B-288 Turning False Positive Screening into True Positive Results
Notice bibliographique
Résumé
Abstract Background After conducting a retrospective analysis of our laboratory data, we identified a notable disparity between immunoassay screen and mass spectrometry confirmation results for benzodiazepines. This prompted an investigation into whether the prevalence of false negative benzodiazepine results stemmed from the inadequacy of the immunoassay or the absence of new psychoactive substances (NPS) in our mass spectrometry confirmation assay. To determine the latter, we added four NPS benzodiazepines and their metabolites to our confirmation panel. Monitoring drug seizure records as well as reports detailing emerging substances were helpful in guiding which NPS to add. The objective of this study was to determine whether the addition of NPS benzodiazepines to our confirmation panel would increase the agreement between screen and confirmation benzodiazepine results in an opioid dependent population. Methods Urine samples that screened positive for benzodiazepines with immunoassay and confirmed negative by mass spectrometry over a 6-month timeframe were selected for analysis. Four NPS were added to our confirmation panel which included bromazolam, flubromazepam, flubromazolam, flualprazolam as well as their metabolites alpha-OH bromazolam, 3-OH flubromazepam, alpha-OH flubromazolam and alpha-OH flualprazolam. Immunoassay data was obtained using an Olympus AU480 instrument, while mass spectrometry results were acquired through an internally developed dynamic multiple reaction monitoring method on an Agilent 6470 triple quadrupole instrument. Results In the analysis of 476 urine samples using a cut-off value of 50 ng/mL, 55.3% of the samples tested positive for bromazolam, 83.0% for alpha-OH bromazolam, 0% for flubromazepam, 41.8% for 3-OH flubromazepam, 0% for flubromazolam, 0.2% for alpha-OH flubromazolam, 1.3% for flualprazolam and 6.7% for alpha-OH flualprazolam. Using a cut-off value of 10 ng/mL which represents the limit of quantitation, 75.4% tested positive for bromazolam, 89.9% for alpha-OH bromazolam, 2.1% for flubromazepam, 60.5% for 3-OH flubromazepam, 0% for flubromazolam, 0.2% for alpha-OH flubromazolam, 3.4% for flualprazolam and 9.7% for alpha-OH flualprazolam. In total, among the 476 samples that initially screened positive but confirmed negative, 95.8% confirmed positive for benzodiazepines with the inclusion of the four NPS benzodiazepines and their metabolites into our confirmation panel. Of the samples that tested positive for NPS benzodiazepines, 77.1% were also positive for fentanyl, and 95.2% were positive for norfentanyl. Conclusions The incorporation of NPS benzodiazepines into our confirmation panel significantly enhanced the concordance between immunoassay screen and mass spectrometry confirmation results. The discrepancies we observed with benzodiazepines were not predominantly linked to immunoassay challenges. Rather, they were due to the presence of NPS benzodiazepines commonly found in benzo-dope preparations, not accounted for in our mass spectrometry confirmation panel. The inclusion of NPS benzodiazepines into our confirmation panel has improved the reporting of useful diagnostic information which can be used to support harm reduction efforts.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,008 | 0,278 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,001 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,001 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,001 | 0,002 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».