Health numeracy and understanding of risk among older American Indians and Alaska Natives.

American Indian and Alaska Native people suffer extreme health disparities and remain underrepresented in health research. This population needs adequate numeracy skills to make informed decisions about health care and research participation, yet little is known about their numeracy skills. Participants were 91 American Indian and Alaska Native elders who completed an anonymous survey that measured numeracy and the correlation between framing of risk and comprehension of risk. The authors measured numeracy by a previously developed 3-item scale that assessed basic probability skills and the ability to manipulate percentages and proportions. Risk comprehension was measured by 3 items on treatment benefits, which were variously framed in terms of relative risk reduction, absolute risk reduction, and number needed to treat. Framing in terms of relative risk was associated with higher odds of correct interpretation compared to absolute risk (OR=1.8, 95% CI=1.2-2.9) and number needed to treat (OR=2.0, 95% CI=1.2-3.5). This association persisted after adjusting for covariates, including baseline numeracy skills. Our results underscore the need for clinicians to consider how health information is framed and to check carefully for understanding when communicating risk information to patients.