Investigating Public Enthusiasm for Mammography Screening in Denmark

Study Overview
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Brief Summary
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Based on an American study by Scherer et al., it is hypothesized that some women will make irrational choices regarding their participation in mammography screening. Therefore, the aim is to estimate the prevalence of Danish women having an irrational preference for mammography screening even when it confers no benefits, but only harms.

Detailed Description
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The prevalence of women making an irrational decision will be compared to the participation rate in the Danish screening program. The study population will consist of a random sample of women aged 44-49. Similar to the American study, two types of information will be compared (detailed vs. non-detailed information about the harms of screening). Participants will be randomised to one of two information groups. Based on the American study, it is assumed that the willingness to participate in the hypothetical screening program will be 40 percent. To achieve the desired precision in this study, a standard error of 2.5 percent is required corresponding to a confidence interval spanning approximately 35-45 percent. This will require 384 women in each group, corresponding to a total study population of 768. The survey will be sent electronically (using e-Boks) with a link to access the online survey trial. The survey will consist of screening and cancer related questions as well as questions on age, education, and health literacy. Five questions on appraisal of health information from the Health Literacy Questionnaire will also be included. After the data collection, data will be linked to data on income, residence, civil status, education, breast cancer diagnosis, and information on whether a participant is immigrant, descendent or of Danish origin. The original plan for the main analysis was to compare the two groups of women randomized to different information groups (detailed vs. non-detailed information about the harms of screening). However, due to lower participation rate and therefore smaller sample size than expected, information group was disregarded in the main analysis. The two groups will still be compared in a secondary analysis. This decision was made before getting access to data from the questionnaire.

Official Title
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Investigating Public Enthusiasm for Mammography Screening in Denmark

Conditions
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Decision Making, Information Seeking Behavior, Breast Neoplasm Female, Mammography Screening

Intervention / Treatment
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* Behavioral: Information about hypothetical mammography screening without benefits


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Residence: Central Denmark Region Exclusion Criteria: -

Ages Eligible for Study
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Minimum Age: 44 Years
Maximum Age: 49 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Health Services Research
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Detailed information about screening harms<br> | Behavioral: Information about hypothetical mammography screening without benefits<br>* We will present an online questionnaire with two types of information on the harms of screening. Then we will compare the prevalence of irrational decisions in the two arms.<br>|
| Other: Non-detailed information about screening harms<br> | Behavioral: Information about hypothetical mammography screening without benefits<br>* We will present an online questionnaire with two types of information on the harms of screening. Then we will compare the prevalence of irrational decisions in the two arms.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Irrational preference | Willingness to participate in mammography screening with no benefits on morbidity or mortality, only harms. Investigated by sending out questionnaire once to all women. | The outcome is assessed when women answer the questionnaire which is sent out at the same time to all women. The invited women will have 2 months to answer the questionnaire (it should only take around 15 minutes to answer). Planned from November 2020. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Breast cancer, Mammography screening, Decision Making, Information Seeking Behavior