title: Reproducibility of data-driven dietary patterns in two groups of adult Spanish women from different studies.
abstract: The objective of the present study was to assess the reproducibility of data-driven dietary patterns in different samples extracted from similar populations. Dietary patterns were extracted by applying principal component analyses to the dietary information collected from a sample of 3550 women recruited from seven screening centres belonging to the Spanish breast cancer (BC) screening network (Determinants of Mammographic Density in Spain (DDM-Spain) study). The resulting patterns were compared with three dietary patterns obtained from a previous Spanish case-control study on female BC (Epidemiological study of the Spanish group for breast cancer research (GEICAM: grupo Español de investigación en cáncer de mama)) using the dietary intake data of 973 healthy participants. The level of agreement between patterns was determined using both the congruence coefficient (CC) between the pattern loadings (considering patterns with a CC≥0·85 as fairly similar) and the linear correlation between patterns scores (considering as fairly similar those patterns with a statistically significant correlation). The conclusions reached with both methods were compared. This is the first study exploring the reproducibility of data-driven patterns from two studies and the first using the CC to determine pattern similarity. We were able to reproduce the EpiGEICAM Western pattern in the DDM-Spain sample (CC=0·90). However, the reproducibility of the Prudent (CC=0·76) and Mediterranean (CC=0·77) patterns was not as good. The linear correlation between pattern scores was statistically significant in all cases, highlighting its arbitrariness for determining pattern similarity. We conclude that the reproducibility of widely prevalent dietary patterns is better than the reproducibility of more population-specific patterns. More methodological studies are needed to establish an objective measurement and threshold to determine pattern similarity.
authors.affiliation: 1Cancer Epidemiology Unit,National Center for Epidemiology,Instituto de Salud Carlos III,Avenida Monforte de Lemos, 5, 28029, Madrid,Spain.
authors.forename: Adela
authors.initials: A
authors.lastname: Castelló
authors.affiliation: 1Cancer Epidemiology Unit,National Center for Epidemiology,Instituto de Salud Carlos III,Avenida Monforte de Lemos, 5, 28029, Madrid,Spain.
authors.forename: Virginia
authors.initials: V
authors.lastname: Lope
authors.affiliation: 2Consortium for Biomedical Research in Epidemiology & Public Health (CIBERESP),Instituto de Salud Carlos III,Avenida Monforte de Lemos, 5, 28029, Madrid,Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Vioque
authors.affiliation: 5Galician Breast Cancer Screening Program,Galician Regional Health Authority,C/Gregorio Hernández, 2, 4, 15011, A Coruña,Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Santamariña
authors.affiliation: 6Castile-León Breast Cancer Screening Program,General Directorate of Public Health,Avenida Sierra de Atapuerca, S/N, 09071, Burgos,Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Pedraz-Pingarrón
authors.affiliation: 7Aragón Breast Cancer Screening Program,Aragon Health Service,C/Ronda de Liberación, 1, 44002, Teruel, Zaragoza,Spain.
authors.forename: Soledad
authors.initials: S
authors.lastname: Abad
authors.affiliation: 8Navarre Breast Cancer Screening Program,Public Health Institute,C/ Leire, 15, 31003, Pamplona,Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Ederra
authors.affiliation: 9Valencian Breast Cancer Screening Program,General Directorate of Public Health,C/ Micer Mascó, 31, 46010, Valencia,Spain.
authors.forename: Dolores
authors.initials: D
authors.lastname: Salas-Trejo
authors.affiliation: 10Cancer Prevention and Control Unit,Catalonian Institute of Oncology (ICO),Avenida Gran Vía, S/N, km 2.7, 08907, L´Hospitalet de Llobregat, Barcelona,Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Vidal
authors.affiliation: 11Balearic Islands Breast Cancer Screening Program,Regional Authority for Health & Consumer Affairs,C/ Cecilio Metelo, 18, 07012, Palma de Mallorca, Islas Baleares,Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Sánchez-Contador
authors.affiliation: 1Cancer Epidemiology Unit,National Center for Epidemiology,Instituto de Salud Carlos III,Avenida Monforte de Lemos, 5, 28029, Madrid,Spain.
authors.forename: Nuria
authors.initials: N
authors.lastname: Aragonés
authors.affiliation: 1Cancer Epidemiology Unit,National Center for Epidemiology,Instituto de Salud Carlos III,Avenida Monforte de Lemos, 5, 28029, Madrid,Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Pérez-Gómez
authors.affiliation: 1Cancer Epidemiology Unit,National Center for Epidemiology,Instituto de Salud Carlos III,Avenida Monforte de Lemos, 5, 28029, Madrid,Spain.
authors.forename: Marina
authors.initials: M
authors.lastname: Pollán
mesh_terms: D000328:Adult; D001943:Breast Neoplasms; D016022:Case-Control Studies; D004032:Diet / Q000706:statistics & numerical data*; D004034:Diet Surveys / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D025341:Principal Component Analysis; D015203:Reproducibility of Results; D013030:Spain
keywords: BC breast cancer; CC congruence coefficient; Component loadings; Component scores; Congruence coefficients; DDM-Spain Determinants of Mammographic Density in Spain; Dietary patterns; EpiGEICAM Epidemiological study of the Spanish group for breast cancer research (GEICAM: grupo Español de investigación en cáncer de mama); PCA principal component analysis; Principal component analyses; Reproducibility