Look up normative values for a biomarker

Compares an observed marker to seeded published normative reference values (read from inst/extdata/normative/*.csv), returning a z-score and percentile. This is a scaffold seeded with a few quantitative-EEG markers (delta-alpha ratio, brain symmetry index); extend the CSVs to add markers. When the marker, age band, or montage is unknown the z-score and percentile are returned as NA without raising an error.

Usage

normativeLookup(marker, age = NULL, montage = NULL)

Arguments

marker

A PhysioBiomarker (its name and value are used), or a character marker name (then only reference values are returned, with the z-score/percentile NA).

age

Optional numeric age in years used to select an age-stratified reference row.

montage

Optional character montage used to select a montage-specific reference row.

Value

A named list: marker, value, mean, sd, unit, source, z_score, percentile, and matched (logical). Unknown lookups return NA fields with matched = FALSE.

See also

physioBiomarker(), NormativeReference(), zScore()

Examples

bm <- physioBiomarker(2.35, "DAR")
normativeLookup(bm, age = 40)
#> $marker
#> [1] "DAR"
#> 
#> $value
#> [1] 2.35
#> 
#> $mean
#> [1] 0.8
#> 
#> $sd
#> [1] 0.3
#> 
#> $unit
#> [1] "ratio"
#> 
#> $source
#> [1] "Finnigan 2016 (scaffold seed)"
#> 
#> $z_score
#> [1] 5.166667
#> 
#> $percentile
#> [1] 99.99999
#> 
#> $matched
#> [1] TRUE
#> 
normativeLookup("UNKNOWN_MARKER")   # returns NA fields, no error
#> $marker
#> [1] "UNKNOWN_MARKER"
#> 
#> $value
#> [1] NA
#> 
#> $mean
#> [1] NA
#> 
#> $sd
#> [1] NA
#> 
#> $unit
#> [1] NA
#> 
#> $source
#> [1] NA
#> 
#> $z_score
#> [1] NA
#> 
#> $percentile
#> [1] NA
#> 
#> $matched
#> [1] FALSE
#>