Radiographers supporting radiologists in the interpretation of screening mammography: a viable strategy to meet the shortage in the number of radiologists.

BackgroundAn alternative approach to the traditional model of radiologists interpreting screening mammography is necessary due to the shortage of radiologists to interpret screening mammograms in many countries.MethodsWe evaluated the performance of 15 Mexican radiographers, also known as radiologic technologists, in the interpretation of screening mammography after a 6 months training period in a screening setting. Fifteen radiographers received 6 months standardized training with radiologists in the interpretation of screening mammography using the Breast Imaging Reporting and Data System (BI-RADS) system. A challenging test set of 110 cases developed by the Breast Cancer Surveillance Consortium was used to evaluate their performance. We estimated sensitivity, specificity, false positive rates, likelihood ratio of a positive test (LR+) and the area under the subject-specific Receiver Operating Characteristic (ROC) curve (AUC) for diagnostic accuracy. A mathematical model simulating the consequences in costs and performance of two hypothetical scenarios compared to the status quo in which a radiologist reads all screening mammograms was also performed.ResultsRadiographer's sensitivity was comparable to the sensitivity scores achieved by U.S. radiologists who took the test but their false-positive rate was higher. Median sensitivity was 73.3 % (Interquartile range, IQR: 46.7-86.7 %) and the median false positive rate was 49.5 % (IQR: 34.7-57.9 %). The median LR+ was 1.4 (IQR: 1.3-1.7 %) and the median AUC was 0.6 (IQR: 0.6-0.7). A scenario in which a radiographer reads all mammograms first, and a radiologist reads only those that were difficult for the radiographer, was more cost-effective than a scenario in which either the radiographer or radiologist reads all mammograms.ConclusionsGiven the comparable sensitivity achieved by Mexican radiographers and U.S. radiologists on a test set, screening mammography interpretation by radiographers appears to be a possible adjunct to radiologists in countries with shortages of radiologists. Further studies are required to assess the effectiveness of different training programs in order to obtain acceptable screening accuracy, as well as the best approaches for the use of non-physician readers to interpret screening mammography

Desarrollo de una Nueva Solución Compacta a la Cinemática de Manipuladores Robóticos basada en Cuaterniones Duales

ResumenEste trabajo presenta una nueva solución compacta basada en cuaterniones duales para el desarrollo de la cinemática de manipuladores robóticos. Se plantea el desarrollo de una herramienta en forma completa para poder observar claramente su correlación con el método de las matrices de transformación homogénea derivadas a partir de los parámetros de Denavit-Hartenberg. Se proponen herramientas para simplificar el uso de los cuaterniones duales para la obtención del modelo cinemático de mecanismos de cadena abierta definiendo la regla de la cadena aplicada a estos. Finalmente se ilustra su aplicación a un par de casos de estudio

Survey on the use of premix insulin analogues in diabetes mellitus type 1 and 2 in Mexico [Encuesta sobre el uso de premezclas de an�logos de insulinas en pacientes con diabetes en M�xico]

Background: There are several publications related to the use of premixed insulin analogs in Type 1 and 2 Diabetes Mellitus, however, there was no information about its use in the Mexican clinical practice. Materials and methods: A survey was conducted to 48 physicians experts in Diabetes Mellitus. They were endocrinologists (62%), Internists (32) and diabetologists (6%). Results: Twenty-four percent of the specialists pointed out that more than half of the patients who consult by the first time do not respond to treatment with oral hypoglycemic medication. A high number of patients treated with insulin reach glycemic control goals. Most of the experts treat more than half of their patients with insulin. Sixty-six percent of the experts use premixed insulin analogs in their patients with type 1 Diabetes, and a high percentage use them in type 2 Diabetes. Most of the expert physicians recommend the use of premixed insulin analogs as the first line treatment in their patients diagnosed with Type 2 Diabetes. Conclusions: Premixed insulin analogs are widely accepted by patients because they offer a complete coverage of their metabolic requirements, reducing the number of daily injections. In type 1 Diabetes, premixed insulin analogs will be used to improve metabolic control and to strengthen compliance. This document describes the use of premixed insulin analogs in the treatment of Diabetes Mellitus in Mexico

Survey on the use of premix insulin analogues in diabetes mellitus type 1 and 2 in Mexico [Encuesta sobre el uso de premezclas de análogos de insulinas en pacientes con diabetes en México]

Background: There are several publications related to the use of premixed insulin analogs in Type 1 and 2 Diabetes Mellitus, however, there was no information about its use in the Mexican clinical practice. Materials and methods: A survey was conducted to 48 physicians experts in Diabetes Mellitus. They were endocrinologists (62%), Internists (32) and diabetologists (6%). Results: Twenty-four percent of the specialists pointed out that more than half of the patients who consult by the first time do not respond to treatment with oral hypoglycemic medication. A high number of patients treated with insulin reach glycemic control goals. Most of the experts treat more than half of their patients with insulin. Sixty-six percent of the experts use premixed insulin analogs in their patients with type 1 Diabetes, and a high percentage use them in type 2 Diabetes. Most of the expert physicians recommend the use of premixed insulin analogs as the first line treatment in their patients diagnosed with Type 2 Diabetes. Conclusions: Premixed insulin analogs are widely accepted by patients because they offer a complete coverage of their metabolic requirements, reducing the number of daily injections. In type 1 Diabetes, premixed insulin analogs will be used to improve metabolic control and to strengthen compliance. This document describes the use of premixed insulin analogs in the treatment of Diabetes Mellitus in Mexico

Rivaroxaban with or without aspirin in stable cardiovascular disease

BACKGROUND: We evaluated whether rivaroxaban alone or in combination with aspirin would be more effective than aspirin alone for secondary cardiovascular prevention. METHODS: In this double-blind trial, we randomly assigned 27,395 participants with stable atherosclerotic vascular disease to receive rivaroxaban (2.5 mg twice daily) plus aspirin (100 mg once daily), rivaroxaban (5 mg twice daily), or aspirin (100 mg once daily). The primary outcome was a composite of cardiovascular death, stroke, or myocardial infarction. The study was stopped for superiority of the rivaroxaban-plus-aspirin group after a mean follow-up of 23 months. RESULTS: The primary outcome occurred in fewer patients in the rivaroxaban-plus-aspirin group than in the aspirin-alone group (379 patients [4.1%] vs. 496 patients [5.4%]; hazard ratio, 0.76; 95% confidence interval [CI], 0.66 to 0.86; P<0.001; z=−4.126), but major bleeding events occurred in more patients in the rivaroxaban-plus-aspirin group (288 patients [3.1%] vs. 170 patients [1.9%]; hazard ratio, 1.70; 95% CI, 1.40 to 2.05; P<0.001). There was no significant difference in intracranial or fatal bleeding between these two groups. There were 313 deaths (3.4%) in the rivaroxaban-plus-aspirin group as compared with 378 (4.1%) in the aspirin-alone group (hazard ratio, 0.82; 95% CI, 0.71 to 0.96; P=0.01; threshold P value for significance, 0.0025). The primary outcome did not occur in significantly fewer patients in the rivaroxaban-alone group than in the aspirin-alone group, but major bleeding events occurred in more patients in the rivaroxaban-alone group. CONCLUSIONS: Among patients with stable atherosclerotic vascular disease, those assigned to rivaroxaban (2.5 mg twice daily) plus aspirin had better cardiovascular outcomes and more major bleeding events than those assigned to aspirin alone. Rivaroxaban (5 mg twice daily) alone did not result in better cardiovascular outcomes than aspirin alone and resulted in more major bleeding events