A mixed methods study of the relationship between illness perceptions and the cascade genetic screening process in hypertophic cardiomyopathy, and clinical research portfolio

Abstract

Background: Hypertrophic Cardiomyopathy (HCM) a relatively common inherited cardiac disease, symptoms include breathlessness, palpitations, chest pain and more rarely, sudden cardiac death. Cascade genetic screening where individuals already diagnosed with HCM are tasked with communicating genetic risk to relatives is an increasingly viable means of confirming HCM associated gene carriers and identifying their at-risk relatives, however uptake of such testing is suboptimal. The common-sense model of illness perceptions has frequently been used to understand behaviours linked to health within individuals (Leventhal et al., 1980). Less is understood about how these perceptions may influence communication of health information to others. Aims: The primary aim of the study was to explore whether illness perceptions of those who first undergo genetic testing for the HCM gene mutation predict uptake of cascade genetic screening by at-risk first-degree relatives. Methods: A mixed method, single centre, cross-sectional design was employed. Fifty-seven individuals with HCM undergoing genetic testing completed measures of illness perceptions, closeness to relatives and perceived self-efficacy. Data on uptake of cascade screening by respective first-degree relatives was obtained from the host clinic. Semi-structured interviews were conducted on a sub-group of six individual focusing on those who had low associated illness identity. Transcripts were explored using Thematic Analysis (TA). Results: Overall first-degree relative uptake within the sample was 65%. A linear regression indicated that relatives of individuals who perceived HCM to be a more acute condition were 13% more likely to have undergone genetic screening. Thematic analyses of interview transcripts yielded three superordinate themes: The confusing HCM experience, the reasons for testing and doubts about testing. Conclusions: The findings of this study should be considered with caution due to the limits placed on the analysis as a result of the small sample recruited. However, the findings of the analysis indicating a link between the illness perceptions of the individual tasked with communicating risk to relatives and subsequent relative uptake merits further investigation