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The function j_index produces J-Index values a tibble object.

Usage

j_index(data)

Arguments

data

DataFrame object with column names "id", "time", and "gl", or numeric vector of glucose values.

Value

If a data.frame object is passed, then a tibble object with two columns: subject id and corresponding J-Index value is returned. If a vector of glucose values is passed, then a tibble object with just the J-Index value is returned. as.numeric() can be wrapped around the latter to output just a numeric value.

Details

A tibble object with 1 row for each subject, a column for subject id and a column for J-Index values is returned. NA glucose values are omitted from the calculation of the J-Index.

J-Index score is calculated by \(.001 * [mean(BG) + sd(BG)]^2\) where BG is the list of Blood Glucose Measurements.

References

Wojcicki (1995) "J"-index. A new proposition of the assessment of current glucose control in diabetic patients Hormone and Metabolic Research 27 .41-42, doi:10.1055/s-2007-979906 .

Examples


data(example_data_1_subject)
j_index(example_data_1_subject)
#> # A tibble: 1 × 2
#>   id        J_index
#>   <fct>       <dbl>
#> 1 Subject 1    24.6

data(example_data_5_subject)
j_index(example_data_5_subject)
#> # A tibble: 5 × 2
#>   id        J_index
#>   <fct>       <dbl>
#> 1 Subject 1    24.6
#> 2 Subject 2    73.3
#> 3 Subject 3    39.5
#> 4 Subject 4    25.2
#> 5 Subject 5    54.4