Correlates and geographic patterns of knowledge that physical activity decreases cancer risk.

While many lifestyle-related cancer risk factors including tobacco use, poor diet, and sun exposure are well recognized by the general public, the role of physical activity in decreasing cancer risk is less recognized. Studies have demonstrated gender-, race/ethnicity-, and age-based disparities in cancer risk factor knowledge; however, beliefs and geographic factors that may be related to knowledge are under-examined. In this study, we analyzed data from the 2008 Health Information National Trends Survey to determine correlates of knowledge of the relationship between physical activity and reduced cancer risk in the adult US population. We generated geographic information system maps to examine the geographic distribution of this knowledge. Results revealed that there is confusion among US adults about the relationship between physical activity and cancer risk: Respondents who believed that cancer is not preventable had significantly lower odds of knowing that physical activity reduces cancer risk (p < .001) whereas respondents who believed that cancer is caused by one's behavior had almost two times the odds of knowing that physical activity reduces cancer risk (p < .001). Those who were aware of current physical activity guidelines were also significantly more likely to know that physical activity reduces cancer risk (p < .01). Observed geographic variability in knowledge was consistent with geographic trends in obesity and physical inactivity. Correlates of cancer risk factor knowledge point to opportunities for targeted interventions.