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

• Published in: International journal of behavioral medicine 2015-08, Vol.22 (4), p.551-560
• Main Authors: de Geus, Eveline, Aalfs, Cora M., Menko, Fred H., Sijmons, Rolf H., Verdam, Mathilde G. E., de Haes, Hanneke C. J. M., Smets, Ellen M. A.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Cancer; Families & family life; Family Medicine; Female; General Practice; Genetic counseling; Health Knowledge, Attitudes, Practice; Health Psychology; Heredity; Humans; Male; Medicine; Medicine & Public Health; Middle Aged; Motivation; Neoplasms - genetics; Patient education; Psychometrics; Quantitative psychology; Reproducibility of Results; Risk; Risk factors; Self Efficacy; Truth Disclosure; Young Adult
• ISSN: 1070-5503; 1532-7558
• DOI: 10.1007/s12529-014-9455-x

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.