Multiplex Genetic Testing
Understanding Psychological Factors
New genetic “multiplex” testing reveals the risks for multiple health conditions, but little is understood about the psychological factors that affect whether healthy young adults will undergo the test. Research by Professor Samuel Woodford and colleagues assessed the multiplex genetic testing model (MGTM) - which delineates worry, perceived severity, perceived risk, response efficacy and attitudes toward testing - as a predictor of interest and ultimately actual participation in multiplex genetic testing.
The team used structural equation modeling to test the combined effects of these latent variables on multiplex genetic testing. It built upon data collected from the Multiplex Initiative, a study designed to examine the uptake of multi-gene testing for eight common conditions: type 2 diabetes, coronary heart disease, high blood cholesterol, high blood pressure, osteoporosis, lung cancer, colorectal cancer, and malignant melanoma.
Findings did, in fact, support the usefulness of the MGTM in predicting test uptake. Having a positive attitude toward testing was the strongest predictor. Participants grouped perceptions about health threats generated from the eight conditions into two domains: cancers and metabolic conditions. This indicates that with respect to risk, severity and worry, respondents thought of cancer related risks differently than they considered metabolic disease risks. This was not true, however, for attitudes toward multiplex testing and response efficacy where respondents did not appear to perceive a difference in the disease risks.
In regard to the relationship between attitude about avoiding diseases and the intention to undergo the test, Woolford found that response efficacy, the belief that multiplex testing could reduce an individual’s risk of getting any of the diseases (even though in reality a test cannot do this directly), was the sole predictor of an individual’s attitudes toward multiplex testing, which in turn was the best predictor of the intent to undergo testing. In turn, intent to get tested was a strong predictor of actually getting tested.
The researchers consider it remarkable that while perceived risk of the metabolic conditions played a role in response efficacy, a perceived risk for cancer did not have a significant impact. This implies that while perceived risk, perceived severity and worry are key to the initial processing of information about a health threat, they are less important in predicting response efficacy and do not directly predict attitudes toward testing.
The researchers’ results offer powerful evidence of a significant role for attitudes in predicting intention to undergo multiplex testing and ultimately test uptake. As multiplex testing becomes more commonly integrated into general medical care, these results will help frontline healthcare providers interact with patients to help ease anxiety about multiplex testing and determine ways to help them recognize the value in multiplex testing.
Perceived severity and worry are key to the initial processing of information about a health threat.