Merge Summary Variables

Merge a summary variable from a dataset to the input dataset.

Usage

derive_var_merged_summary(
  dataset,
  dataset_add,
  by_vars,
  new_vars = NULL,
  new_var,
  filter_add = NULL,
  missing_values = NULL,
  analysis_var,
  summary_fun
)

Arguments

dataset

Input dataset

The variables specified by the by_vars argument are expected to be in the dataset.

dataset_add

Additional dataset

The variables specified by the by_vars and the variables used on the left hand sides of the new_vars arguments are expected.

by_vars

Grouping variables

The expressions on the left hand sides of new_vars are evaluated by the specified variables. Then the resulting values are merged to the input dataset (dataset) by the specified variables.

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

new_vars

New variables to add

The specified variables are added to the input dataset.

A named list of expressions is expected:

LHS refer to a variable.
RHS refers to the values to set to the variable. This can be a string, a symbol, a numeric value, an expression or NA. If summary functions are used, the values are summarized by the variables specified for by_vars.

For example:

  new_vars = exprs(
    DOSESUM = sum(AVAL),
    DOSEMEAN = mean(AVAL)
  )

new_var

Variable to add

Please use new_vars instead.

The specified variable is added to the input dataset (dataset) and set to the summarized values.

filter_add

Filter for additional dataset (dataset_add)

Only observations fulfilling the specified condition are taken into account for summarizing. If the argument is not specified, all observations are considered.

Permitted Values: a condition

missing_values

Values for non-matching observations

For observations of the input dataset (dataset) which do not have a matching observation in the additional dataset (dataset_add) the values of the specified variables are set to the specified value. Only variables specified for new_vars can be specified for missing_values.

Permitted Values: named list of expressions, e.g., exprs(BASEC = "MISSING", BASE = -1)

analysis_var

Analysis variable

Please use new_vars instead.

The values of the specified variable are summarized by the function specified for summary_fun.

summary_fun

Summary function

Please use new_vars instead.

The specified function that takes as input analysis_var and performs the calculation. This can include built-in functions as well as user defined functions, for example mean or function(x) mean(x, na.rm = TRUE).

Value

The output dataset contains all observations and variables of the input dataset and additionally the variables specified for new_vars.

Details

The records from the additional dataset (dataset_add) are restricted to those matching the filter_add condition.
The new variables (new_vars) are created for each by group (by_vars) in the additional dataset (dataset_add) by calling summarize(). I.e., all observations of a by group are summarized to a single observation.
The new variables are merged to the input dataset. For observations without a matching observation in the additional dataset the new variables are set to NA. Observations in the additional dataset which have no matching observation in the input dataset are ignored.

Examples

library(tibble)

# Add a variable for the mean of AVAL within each visit
adbds <- tribble(
  ~USUBJID,  ~AVISIT,  ~ASEQ, ~AVAL,
  "1",      "WEEK 1",      1,    10,
  "1",      "WEEK 1",      2,    NA,
  "1",      "WEEK 2",      3,    NA,
  "1",      "WEEK 3",      4,    42,
  "1",      "WEEK 4",      5,    12,
  "1",      "WEEK 4",      6,    12,
  "1",      "WEEK 4",      7,    15,
  "2",      "WEEK 1",      1,    21,
  "2",      "WEEK 4",      2,    22
)

derive_var_merged_summary(
  adbds,
  dataset_add = adbds,
  by_vars = exprs(USUBJID, AVISIT),
  new_vars = exprs(
    MEANVIS = mean(AVAL, na.rm = TRUE),
    MAXVIS = max(AVAL, na.rm = TRUE)
  )
)
#> Warning: There was 1 warning in `summarise()`.
#> ℹ In argument: `MAXVIS = max(AVAL, na.rm = TRUE)`.
#> ℹ In group 2: `USUBJID = "1"` and `AVISIT = "WEEK 2"`.
#> Caused by warning in `max()`:
#> ! no non-missing arguments to max; returning -Inf
#> # A tibble: 9 × 6
#>   USUBJID AVISIT  ASEQ  AVAL MEANVIS MAXVIS
#>   <chr>   <chr>  <dbl> <dbl>   <dbl>  <dbl>
#> 1 1       WEEK 1     1    10      10     10
#> 2 1       WEEK 1     2    NA      10     10
#> 3 1       WEEK 2     3    NA     NaN   -Inf
#> 4 1       WEEK 3     4    42      42     42
#> 5 1       WEEK 4     5    12      13     15
#> 6 1       WEEK 4     6    12      13     15
#> 7 1       WEEK 4     7    15      13     15
#> 8 2       WEEK 1     1    21      21     21
#> 9 2       WEEK 4     2    22      22     22

# Add a variable listing the lesion ids at baseline
adsl <- tribble(
  ~USUBJID,
  "1",
  "2",
  "3"
)

adtr <- tribble(
  ~USUBJID,     ~AVISIT, ~LESIONID,
  "1",       "BASELINE",  "INV-T1",
  "1",       "BASELINE",  "INV-T2",
  "1",       "BASELINE",  "INV-T3",
  "1",       "BASELINE",  "INV-T4",
  "1",         "WEEK 1",  "INV-T1",
  "1",         "WEEK 1",  "INV-T2",
  "1",         "WEEK 1",  "INV-T4",
  "2",       "BASELINE",  "INV-T1",
  "2",       "BASELINE",  "INV-T2",
  "2",       "BASELINE",  "INV-T3",
  "2",         "WEEK 1",  "INV-T1",
  "2",         "WEEK 1",  "INV-N1"
)

derive_var_merged_summary(
  adsl,
  dataset_add = adtr,
  by_vars = exprs(USUBJID),
  filter_add = AVISIT == "BASELINE",
  new_vars = exprs(LESIONSBL = paste(LESIONID, collapse = ", "))
)
#> # A tibble: 3 × 2
#>   USUBJID LESIONSBL                     
#>   <chr>   <chr>                         
#> 1 1       INV-T1, INV-T2, INV-T3, INV-T4
#> 2 2       INV-T1, INV-T2, INV-T3        
#> 3 3       NA

Usage

Arguments

Value

Details

See also

Examples