Bland-Altman statistics

The function is computing all relevant Bland-Altman statistics, including bias, lower and upper limits of agreement and their confidence limits.

ba_stat(
  data = stop("data must be specified"),
  var1 = stop("variable must be specified"),
  var2 = stop("variable must be specified"),
  group = NULL,
  alpha = 0.05
)

Arguments

data

A data frame

var1

1st variable to compare (unquoted)

var2

2nd variable to compare (unquoted)

group

grouping variable (unquoted)

alpha

alpha level for the intervals

Value

A tibble with three variables n (number of observations), parameter and value is returned.

See also

ba_plot

Examples

library(tidyr)
tbl <- temperature %>% pivot_wider(names_from = method, values_from = temperature)

# simple example
ba_stat(data = tbl, var1 = infrared, var2 = rectal)
#> # A tibble: 9 × 3
#>       n parameter   value
#>   <int> <chr>       <dbl>
#> 1   450 bias       0.234 
#> 2   450 lloa      -2.85  
#> 3   450 uloa       3.32  
#> 4   450 bias.lcl   0.0879
#> 5   450 lloa.lcl  -3.10  
#> 6   450 uloa.lcl   3.07  
#> 7   450 bias.ucl   0.379 
#> 8   450 lloa.ucl  -2.60  
#> 9   450 uloa.ucl   3.57  

## example with grouping
ba_stat(data = tbl, var1 = infrared, var2 = rectal, group = treatment) %>%
  pivot_wider(names_from = parameter, values_from = value)
#> # A tibble: 6 × 11
#>   treatment     n   bias  lloa  uloa bias.lcl lloa.lcl uloa.lcl bias.ucl lloa.…¹
#>   <fct>     <int>  <dbl> <dbl> <dbl>    <dbl>    <dbl>    <dbl>    <dbl>   <dbl>
#> 1 healthy      75 0.202  -2.51  2.92  -0.116     -3.06     2.37    0.521   -1.96
#> 2 vehicle      75 0.0383 -3.23  3.30  -0.345     -3.88     2.65    0.422   -2.57
#> 3 low dose     75 0.0353 -3.16  3.23  -0.339     -3.80     2.58    0.410   -2.51
#> 4 mid dose     75 0.634  -2.45  3.72   0.273     -3.07     3.09    0.996   -1.83
#> 5 high dose    75 0.173  -3.15  3.50  -0.218     -3.82     2.83    0.563   -2.48
#> 6 SoC          75 0.319  -2.50  3.14  -0.0125    -3.07     2.57    0.650   -1.94
#> # … with 1 more variable: uloa.ucl <dbl>, and abbreviated variable name
#> #   ¹​lloa.ucl