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Literacy, Cognitive Function, and Health: Results of the LitCog Study

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ABSTRACT

BACKGROUND

Emerging evidence suggests the relationship between health literacy and health outcomes could be explained by cognitive abilities.

OBJECTIVE

To investigate to what degree cognitive skills explain associations between health literacy, performance on common health tasks, and functional health status.

DESIGN

Two face-to-face, structured interviews spaced a week apart with three health literacy assessments and a comprehensive cognitive battery measuring ‘fluid’ abilities necessary to learn and apply new information, and ‘crystallized’ abilities such as background knowledge.

SETTING

An academic general internal medicine practice and three federally qualified health centers in Chicago, Illinois.

PATIENTS

Eight hundred and eighty-two English-speaking adults ages 55 to 74.

MEASUREMENTS

Health literacy was measured using the Rapid Estimate of Adult Literacy in Medicine (REALM), Test of Functional Health Literacy in Adults (TOFHLA), and Newest Vital Sign (NVS). Performance on common health tasks were globally assessed and categorized as 1) comprehending print information, 2) recalling spoken information, 3) recalling multimedia information, 4) dosing and organizing medication, and 5) healthcare problem-solving.

RESULTS

Health literacy measures were strongly correlated with fluid and crystallized cognitive abilities (range: r = 0.57 to 0.77, all p < 0.001). Lower health literacy and weaker fluid and crystallized abilities were associated with poorer performance on healthcare tasks. In multivariable analyses, the association between health literacy and task performance was substantially reduced once fluid and crystallized cognitive abilities were entered into models (without cognitive abilities: β = −28.9, 95 % Confidence Interval (CI) -31.4 to −26.4, p; with cognitive abilities: β = −8.5, 95 % CI −10.9 to −6.0).

LIMITATIONS

Cross-sectional analyses, English-speaking, older adults only.

CONCLUSIONS

The most common measures used in health literacy studies are detecting individual differences in cognitive abilities, which may predict one’s capacity to engage in self-care and achieve desirable health outcomes. Future interventions should respond to all of the cognitive demands patients face in managing health, beyond reading and numeracy.

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References

  1. Institute of Medicine. Health literacy: A prescription to end confusion: National Academy Press; 2004.

  2. DeWalt DA, Berkman ND, Sheridan S, Lohr KN, Pignone MP. Literacy and health outcomes. J Gen Intern Med. 2004;19:1228–39.

    Article  PubMed  Google Scholar 

  3. Wolf MS, Gazmararian JA, Baker DW. Health literacy and functional health status among older adults. Arch Intern Med. 2005;165:1946–52.

    Article  PubMed  Google Scholar 

  4. Baker DW, Parker RM, Williams MV, Clark WS. Health literacy and the risk of hospital admission. J Gen Intern Med. 1998;13:791–8.

    Article  PubMed  CAS  Google Scholar 

  5. Baker DW, Wolf MS, Feinglass J, Thompson JA, Gazmararian JA, Huang J. Health literacy and mortality among elderly persons. Arch Intern Med. 2007;167:1503.

    Article  PubMed  Google Scholar 

  6. Sudore RL, Yaffe K, Satterfield S, et al. Limited literacy and mortality in the elderly: the health, aging, and body composition study. J Gen Intern Med. 2006;21:806–12.

    Article  PubMed  Google Scholar 

  7. Gerber BS, Brodsky IG, Lawless KA, Smolin LI, Arozullah AM, Smith EV, Berbaum ML, Heckerling PS, Eiser AR. Implementation and evaluation of a low-literacy diabetes education computer multimedia application. Diabetes Care. 2005;28:1574–80.

    Article  PubMed  Google Scholar 

  8. Davis TC. Fredrickson DD. Arnold C. Murphy PW. Herbst M. Bocchini JA. A polio immunization pamphlet with increased appeal and simplified language does not improve comprehension to an acceptable level. Pat Ed Couns. 1998;35:25–3.

    Article  Google Scholar 

  9. Rothman RL, DeWalt DA, Malone R, Bryant B, Shintani A, Crigler B, Weinberger M, Pignone M. Influence of patient literacy on the effectiveness of a primary care-based diabetes disease management program. JAMA. 2004;292:1711–6.

    Article  PubMed  CAS  Google Scholar 

  10. Pignone M, DeWalt DA, Sheridan S, Berkman N, Lohr KN. Interventions to improve health outcomes for patients with low literacy. a systematic review. J Gen Intern Med. 2005;20:185–92

    Article  PubMed  Google Scholar 

  11. Clement S, Ibrahim S, Wolf MS, Rowlands G. Health literacy and complex interventions: A systematic literature review. Pat Educ Counsel. 2009;75:340–51.

    Article  Google Scholar 

  12. Wolf MS, Wilson EA, Rapp DN, Waite KR, Bocchini MV, Davis TC, Rudd RE. Literacy and Learning in Healthcare. Pediatrics. 2009;124:275–81.

    Article  Google Scholar 

  13. Deary IJ, Batty D, Gottfredson LS. Human hierarchies, health, and IQ. Science. 2005;309(5735):703.

    Article  PubMed  CAS  Google Scholar 

  14. Whalley LJ, Deary IJ. Longitudinal cohort study of childhood IQ and survival up to age 76. BMJ. 2001;322(7290):819.

    Article  PubMed  CAS  Google Scholar 

  15. Deary IJ, Whiteman MC, Starr JM, Whalley LJ, Fox HC. The impact of childhood intelligence on later life: following up the Scottish mental surveys of 1932 and 1947. J Pers Soc Psychol. 2004;86:130–47.

    Article  PubMed  Google Scholar 

  16. Murray C, Johnson W, Wolf MS, Deary IC. The association between cognitive ability across the lifespan and health literacy in old age: the Lothian Birth Cohort 1936. Intelligence 2011;39:178–187.

    Google Scholar 

  17. Singh-Manoux A, Ferrie JE, Lynch JW, Marmot M. The role of cognitive ability (intelligence) in explaining the association between socioeconomic position and health: evidence from the Whitehall II prospective cohort study. Am J Epidemiol. 2005;161:831–9.

    Article  PubMed  Google Scholar 

  18. Insel K, Morrow D, Brewer B, Figueredo A. Executive function, working memory, and medication adherence among older adults. J Gerontol B: Psychol Sci Soc Sci. 2006;61:102–7.

    Article  Google Scholar 

  19. Stilley CS, Sereika S, Muldoon MF, Ryan CM, Dunbar-Jacob J. Psychological and cognitive function: predictors of adherence with cholesterol lowering treatment. Ann Behav Med. 2004;27:117–24.

    Article  PubMed  Google Scholar 

  20. Shen BJ, McCreary CP, Myers HF. Independent and mediated contributions of personality, coping, social support, and depressive symptoms to physical functioning outcome among patients in cardiac rehabilitation. J Behav Med. 2004;27:39–62.

    Article  PubMed  Google Scholar 

  21. Batty GD, Mortensen EL, Nybo Andersen AM, Osler M. Childhood intelligence in relation to adult coronary heart disease and stroke risk: evidence from a Danish birth cohort study. Paediatr Perinat Epidemiol. 2005;19:452–9.

    Article  PubMed  Google Scholar 

  22. Shipley BA, Der G, Taylor MD, Deary IJ. Cognition and all-cause mortality across the entire adult age range: health and lifestyle survey. Psychosom Med. 2006;68:17–24.

    Article  PubMed  Google Scholar 

  23. Shaywitz SE, Shaywitz BA. Dyslexia (specific reading disability). Biol Psychiatry. 2005;57:1301–9.

    Article  PubMed  Google Scholar 

  24. Levinthal BR, Morrow DG, Tu W, Wu J, Murray MD. Cognition and health literacy in patients with hypertension. J Gen Intern Med. 2008;24:1172–6.

