title: Proportion of women with self-reported opportunistic mammography before organized screening.
abstract: BACKGROUND
  In Finland, organized nationwide breast cancer (BC) screening is biennially offered for women aged 50-69 years. The aim was to estimate, for the first time in Finland, the proportion of women having opportunistic mammography at age less than 50 years and to investigate the role of BC family history and educational level for having opportunistic mammography.
  
  
  METHODS
  The study material comprises two self-administered, population-based questionnaires from altogether 9845 healthy women; 4666 women in Women's Health and Use of Hormone-study (WHH survey), and 5179 in Breast Cancer Screening, Lifestyle and Quality of Life-study (EET survey). We report the estimated proportions of women with self-reported opportunistic mammography at age <50 years in percentages.
  
  
  RESULTS
  The response percentages were 53% in the WHH survey and 52% in the EET survey. The percentage of women with self-reported opportunistic mammography was 66.7% and 60.4% in the two questionnaires, respectively. Regarding family history of BC, 76.5% and 68.5% of women with BC family history in a first degree relative reported having had a mammography, in contrast to that of 65.5% and 59.4% of women without BC family history. Opportunistic mammography was also more common in women with >12 years of education than women with ≤12 years of education.
  
  
  CONCLUSIONS
  Overall, some two thirds of the women reports of having had a mammography before organized screening started. Opportunistic mammography was more likely among women with a positive family history of BC in a first degree relative as well as more than 12 years of education. Regardless of low response activity, the observed popularity of opportunistic mammography before organized screening gives ground for further evaluation of the related health care practices. Screening activity before organized screening also influences the evaluation of the screening program, as women have different, indeterminate histories of pre-organized screening.
authors.affiliation: a Finnish Cancer Registry, Institute for Statistical and Epidemiological Cancer Research , Helsinki , Finland ;
authors.forename: Sanna
authors.initials: S
authors.lastname: Heikkinen
authors.affiliation: a Finnish Cancer Registry, Institute for Statistical and Epidemiological Cancer Research , Helsinki , Finland ;
authors.forename: Joonas
authors.initials: J
authors.lastname: Miettinen
authors.affiliation: b Faculty of Medicine, Department of Public Health , University of Helsinki , Helsinki , Finland ;
authors.forename: Markku
authors.initials: M
authors.lastname: Koskenvuo
authors.affiliation: a Finnish Cancer Registry, Institute for Statistical and Epidemiological Cancer Research , Helsinki , Finland ;
authors.forename: Riikka
authors.initials: R
authors.lastname: Huovinen
authors.affiliation: a Finnish Cancer Registry, Institute for Statistical and Epidemiological Cancer Research , Helsinki , Finland ;|b Faculty of Medicine, Department of Public Health , University of Helsinki , Helsinki , Finland ;
authors.forename: Janne
authors.initials: J
authors.lastname: Pitkäniemi
authors.affiliation: a Finnish Cancer Registry, Institute for Statistical and Epidemiological Cancer Research , Helsinki , Finland ;
authors.forename: Tytti
authors.initials: T
authors.lastname: Sarkeala
authors.affiliation: a Finnish Cancer Registry, Institute for Statistical and Epidemiological Cancer Research , Helsinki , Finland ;|c School of Health Sciences , University of Tampere , Tampere , Finland .
authors.forename: Nea
authors.initials: N
authors.lastname: Malila
mesh_terms: D000368:Aged; D001294:Attitude to Health; D001943:Breast Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000453:epidemiology; D016022:Case-Control Studies; D055088:Early Detection of Cancer / Q000706:statistics & numerical data; D005260:Female; D005387:Finland / Q000453:epidemiology; D006306:Health Surveys; D006801:Humans; D008327:Mammography / Q000706:statistics & numerical data*; D008403:Mass Screening / Q000706:statistics & numerical data; D008875:Middle Aged; D057566:Self Report