Limited literacy and mortality in the elderly: The health, aging, and body composition study

Background: While limited literacy is common and its prevalence increases with age, no prospective study has assessed whether limited literacy is associated with mortality in older adults. Objective: To assess the association of limited literacy with mortality. Design and Setting: Five-year prospective study from 1999 to 2004 of community-dwelling elders from Memphis, TN, and Pittsburgh, PA, who were from the Health, Aging, and Body Composition study. Subjects' literacy was assessed with the Rapid Estimate of Adult Literacy in Medicine. Scores were categorized into limited (0 to 8th grade reading level) or adequate literacy (>= 9th grade reading level). Participants: Two thousand five hundred and twelve black and white elders without baseline functional difficulties or dementia. Measurements: Time to death. Results: Participants' mean age was 75.6 years, 48% were male, 38% were black, and 24% had limited literacy; the median follow-up time was 4.2 years. Compared with those with adequate literacy, those with limited literacy had a higher risk of death (19.7% vs 10.6%) with a hazard ratio (HR) of 2.03 (95% confidence intervals [CI], 1.62 to 2.55). After adjusting for demographics and socioeconomic status, co-morbid conditions, self-rated health status, health-related behaviors, health care access measures, and psychosocial status, limited literacy remained independently associated with mortality (HR 1.75; 95% CI, 1.27 to 2.41). Conclusions: Limited literacy is independently associated with a nearly 2-fold increase in mortality in the elderly. Given the growth of the aging population and the prevalence of chronic diseases, the mechanisms by which limited literacy is associated with mortality in the elderly warrant further investigation.