Factors influencing intention to obtain a genetic test for colon cancer risk: a population-based study

Abstract

Background: The availability of genetic testing for cancer risk has prompted an examination of the intention of the general public to undergo testing. This study expands a previous psychosocial model of factors influencing intention to undergo genetic testing for cancer in general to the context of colon cancer.

Methods: A sample of 1,836 adult residents of Vermont, New Hampshire, and Maine were interviewed via telephone. The survey instrument included measures derived from the Health Belief Model and additional psychosocial measures adapted from the literature. Structural Equation Modeling techniques were used to examine factors associated with the likelihood to undergo genetic testing.

Results: Perceived barriers and benefits of testing, and perceived susceptibility to colon cancer had direct associations with likelihood. Optimism and pessimism had both direct and indirect effects. Age, socioeconomic status, family history, and awareness of genetic testing had indirect effects, and acted through the other factors. The model explained 22% of the variance in likelihood.

Conclusions: Perceived barriers, benefits, susceptibility, optimism, and pessimism directly influenced likelihood, and may also mediate the effect of background factors examined in this study. These findings suggest effective educational strategies to improve decision-making concerning genetic testing for colon cancer risk in the general population.