title: Radiographers supporting radiologists in the interpretation of screening mammography: a viable strategy to meet the shortage in the number of radiologists.
abstract: BACKGROUND
  An 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.
  
  
  METHODS
  We 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.
  
  
  RESULTS
  Radiographer'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.
  
  
  CONCLUSIONS
  Given 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.
authors.affiliation: Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Avenida Universidad No. 655, Colonia Santa María Ahuacatitlán, Cuernavaca, 62100, , Morelos, Mexico. gtorres@insp.mx.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Torres-Mejía
authors.affiliation: American Cancer Society, 250 Williams St., Atlanta, GA, 30303, USA. robert.Smith@cancer.org.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Smith
authors.affiliation: Centro de Diagnóstico Digital México-España, Secretaria de Salud Pública del Distrito Federal, Mariano Escobedo No. 148 col. Anáhuac, Ciudad de México D. F., 11320, Mexico. mlcf_13@yahoo.com.mx.
authors.forename: María de la Luz
authors.initials: Mde L
authors.lastname: Carranza-Flores
authors.affiliation: Group Health Research Institute, Group Health Cooperative, 1730 Minor Ave #1600, Seattle, WA, 98101, USA. bogart.t@ghc.org.
authors.forename: Andy
authors.initials: A
authors.lastname: Bogart
authors.affiliation: Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Avenida Universidad No. 655, Colonia Santa María Ahuacatitlán, Cuernavaca, 62100, , Morelos, Mexico. mat_pichu@hotmail.com.
authors.forename: Louis
authors.initials: L
authors.lastname: Martínez-Matsushita
authors.affiliation: Group Health Research Institute, Group Health Cooperative, 1730 Minor Ave #1600, Seattle, WA, 98101, USA. dmiglioretti@phs.ucdavis.edu.|Division of Biostatistics, Department of Public Health Sciences, School of Medicine, University of California, 1 Shields Ave, Davis, CA, 95616, USA. dmiglioretti@phs.ucdavis.edu.
authors.forename: Diana L
authors.initials: DL
authors.lastname: Miglioretti
authors.affiliation: Department of Epidemiology and Biostatistics and the General Internal Medicine Section, University of California, 4150 Clement St, San Francisco, CA, 94121, USA. karla.Kerlikowske@ucsf.edu.|Department of Veterans Affairs, University of California, 4150 Clement St, San Francisco, CA, 94121, USA. karla.Kerlikowske@ucsf.edu.
authors.forename: Karla
authors.initials: K
authors.lastname: Kerlikowske
authors.affiliation: Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Avenida Universidad No. 655, Colonia Santa María Ahuacatitlán, Cuernavaca, 62100, , Morelos, Mexico. ortega.caro@gmail.com.
authors.forename: Carolina
authors.initials: C
authors.lastname: Ortega-Olvera
authors.affiliation: Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Avenida Universidad No. 655, Colonia Santa María Ahuacatitlán, Cuernavaca, 62100, , Morelos, Mexico. agersomnia@gmail.com.
authors.forename: Ernesto
authors.initials: E
authors.lastname: Montemayor-Varela
authors.affiliation: Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Avenida Universidad No. 655, Colonia Santa María Ahuacatitlán, Cuernavaca, 62100, , Morelos, Mexico. aangelica@insp.mx.
authors.forename: Angélica
authors.initials: A
authors.lastname: Angeles-Llerenas
authors.affiliation: Dirección de Economía de la Salud, Instituto Nacional de Salud Pública, Avenida Universidad No. 655, Colonia Santa María Ahuacatitlán, CP. 62100, Cuernavaca, Morelos, Mexico. sbautista@insp.mx.
authors.forename: Sergio
authors.initials: S
authors.lastname: Bautista-Arredondo
authors.affiliation: Dirección de Economía de la Salud, Instituto Nacional de Salud Pública, Avenida Universidad No. 655, Colonia Santa María Ahuacatitlán, CP. 62100, Cuernavaca, Morelos, Mexico. gilberto.sanchez@insp.mx.
authors.forename: Gilberto
authors.initials: G
authors.lastname: Sánchez-González
authors.affiliation: Hospital de Oncología, Centro Médico Siglo XXI, Instituto Mexicano del Seguro Social, Av. Cuauhtémoc 330, Cuauhtemoc Doctores, Ciudad de México, D.F. 06720, Mexico. ogmartinez@salud.gob.mx.
authors.forename: Olga G
authors.initials: OG
authors.lastname: Martínez-Montañez
authors.affiliation: Federación Mexicana de Colegios de Ginecología y Obstetricia, Nueva York 38, Col. Nápoles, Benito Juárez, Ciudad de México, D.F. 03810, Mexico. suscanga@prodigy.net.mx.
authors.forename: Santos R
authors.initials: SR
authors.lastname: Uscanga-Sánchez
authors.affiliation: Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Avenida Universidad No. 655, Colonia Santa María Ahuacatitlán, Cuernavaca, 62100, , Morelos, Mexico. elazcano@insp.mx.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Lazcano-Ponce
authors.affiliation: Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Avenida Universidad No. 655, Colonia Santa María Ahuacatitlán, Cuernavaca, 62100, , Morelos, Mexico. mhernan@insp.mx.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Hernández-Ávila
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology; D003663:Decision Trees; D055088:Early Detection of Cancer; D005260:Female; D006280:Health Workforce; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008327:Mammography / Q000592:standards; D008403:Mass Screening; D008800:Mexico / Q000453:epidemiology; D008875:Middle Aged; D008962:Models, Theoretical; D015588:Observer Variation; D010820:Physicians; D011361:Professional Competence; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult