Supplementing Disease Risk Information for Type 2 Diabetes and Coronary Heart Disease with Polygenic Risk Scores: Testing a Health Action Process Approach–Inspired Path Model to Predict Health Behavior

Abstract Background Advances in genotyping have heightened interest in using polygenic risk scores (PRS) to predict complex diseases such as type 2 diabetes (T2D) and coronary heart disease (CHD). However, the psychological effects of receiving a PRS have been examined only to a limited extent, with a notable absence of studies grounded in health psychology theory. The present study investigated whether incorporating PRS into risk communication influences health behaviors, drawing on a model inspired by the Health Action Process Approach (HAPA). Method The sample was collected in a randomized experimental design ( N = 1494), in which 751 participants received a PRS result and 743 did not. Multigroup structural equation modeling was used to estimate HAPA-inspired path models and test whether the path coefficients differed between the study groups. The models examined how perceived risk, self-efficacy, and outcome expectancies were related to intentions to increase physical activity (PA) and fruit and vegetable intake (FVI), and how these intentions, in turn, were related to subsequent behavior. Results Multigroup analysis revealed small, non-significant differences between groups, suggesting that the inclusion of PRS did not substantially alter the functioning of the motivational pathways proposed by HAPA or the resulting health behaviors. Conclusion Supplementing traditional disease risk information with PRS does not appear to significantly disrupt the motivational processes typically associated with health behavior change. These findings align with prior research on the HAPA model as well as with studies examining the psychological impact of receiving PRS.