Explaining the Lackluster Impacts of Colorectal Cancer Risk Calculators in Consideration of Perceived Susceptibility and Gender: Experimental Study (Preprint)

Abstract

Risk calculators are increasingly being used to promote cancer awareness and improve compliance with screening tests. Research concerning the effects of colorectal cancer (CRC) risk calculators on the intention to undergo CRC screening, however, has been limited. Some studies have shown lackluster impacts of CRC risk calculators, reporting that people tend to lower their risk perception after receiving personalized assessments from such calculators.

We conducted an experiment to examine the mechanisms through which CRC risk calculators might influence individuals’ intentions to undergo CRC screening by examining the role of perceived susceptibility to CRC as a mediating mechanism for the effect of receiving CRC risk assessment results. We also investigate the moderating effect of gender.

Participants (N = 128) completed a series of CRC risk calculator input questions and were randomly assigned to treatment (CRC risk calculator results immediately displayed) and control (CRC risk calculator results made available after the experiment ended) groups. Both groups completed a CRC risk calculator and responded to questions regarding perceived susceptibility to CRC and their intention to get screened.

We found that men and women react differently to receiving CRC risk calculator results. Specifically, for men (n=46), the direct effect of receiving CRC risk calculator results on intention to undergo CRC screening was positive (β=1.05, confidence interval (CI): 0.24 – 1.97). The direct effect was not significant among women (n=82; β=-.03, CI: -0.77 – 0.70). For women, perceived susceptibility to CRC mediates the relationship (indirect effect β=-.53, CI: -0.91 - -0.21); displaying CRC risk calculator results reduce perceived susceptibility to CRC, which in turn reduces the intention to sign up for CRC screening. Such mediating relationship was not significant among men (indirect effect β=-.10, CI: -0.47 – 0.18).

The implications of this work are that men and women respond through different mechanisms to receiving CRC risk calculator results and that gender differences should be considered when promoting CRC screening.