The Co-Detection Matrix

Visualising the uncertainty of toxidromic classification in an era of increasing multisubstance use. Co-detections are common and most individual clinical signs point to multiple substance classes simultaneously. The associations are derived from the ASSIST study; analysing toxicological detections and symptoms from 1,348 presentations to the Queen Elizabeth University Hospital, Glasgow from 2022-2025.

How to read this chart: This heatmap shows the Likelihood Ratio (LR+) of drugs given a specific symptom. Instead of looking for a single dark red square, look across the rows. If a symptom row has many colored squares, it has a high Overlap Count, meaning it is shared by too many drugs to be reliably diagnostic on its own.

Low / Unrelated (LR ≤ 1) Stronger Match (LR ≥ 5)