Strategic Decision-Making by a Forensic Toxicology Laboratory in Response to an Emerging NPS: Detection, Quantitation and Interpretation of Carfentanil in Death Investigations in Ontario, Canada, July 2017 to June 2018
Bibliographic record
Abstract
The proliferation of novel psychoactive substances (NPS) and the current opioid epidemic creates challenges for a toxicology laboratory. Methods capable of detecting and quantitating emerging compounds must be established despite limited information on toxicologically relevant concentrations. This paper will (i) describe how a publicly funded forensic laboratory reacted to the emergence of carfentanil as a public safety concern and (ii) contribute to the existing forensic literature by presenting a series of deaths involving carfentanil between July 2017 and June 2018. The Centre of Forensic Sciences is the primary provider of forensic toxicology testing in medicolegal death investigations in the province of Ontario. When carfentanil was first identified in the illicit drug supply, routine screening methods used by this laboratory were not sufficiently sensitive to detect the drug at concentrations expected in blood samples. Previously validated, multi-target liquid chromatography-tandem mass spectrometry (LC-MS-MS) quantitative methods already in use by the laboratory did show improved detectability for carfentanil. Thus, an existing LC-MS-MS method was adapted to include carfentanil, achieving improved sensitivity while also providing quantitation in suspected drug-related deaths. This approach had the added benefit that the LC-MS-MS method selected for modification was used in all death investigations requiring toxicology analysis in Ontario, thereby providing an opportunity for surveillance. Using this method, 4,953 cases were analyzed with carfentanil detected at a concentration greater than the limit of detection (0.05 ng/mL) in 160 decedents. Postmortem blood carfentanil concentrations ranged from less than 0.1 to 9.2 ng/mL. Of the 160 carfentanil-positive cases, 156 were classified as either mixed drug toxicity or carfentanil overdose. The approach described enabled this laboratory to efficiently implement a quantitative test for carfentanil in all death investigations, providing a useful template for modifying existing methods when a new psychoactive substance becomes available in the population.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".