Re: "The Influence of Health and Lifestyle Characteristics on the Relation of Serum 25-Hydroxyvitamin D With Risk of Colorectal and Breast Cancer in Postmenopausal Women"
Notice bibliographique
Résumé
A recent paper (1) found that the serum 25-hydroxyvitamin D (25(OH)D) concentration at the time of enrollment in the Women's Health Initiative was inversely correlated with invasive colorectal cancer for all models but only for the unadjusted models for breast cancer. Overlooked in the paper was any discussion of the role of follow-up time on the results. Another recent paper (2) showed that, for follow-up times longer than 3 years, no nested case-control study had found an inverse correlation between the prediagnostic serum 25(OH)D concentration and incidence of breast cancer. The regression fit to the data for relative risk went from 0.6 at 0 years for case-control studies to 0.95 at 7 years. However, for colorectal cancer, significant inverse correlations were found for follow-up times out to 12 years, although the regression fit went from relative risk = 0.4 at 5 years to 0.7 at 14 years. The changes in relative risk were 0.05/year for breast cancer and 0.033/year for colorectal cancer. Thus, the fact that the vitamin D effect is stronger for colorectal cancer than for breast cancer seems to be why it is easier to find a significant effect for longer follow-up periods. There is additional evidence that long follow-up times with a single serum 25(OH)D concentration value from the time of enrollment are problematic. A study in Finland found a significant inverse correlation for non-Hodgkin's lymphoma for follow-up times less than 7 years but an insignificant direct correlation for later diagnosis (3). A study in Norway found a regression coefficient of 0.4 for serum 25(OH)D concentrations measured 14 years apart (4), meaning that only 16% of the variance was explained. Because serum 25(OH)D concentrations vary because of many factors, it is incorrect to assume that a single value represents the value over a long period. In the Women's Health Initiative, the mean duration of follow-up was 7.0 (standard deviation, 1.4) years (5). Thus, on the basis of other nested case-control studies, it would be expected that an inverse correlation would be found for colorectal cancer with respect to 25(OH)D concentrations but not for breast cancer, which is what was found (1). However, using the value of 0.05/year change in breast cancer relative risk (1) should have found an odds ratio of 1.29 (95% confidence interval: 1.01, 1.66) for the fully adjusted model in Table 4. This value is statistically significant. The reason for preferring nested case-control studies over case-control studies is the perception that the disease state may influence the serum 25(OH)D concentration. However, most people do not know they have cancer until so diagnosed. Thus, it seems unlikely that people with cancer would change 25(OH)D concentrations because of having cancer prior to cancer diagnosis. Those conducting cohort studies of health outcomes with respect to serum 25(OH)D concentrations should consider drawing blood samples at least every 2 years during the study and then using all samples for those used as cases or controls. The author receives funding from the UV Foundation (McLean, Virginia), Bio-Tech Pharmacal (Fayetteville, Arkansas), the Vitamin D Council (San Luis Obispo, California), and the Vitamin D Society (Canada). Conflict of interest: none declared.
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 | 0,004 | 0,023 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,001 |
| Méta-épidémiologie (sens large) | 0,003 | 0,001 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,003 | 0,001 |
| Communication savante | 0,003 | 0,002 |
| Science ouverte | 0,002 | 0,001 |
| Intégrité de la recherche | 0,033 | 0,044 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,006 | 0,009 |
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 ».