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Define wasting

Source: R/prev_define_wasting.R
define_wasting.Rd

Define if a given observation in the data set is wasted or not, and its respective form of wasting (global, severe or moderate) on the basis of z-scores of weight-for-height (WFHZ), muac-for-age (MFAZ), raw MUAC values and combined case-definition.

Usage

define_wasting(
  df,
  zscores = NULL,
  muac = NULL,
  edema = NULL,
  .by = c("zscores", "muac", "combined")
)

Arguments

df

A data set object of class data.frame to use. It must have been wrangled using this package's wrangling functions for WFHZ or MUAC, or both (for combined) as appropriate.

zscores

A vector of class double of WFHZ or MFAZ values. If the class does not match the expected type, the function will stop execution and return an error message indicating the type of mismatch.

muac

A vector of class integer or numeric of raw MUAC values in millimeters. If the class does not match the expected type, the function will stop execution and return an error message indicating the type of mismatch.

edema

A vector of class character of edema. Default is NULL. If the class does not match the expected type, the function will stop execution and return an error message indicating the type of mismatch. Code values should be "y" for presence and "n" for absence of bilateral edema. If different, the function will stop execution and return an error indicating the issue.

.by

A choice of the criterion by which the case-definition should done. Choose zscores for WFHZ or MFAZ, muac for raw MUAC and combined for combined.

Value

Three vectors named gam, sam and mam, of class numeric, same length as inputs, containing dummy values: 1 for case and 0 for not case. This is added to df. When combined is selected, vector's names become cgam, csam and cmam.

Examples

## Case-definition by z-scores ----
z <- anthro.02 |>
  define_wasting(
    zscores = wfhz,
    muac = NULL,
    edema = edema,
    .by = "zscores"
  )
head(z)
#> # A tibble: 6 × 17
#>   province strata cluster   sex   age weight height edema  muac wtfactor   wfhz
#>   <chr>    <chr>    <int> <dbl> <dbl>  <dbl>  <dbl> <chr> <dbl>    <dbl>  <dbl>
#> 1 Zambezia Rural      391     1  6.01    8.2   68   n       152     825.  0.349
#> 2 Zambezia Rural      404     2  6.01    7.1   65.1 n       139     287. -0.006
#> 3 Zambezia Rural      399     1  6.11    7.6   64.1 n       155     130.  0.9  
#> 4 Zambezia Urban      430     2  6.14    7.9   65.9 n       148    1277.  0.876
#> 5 Zambezia Urban      468     2  6.28    6.6   59.7 n       132     792.  1.38 
#> 6 Zambezia Urban      517     2  6.34    6     61.8 n       129     480. -0.583
#> # ℹ 6 more variables: flag_wfhz <dbl>, mfaz <dbl>, flag_mfaz <dbl>, gam <dbl>,
#> #   sam <dbl>, mam <dbl>

## Case-definition by MUAC ----
m <- anthro.02 |>
  define_wasting(
    zscores = NULL,
    muac = muac,
    edema = edema,
    .by = "muac"
  )
head(m)
#> # A tibble: 6 × 17
#>   province strata cluster   sex   age weight height edema  muac wtfactor   wfhz
#>   <chr>    <chr>    <int> <dbl> <dbl>  <dbl>  <dbl> <chr> <dbl>    <dbl>  <dbl>
#> 1 Zambezia Rural      391     1  6.01    8.2   68   n       152     825.  0.349
#> 2 Zambezia Rural      404     2  6.01    7.1   65.1 n       139     287. -0.006
#> 3 Zambezia Rural      399     1  6.11    7.6   64.1 n       155     130.  0.9  
#> 4 Zambezia Urban      430     2  6.14    7.9   65.9 n       148    1277.  0.876
#> 5 Zambezia Urban      468     2  6.28    6.6   59.7 n       132     792.  1.38 
#> 6 Zambezia Urban      517     2  6.34    6     61.8 n       129     480. -0.583
#> # ℹ 6 more variables: flag_wfhz <dbl>, mfaz <dbl>, flag_mfaz <dbl>, gam <dbl>,
#> #   sam <dbl>, mam <dbl>

## Case-definition by combined ----
c <- anthro.02 |>
  define_wasting(
    zscores = wfhz,
    muac = muac,
    edema = edema,
    .by = "combined"
  )
head(c)
#> # A tibble: 6 × 17
#>   province strata cluster   sex   age weight height edema  muac wtfactor   wfhz
#>   <chr>    <chr>    <int> <dbl> <dbl>  <dbl>  <dbl> <chr> <dbl>    <dbl>  <dbl>
#> 1 Zambezia Rural      391     1  6.01    8.2   68   n       152     825.  0.349
#> 2 Zambezia Rural      404     2  6.01    7.1   65.1 n       139     287. -0.006
#> 3 Zambezia Rural      399     1  6.11    7.6   64.1 n       155     130.  0.9  
#> 4 Zambezia Urban      430     2  6.14    7.9   65.9 n       148    1277.  0.876
#> 5 Zambezia Urban      468     2  6.28    6.6   59.7 n       132     792.  1.38 
#> 6 Zambezia Urban      517     2  6.34    6     61.8 n       129     480. -0.583
#> # ℹ 6 more variables: flag_wfhz <dbl>, mfaz <dbl>, flag_mfaz <dbl>, cgam <dbl>,
#> #   csam <dbl>, cmam <dbl>