RISK COMPREHENSION OF ONLINE COLORECTAL CANCER INFORMATION: AN ASSESSMENT OF HEALTH NUMERACY

Abstract

Introduction: Colorectal cancer is the third leading cause of cancer among Canadians and the second leading cause of cancer deaths. In this age of chronic disease and shared decision-making, individuals are encouraged and expected to contribute to decisions about healthcare. Increasingly, Canadians rely on the Internet as an access point to healthcare information. Health literacy, particularly adequate numeracy skill, occupies a central role within cancer care communication and is requisite to meaningful participation in risk-based decision-making. Despite this, numeracy has attracted little research attention. Consequently, the primary objective of this study was to investigate the influence of health numeracy skills, health prose literacy, math anxiety, attained education, and context of information on participant ability to comprehend Internet based colorectal cancer risk information. Method: Demographic details were collected on 140 older Canadian volunteers. Health literacy (prose and numeracy), and math anxiety scores were also obtained. Prose literacy was measured by the STOFHLA whereas numeracy was assessed using three instruments (general context numeracy, health context numeracy, and the STOFHLA). Math anxiety was measured by the Abbreviated Math Anxiety Scale (AMAS). The assessment of participant risk comprehension was based on two web pages of colorectal cancer information. The two web pages were chosen from the Canadian Cancer Society; one represented ‘common’ information and the other represented ‘uncommon’ information. Multiple regression analysis was employed to determine the influence of explanatory variables on participant risk comprehension. Results: The majority of older adults (91%) in this convenience sample had ‘adequate’ functional health literacy as measured by the STOFHLA. Participants revealed wide variation of numeric competency with high STOFHLA numeracy scores, moderate levels of health context numeracy and math anxiety, but poorer general context numeracy skill. The mean score for participant comprehension of colorectal cancer risk was 16.8/22. There was a significant difference between risk comprehension scores on ‘common’ (9.14/11) and ‘uncommon’ (7.64/11) web-based cancer information with better comprehension of the ‘common’ information. Approximately 60% of the variation in participant risk comprehension scores was explained by the prose health literacy, general context numeracy, health context numeracy, STOFHLA numeracy, math anxiety, and level of education. Additional regression modeling highlighted the significance of health context numeracy skill for both ‘common’ and ‘uncommon’ cancer information and the need for the combined skills of prose health literacy and numeracy for comprehension of ‘uncommon’ web-based cancer risk information. Conclusion: Adequate health numeracy skill is a necessary component for understanding online cancer information. A spectrum of health numeracy skill ranging from basic to more advanced proficiency is needed for comprehension of cancer risk information. For comprehension of less familiar subject matter, ‘content’ knowledge or enhanced prose health literacy skill, jointly with health numeracy skill, is required. This research underscores the need for continued investigation of the role of health literacy (prose and numeric) in the comprehension of online cancer information among diverse groups of healthcare consumers. These findings highlight the need for continued research directed at concept clarification and concept modeling of prose health literacy and numeracy. Research focusing on the development of a comprehensive health numeracy assessment instrument is recommended. Also, these findings have important implications for health educators in designing online cancer information. Cancer information specialists and web designers are encouraged to exploit the versatility of the Internet in order to construct web-based cancer information to accommodate the continuum of health literacy/numeracy skill that currently exists.