A244 THE FECAL IMMUNOCHEMICAL TEST (FIT): SELECTED ASPECTS REGARDING ITS EFFECTIVENESS FOR COLORECTAL CANCER SCREENING IN QUEBEC CITY.
Notice bibliographique
Résumé
The FIT has been used in Quebec since September 2013 in replacement for guaiac fecal occult blood test (gFOBT) as part of the province’s colorectal cancer (CRC) screening program (PQDCCR). Its value has already been ascertained elsewhere in Canada and worldwide. For instance, one Canadian study including the data from five provinces obtained a positive predictive value (PPV) of 4.3% for the detection of CRC in average-risk patients. The performance of the FIT needs to be assessed in our province, especially as we use a higher positivity threshold value than in most screening programs. Moreover, there seems to remain a gap between formal indications for a FIT and its actual use in clinical practice. Thus, this research aims to evaluate some aspects related to the effectiveness of the FIT in our setting and its application by prescribers. The primary aim of the study was to determine the PPV for the detection of CRC, advanced adenomas (AA), and significant colorectal lesions (SCL, i.e. CRC and AA combined). The secondary aims of the study were to (i) examine the influence of specific variables on the test’s PPV, such as age, sex, presence of alarm features, and adequacy of the prescription of a FIT, and (ii) identify the FITs that were unjustified, i.e. that were requested for other than asymptomatic, average CRC risk patients. Using the software Endoworks® (Olympus®), in which all colonoscopy reports are saved, we identified retrospectively all colonoscopies conducted for a positive FIT in 2014 at two reference centers of the PQDCCR in Quebec City. We then reviewed manually every corresponding medical record to complete data collection. 559 colonoscopies were reviewed. We obtained PPVs of 6.8% and 46.9% for the detection of CRC and AA, respectively. The PPV for the detection of SCL was 56.1% among men and 45.0% among women (OR 1.56, 95% CI 1.11 – 2.20), whereas it was 59.5% among justified FITs and 43.9% among unwarranted ones (OR 1.88, 95% CI 1.34 – 2.63). Results for AA detection were similar to those of SCL. The PPV for the detection of CRC was 25.0% in the presence of an unexplained iron deficiency anemia and 6.5% when anemia was absent (p=0.0058). In 49.9% of cases, the prescription of a FIT was inappropriate, most often due to macroscopic rectal bleeding. The PPV of the FIT for detecting CRC is higher in our setting than in the rest of Canada, but the clinical significance of this difference is unclear. The test holds a better PPV for detecting SCL and AA among men, and when it is indicated according to PQDCCR recommendations. Unexplained iron deficiency anemia is associated with a higher rate of CRC detection. Half of the positive FITs were not indicated initially. Therefore, physicians should be made more aware of the appropriate use of the FIT. None
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 machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,002 | 0,012 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,002 | 0,002 |
| Études des sciences et des technologies | 0,001 | 0,000 |
| Communication savante | 0,001 | 0,000 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,007 | 0,001 |
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 source (Gemma direct ou Codex distillé), 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 ».