摘要：Objectives. This study analyzed whether inadequate functional health literacy is an independent risk factor for hospital admission. Methods. We studied a prospective cohort of 3260 Medicare managed care enrollees. Results. Of the participants, 29.5% were hospitalized. The crude relative risk (RR) of hospitalization was higher for individuals with inadequate literacy (n = 800; RR = 1.43; 95% confidence interval [CI] = 1.24, 1.65) and marginal literacy (n = 366; RR = 1.33; 95% CI = 1.09, 1.61) than for those with adequate literacy (n = 2094). In multivariate analysis, the adjusted relative risk of hospital admission was 1.29 (95% CI = 1.07, 1.55) for individuals with inadequate literacy and 1.21 (95% CI = 0.97, 1.50) for those with marginal literacy. Conclusions. Inadequate literacy was an independent risk factor for hospital admission among elderly managed care enrollees. (Am J Public Health. 2002;92:1278–1283) The National Adult Literacy Survey reported in 1993 that more than 40 million Americans were functionally illiterate, meaning that they could not perform the basic reading tasks necessary to function fully in society. 1 Although the National Adult Literacy Survey did not include health-related items, these findings suggest that a large proportion of Americans are unable to read and comprehend essential information they are likely to encounter when they interact with the health care system. A study conducted at 2 public hospitals found that one third of the English-speaking patients were classified as having inadequate functional health literacy, indicating that they were unable to read and comprehend the most basic health-related materials. 2 Such individuals are likely to struggle to read and comprehend prescription bottles, appointment slips, self-care instructions, and health education brochures. Similarly, individuals with inadequate literacy who have chronic diseases are less likely to know the basic elements of how to care for their medical problems, even if they have gone to special classes to learn how to manage their conditions. 3, 4 Inadequate literacy is especially prevalent among the elderly, the population with the largest burden of chronic disease and the greatest health-related reading demands. In the National Adult Literacy Survey, 44% of the adults aged 65 and older were classified as functionally illiterate. 1 The lower reading ability among older adults is most likely the result of age-related declines in information processing, and it is not explained by their having less education, a higher prevalence of chronic diseases, worse physical or mental health, or dementia. 5 Many elderly persons have difficulty understanding basic health information. Among Medicare managed care enrollees aged 65 and older in 4 US cities, 34% had inadequate or marginal functional health literacy. 6 The discordance between what we expect of patients and what is required for them to function optimally in the health care setting may have important cost implications. Although Weiss et al. 7 found no relation between literacy and medical care costs for a random sample of Medicaid recipients in Arizona, Kuh and Stirling 8 found that the risk of hospitalization for diseases of the female genital system was more than twice as high for the least educated compared with the most educated women. Similarly, we reported previously that among patients at a public hospital in Atlanta, Ga, those with inadequate literacy had a 52% higher risk of hospital admission compared with those with adequate literacy, even after adjustment for age, socioeconomic markers, and self-reported health. 9 The patients in that study were uniformly poor, and most had limited access to ambulatory care providers. Thus, the generalizability of the study findings is not known. It is important to gain a more accurate understanding of the relation between literacy and health care costs. If inadequate literacy leads to worse health outcomes and higher health care costs, then an incentive exists for health care providers and payers to develop education programs to reach all patients, regardless of reading ability. To explore the relation between functional health literacy (the ability to read and understand health-related materials) and the risk of hospital admission, we conducted a prospective cohort study of 3260 new Medicare managed care enrollees in 4 US cities whose literacy was assessed with the short version of the Test of Functional Health Literacy in Adults. 10, 11
