutions see the "Floating Point Comparisons" section in vignette("concepts_conventions").

Permitted values

an unquoted condition, e.g., AVISIT == "BASELINE"

Default value

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.

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_basetype_records(), 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")
#> # A tibble: 12 × 5
#>    USUBJID     PARAMCD PARAM                            AVAL VISIT   
#>    <chr>       <chr>   <chr>                           <dbl> <chr>   
#>  1 01-701-1015 DIABP   Diastolic Blood Pressure (mmHg)  51   BASELINE
#>  2 01-701-1015 DIABP   Diastolic Blood Pressure (mmHg)  50   WEEK 2  
#>  3 01-701-1015 SYSBP   Systolic Blood Pressure (mmHg)  121   BASELINE
#>  4 01-701-1015 SYSBP   Systolic Blood Pressure (mmHg)  121   WEEK 2  
#>  5 01-701-1028 DIABP   Diastolic Blood Pressure (mmHg)  79   BASELINE
#>  6 01-701-1028 DIABP   Diastolic Blood Pressure (mmHg)  80   WEEK 2  
#>  7 01-701-1028 SYSBP   Systolic Blood Pressure (mmHg)  130   BASELINE
#>  8 01-701-1028 SYSBP   Systolic Blood Pressure (mmHg)  132   WEEK 2  
#>  9 01-701-1015 MAP     Mean Arterial Pressure (mmHg)    74.3 BASELINE
#> 10 01-701-1015 MAP     Mean Arterial Pressure (mmHg)    73.7 WEEK 2  
#> 11 01-701-1028 MAP     Mean Arterial Pressure (mmHg)    96   BASELINE
#> 12 01-701-1028 MAP     Mean Arterial Pressure (mmHg)    97.3 WEEK 2  

# 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)
)
#> # A tibble: 16 × 5
#>    USUBJID     PARAMCD PARAM                            AVAL VISIT   
#>    <chr>       <chr>   <chr>                           <dbl> <chr>   
#>  1 01-701-1015 PULSE   Pulse (beats/min)                59   BASELINE
#>  2 01-701-1015 PULSE   Pulse (beats/min)                61   WEEK 2  
#>  3 01-701-1015 DIABP   Diastolic Blood Pressure (mmHg)  51   BASELINE
#>  4 01-701-1015 DIABP   Diastolic Blood Pressure (mmHg)  50   WEEK 2  
#>  5 01-701-1015 SYSBP   Systolic Blood Pressure (mmHg)  121   BASELINE
#>  6 01-701-1015 SYSBP   Systolic Blood Pressure (mmHg)  121   WEEK 2  
#>  7 01-701-1028 PULSE   Pulse (beats/min)                62   BASELINE
#>  8 01-701-1028 PULSE   Pulse (beats/min)                77   WEEK 2  
#>  9 01-701-1028 DIABP   Diastolic Blood Pressure (mmHg)  79   BASELINE
#> 10 01-701-1028 DIABP   Diastolic Blood Pressure (mmHg)  80   WEEK 2  
#> 11 01-701-1028 SYSBP   Systolic Blood Pressure (mmHg)  130   BASELINE
#> 12 01-701-1028 SYSBP   Systolic Blood Pressure (mmHg)  132   WEEK 2  
#> 13 01-701-1015 MAP     Mean Arterial Pressure (mmHg)    73.0 BASELINE
#> 14 01-701-1015 MAP     Mean Arterial Pressure (mmHg)    72.9 WEEK 2  
#> 15 01-701-1028 MAP     Mean Arterial Pressure (mmHg)    95.6 BASELINE
#> 16 01-701-1028 MAP     Mean Arterial Pressure (mmHg)    99.2 WEEK 2