Preferences among Diseases on a Genetic Susceptibility Test for Common Health Conditions: An Ancillary Study of the Multiplex Initiative

Abstract

The potential integration of whole genome sequencing into standard healthcare practice presents an array of challenges for clinicians [1]. Among these are concerns about whether clinicians with limited time are prepared to effectively communicate about complex multi-disease genetic risk results and what key information patients need to comprehend [2–4]. In narrowing down the essential topics to be discussed with patients, it will be necessary to determine whether genomic testing should be treated as a single entity (i.e. patients would decide whether to have the test and receive all or none of the genetic risk information) or provision of each health condition on the test should be explored independently (i.e. patients would make disease-specific decisions). Although much research has examined patient decision-making for single-gene genetic tests, studies on how people choose among different diseases on a multiplex (i.e. multi-genetic variant) test are lacking. Even for newborn screening, the most widely used application of multi-disease genetic testing, research and practice guidelines focus on whether parents should be able to decline the screening test as a whole [5]. While one study did find that few healthcare providers (18.6%) support offering parents the option to choose among diseases on newborn screening tests, little consideration is typically given to this option due to pragmatic concerns [5, 6]. It is likely that there will be pressure to provide options among conditions offered on genomic tests. Typically, it is recommended that informed consent should be sought for genetic testing in the absence of overwhelming public health benefit [7]. Also, people typically prefer choice in controlling their health information, as can be seen in their support for control of what types of genetic research results are returned and desire for informed consent in biobanking research [8, 9]. How patients would make decisions among genetic tests for multiple diseases is unclear, although some research and theoretical work in health behavior suggests that they would attempt to develop an overall `gist' understanding of the test information [10]. While people have a preference for using the broadest gist representation possible, evidence indicates that nonexperts tend to use more details in their decision-making. This report is an ancillary study of a parent project, the Multiplex Initiative, where participants were offered a genetic test for 8 common health conditions [11–14]. Although the Multiplex Initiative did not allow participants to choose which health conditions would be tested, it did present an opportunity for this ancillary study to assess what disease tests participants would have chosen if given an option. The purpose of this study is to describe whether people select among individual diseases on the multiplex genetic test and, if so, characterize the correlates of those preferences.