Development of the Informing Relatives Inventory (IRI): Assessing index patients' knowledge, motivation and self-efficacy regarding the disclosure of hereditary cancer risk information to relatives

E. de Geus, C.M. Aalfs, F.H. Menko, R.H. Sijmons, M.G.E. Verdam, H.C.J.M. de Haes, E.M.A. Smets

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Abstract

Background: Despite the use of genetic services, counselees do not always share hereditary cancer information with at-risk relatives. Reasons for not informing relatives may be categorized as a lack of: knowledge, motivation, and/or self-efficacy.
Purpose: This study aims to develop and test the psychometric properties of the Informing Relatives Inventory, a battery of instruments that intend to measure counselees’ knowledge, motivation, and self-efficacy regarding the disclosure of hereditary cancer risk information to at-risk relatives.
Method: Guided by the proposed conceptual framework, existing instruments were selected and new instruments were developed. We tested the instruments’ acceptability, dimensionality, reliability, and criterion-related validity in consecutive index patients visiting the Clinical Genetics department with questions regarding hereditary breast and/or ovarian cancer or colon cancer.
Results: Data of 211 index patients were included (response rate = 62 %). The Informing Relatives Inventory (IRI) assesses three barriers in disclosure representing seven domains. Instruments assessing index patients’ (positive) motivation and self-efficacy were acceptable and reliable and suggested good criterion-related validity. Psychometric properties of instruments assessing index patients knowledge were disputable. These items were moderately accepted by index patients and the criterion-related validity was weaker.
Conclusion: This study presents a first conceptual framework and associated inventory (IRI) that improves insight into index patients’ barriers regarding the disclosure of genetic cancer information to at-risk relatives. Instruments assessing (positive) motivation and self-efficacy proved to be reliable measurements. Measuring index patients knowledge appeared to be more challenging. Further research is necessary to ensure IRI’s dimensionality and sensitivity to change.
Original languageEnglish
Pages (from-to)551-560
JournalInternational journal of behavioral medicine
Volume22
Issue number4
DOIs
Publication statusPublished - 2015

Keywords

  • international

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