Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2019 Mar 19;7(1):17.
doi: 10.1186/s40359-019-0291-2.

Development of the Informed Choice in Mammography Screening Questionnaire (IMQ): factor structure, reliability, and validity

Maren Reder  1   2 , Eva-Maria Berens  3 , Jacob Spallek  4 , Petra Kolip  5
Affiliations

Development of the Informed Choice in Mammography Screening Questionnaire (IMQ): factor structure, reliability, and validity

Maren Reder et al. BMC Psychol. .

Abstract

Background: Informed choice is of ethical and practical importance in mammography screening. To assess the level to which decisions regarding such screening are informed is thus imperative, but no specific instrument has been available to measure informed choice in the German mammography screening programme. The aims of this study were to develop the Informed Choice in Mammography Screening Questionnaire (IMQ) and to find first evidence for the factor structure, reliability and validity of its different components.

Methods: The IMQ was sent to 17.349 women aged 50 in Westphalia-Lippe, Germany. The instrument has been developed after consideration of (1) the results of qualitative interviews on decision making in the mammography screening programme, (2) relevant literature on other informed choice instruments and (3) a qualitative study on influencing factors. The IMQ comprises 3 scales (attitude, norms, and barriers), 1 index (knowledge) and singular items covering intention to participate and sociodemographic variables. To assess the psychometric properties of the components of the IMQ, confirmatory factor and item response theory analyses were conducted. Additionally, reliability, validity and item statistics were assessed.

Results: 5.847 questionnaires were returned (response rate 33.7%). For attitude, the confirmatory factor analysis supported a one-factor structure. For norms, the model fit was not acceptable. Reliability levels were good with a Cronbach's α of.793 for attitude (4 items) and.795 for norms (5 items). For barriers, 9 items were deleted because of low discrimination indices; 6 items remained. The hypothesised assumption-subscale and the importance-subscale were confirmed, but these subscales showed poor reliabilities with Cronbach's α=.525 (4 items) and.583 (2 items). For the knowledge index, item response theory analysis showed that 6 out of 7 items were suitable. Hypotheses concerning the correlations between the different components were confirmed, which supported their convergent and divergent validity.

Conclusion: The results of this study demonstrated that the IMQ is a multidimensional instrument. Further development of the barriers and norms scales is necessary. The IMQ can be utilised to assess the level of informed choices as well as influencing factors.

Keywords: Confirmatory factor analysis; Informed choice; Mammography screening; Reliability; Validity.

PubMed Disclaimer

Conflict of interest statement

Authors’ information

MR is doctoral student at the Bielefeld School of Public Health and researcher at the Institute of Psychology, University of Hildesheim. E-MB is researcher at the Bielefeld School of Public Health. JS is professor for public health at Brandenburg University of Technology Cottbus-Senftenberg. PK is professor for prevention and health promotion at the Bielefeld School of Public Health.

Ethics approval and consent to participate

The study was cleared by the ethical committee of the Medical Faculty of Muenster University (2012-268-f-S). Participants were informed about the purpose of the study, the voluntary and anonymous nature of the data collection, and the analysis procedure. Written informed consent was obtained.

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Figures

Fig. 1
Fig. 1
Item characteristic curves of the knowledge items (2-parameter-logistic-model)
See this image and copyright information in PMC

References

    1. Haberland J, Bertz J, Wolf U, Ziese T, Kurth B-M. German cancer statistics 2004. BMC Cancer. 2010;10:52. doi: 10.1186/1471-2407-10-52. - DOI - PMC - PubMed
    1. Mammographie, K (2009). Evaluationsbericht 2005–2007 - Ergebnisse des Mammographie-Screening-Programms in Deutschland. https://www.g-ba.de/downloads/17-98-2731/2009-09-21-Evaluationsbericht.pdf. Accessed 12 Nov 2014.
    1. Gøtzsche PC, Jørgensen KJ. Screening for breast cancer with mammography. Cochrane Database Syst Rev. 2013;6:001877. - PMC - PubMed
    1. Bond M, Pavey T, Welch K, Cooper C, Garside R, Dean S, Hyde C. Systematic review of the psychological consequences of false-positive screening mammograms. Health Technol Assess. 2013;17(13):1–170. doi: 10.3310/hta17130. - DOI - PMC - PubMed
    1. Welch HG, Black WC. Overdiagnosis in cancer. J Natl Cancer Inst. 2010;102(9):605–13. doi: 10.1093/jnci/djq099. - DOI - PubMed

Publication types