Likelihood ratio for antemortem ingestion versus postmortem artefact

Quantifies support for an analyte being present antemortem versus arising from a postmortem process (e.g. microbial ethanol production during decomposition or submersion). The caller supplies an observed marker value – typically a specific secondary metabolite that only a living, functioning liver produces (ethyl glucuronide / ethyl sulfate for ethanol), or a congener/matrix ratio – and Gaussian models for the two hypotheses. This is a thin domain wrapper over morie_taphonomy_preservation_lr.

Usage

morie_tox_antemortem_lr(marker, antemortem, postmortem)

Arguments

marker

Observed marker value(s) (e.g. EtG concentration, or a parent:artefact ratio).

antemortem

list(mean =, sd =) for the marker under antemortem ingestion (H1).

postmortem

list(mean =, sd =) for the marker under a postmortem-artefact process (H2).

Value

The list returned by morie_taphonomy_likelihood_ratio (lr, log10_lr, verbal, interpretation, and the two log-likelihoods), with interpretation reframed for the antemortem question.

Examples

# EtG well above the postmortem-artefact background supports antemortem intake
morie_tox_antemortem_lr(
  marker = 1.8,
  antemortem = list(mean = 2.0, sd = 0.5),
  postmortem = list(mean = 0.1, sd = 0.3)
)$verbal
#> [1] "extremely strong support for H1"