Calculate z-scores for MUAC-for-age (MFAZ) and identify outliers based on the SMART methodology. When age is not supplied, wrangling will consist only in detecting outliers from the raw MUAC values. The function only works after the age has been wrangled.
Usage
mw_wrangle_muac(
df,
sex,
muac,
age = NULL,
.recode_sex = TRUE,
.recode_muac = TRUE,
.to = c("cm", "mm", "none"),
.decimals = 3
)
Arguments
- df
A data set object of class
data.frame
to wrangle data from.- sex
A
numeric
orcharacter
vector of child's sex. Code values should only be 1 or "m" for males and 2 or "f" for females. Make sure sex values are coded in either of the aforementioned before calling the function. If input codes are different than expected, the function will stop execution and return an error message with the type of mismatch.- muac
A vector of class
numeric
of child's age in months. If the class is different than expected, the function will stop execution and return an error message indicating the type of mismatch.- age
A vector of class
numeric
of child's age in months.- .recode_sex
Logical. Set to
TRUE
if the values forsex
are not coded as 1 (for males) or 2 (for females). Otherwise, set toFALSE
(default).- .recode_muac
Logical. Set to
TRUE
if the values for raw MUAC should be converted to either centimeters or millimeters. Otherwise, set toFALSE
(default)- .to
A choice of the measuring unit to which the MUAC values should be converted; "cm" for centimeters, "mm" for millimeters and "none" to leave as it is.
- .decimals
The number of decimals places the z-scores should have. Default is 3.
Value
A data frame based on df
. New variables named mfaz
and
flag_mfaz
, of child's MFAZ and detected outliers, will be created. When age
is not supplied, only flag_muac
variable is created. This refers to outliers
detected based on the raw MUAC values.
References
Bilukha, O., & Kianian, B. (2023). Considerations for assessment of measurement quality of mid‐upper arm circumference data in anthropometric surveys and mass nutritional screenings conducted in humanitarian and refugee settings. Maternal & Child Nutrition, 19, e13478. https://doi.org/10.1111/mcn.13478
SMART Initiative (2017). Standardized Monitoring and Assessment for Relief and Transition. Manual 2.0. Available at: https://smartmethodology.org.
Examples
## When age is available, wrangle it first before calling the function ----
w <- mw_wrangle_age(
df = anthro.02,
dos = NULL,
dob = NULL,
age = age,
.decimals = 2
)
### Then apply the function to wrangle MUAC data ----
mw_wrangle_muac(
df = w,
sex = sex,
age = age,
muac = muac,
.recode_sex = TRUE,
.recode_muac = TRUE,
.to = "cm",
.decimals = 3
)
#> ================================================================================
#> # A tibble: 2,267 × 15
#> 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 2 6.01 8.2 68 n 15.2 825. 0.349
#> 2 Zambezia Rural 404 2 6.01 7.1 65.1 n 13.9 287. -0.006
#> 3 Zambezia Rural 399 2 6.11 7.6 64.1 n 15.5 130. 0.9
#> 4 Zambezia Urban 430 2 6.14 7.9 65.9 n 14.8 1277. 0.876
#> 5 Zambezia Urban 468 2 6.28 6.6 59.7 n 13.2 792. 1.38
#> 6 Zambezia Urban 517 2 6.34 6 61.8 n 12.9 480. -0.583
#> 7 Zambezia Urban 461 2 6.34 6.5 64.4 n 12.3 977. -0.732
#> 8 Zambezia Rural 382 2 6.41 6.5 63.4 n 12.6 165. -0.349
#> 9 Zambezia Urban 502 2 6.41 7.5 66 n 14.2 1083. -0.006
#> 10 Zambezia Urban 500 2 6.41 6.8 64.1 n 13.5 972. -0.441
#> # ℹ 2,257 more rows
#> # ℹ 4 more variables: flag_wfhz <dbl>, mfaz <dbl>, flag_mfaz <dbl>,
#> # age_days <dbl>
## When age is not available ----
mw_wrangle_muac(
df = anthro.02,
sex = sex,
age = NULL,
muac = muac,
.recode_sex = TRUE,
.recode_muac = TRUE,
.to = "cm",
.decimals = 3
)
#> # A tibble: 2,267 × 15
#> 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 2 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 2 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
#> 7 Zambezia Urban 461 2 6.34 6.5 64.4 n 123 977. -0.732
#> 8 Zambezia Rural 382 2 6.41 6.5 63.4 n 126 165. -0.349
#> 9 Zambezia Urban 502 2 6.41 7.5 66 n 142 1083. -0.006
#> 10 Zambezia Urban 500 2 6.41 6.8 64.1 n 135 972. -0.441
#> # ℹ 2,257 more rows
#> # ℹ 4 more variables: flag_wfhz <dbl>, mfaz <dbl>, flag_mfaz <dbl>,
#> # flag_muac <dbl>