Health literacy and numeracy: key factors in cancer risk comprehension.

In this age of chronic disease and shared decision making, individuals are encouraged to contribute to decisions about health care. Health literacy, including numeracy, is requisite to meaningful participation and has been accepted as a determinant of health. The purpose of this study was to describe the influence of literacy, consisting of prose and numeracy skill, math anxiety, attained education and context of information on participant ability to comprehend Internet-based colorectal cancer prevention information. Prose, numeracy, and math-anxiety data, as well as demographic details, were collected for 140 Canadian adults, aged 50 + years. Participants had adequate prose literacy (STOFHLA) scores, high STOFHLA numeracy scores, moderate levels of health-context numeracy, poorer general-context numeracy and moderate math anxiety. There was better comprehension by participants of common (9.14/11) compared with uncommon (7.64/11) colorectal cancer information (p < 0.01). Prose literacy, numeracy, math anxiety and attained education accounted for 60% of the variation in participant comprehension scores. Numeracy, ranging from basic to advanced proficiency, is required to understand online cancer risk information. Prose literacy enhances numeracy when the subject matter is less familiar. These findings highlight the importance of presenting Web-based information that accommodates diverse health literacy and numeracy levels.