    Article  Google Scholar 

  25. Baker DW, Wolf MS, Feinglass J, Thompson JA. Health literacy, Cognitive Abilities, and Mortality among Elderly Persons. J Gen Intern Med. 2008;23:723–6.

    Article  PubMed  Google Scholar 

  26. Federman AD, Sano M, Safran DG, Siu AL, Wolf MS, Halm EA. Health literacy and cognitive performance among older adults. J Amer Ger Soc. 2009;57:1475–80.

    Article  Google Scholar 

  27. Wolf MS, Wilson EA, Rapp DN, Waite KR, Bocchini MV, Davis TC, Rudd RE. Literacy and Learning in Healthcare. Pediatrics. 2009;124:275–81.

    Article  Google Scholar 

  28. Wilson EA and Wolf MS. Working memory capacity and the design of patient education materials. Pat Educ Counsel. 2009;74:318–22.

    Article  Google Scholar 

  29. Parker RM, Baker DW, Williams MV, Nurss JR. The test of functional health literacy in adults: a new instrument for measuring patients' literacy skills. J Gen Intern Med. 1995;10:537–41.

    Article  PubMed  CAS  Google Scholar 

  30. Davis TC, Long SW, Jackson RH, et al. Rapid estimate of adult literacy in medicine: a shortened screening instrument. Fam Med. 1993;25:391.

    PubMed  CAS  Google Scholar 

  31. Weiss BD, Mays MZ, Martz W, et al. Quick assessment of literacy in primary care: the newest vital sign. Ann Fam Med. 2005;3:514.

    Article  PubMed  Google Scholar 

  32. American Association for Public Opinion Research. Standard definitions: Final dispositions of case codes and outcome rates for surveys. 3rd edition. Lenexa, Kansas: AAPOR; 2004.

    Google Scholar 

  33. Salthouse TA. What do adult age differences in the Digit Symbol Substitution Test reflect? J Gerontol: Psychol Sci. 1992;47:121–8.

    Google Scholar 

  34. Salthouse TA, Babcock RL. Decomposing adult age differences in working memory. Dev Psychol. 1991;27:763–76.

    Article  Google Scholar 

  35. Smith A. Symbol digit modalities test. Los Angeles: Western Psychological Services. 1991.

    Google Scholar 

  36. Robbins TW, James M, Owen AM, Sahakian BJ, McInnes L, Rabbitt PMA. Cambridge Neuropsychological Test Automated Battery (CANTAB): A Factor Analytic Study of a Large Sample of Normal Elderly Volunteers. Dement. 1994;5:266–81.

    PubMed  CAS  Google Scholar 

  37. Cherry KE, Park DC. Individual difference and contextual variables influence spatial memory in younger and older adults. Psychol Aging. 1993;8:517–7.

    Article  PubMed  CAS  Google Scholar 

  38. Ekstrom RB, French JW, Harman HH. ETS Kit of Factor-Referenced Cognitive Tests. Princeton, NJ: Educational Testing Service; 1976.

    Google Scholar 

  39. Raven JC. Standard progressive matrices: sets A, B, C, D and E. San Antonio, TX: Harcourt Assessment; 1976.

    Google Scholar 

  40. Grober E, Sliwinsk M, Korey SR. Development and validation of a model for estimating premorbid verbal intelligence in the elderly. J clin exp neuropsychol. 1991;13(6):933–49.

    Article  PubMed  CAS  Google Scholar 

  41. Zachary RA. Shipley Institute of Living Scale, Revised Manual. Los Angeles, CA: Western Psychological Services, 1986; 1986.

  42. Kluger A, Ferris SH, Golomb J, Mittelman MS, Reisberg B. Neuropsychological prediction of decline to dementia in nondemented elderly. J geriatr psychiatry neurol. 1999;12:168.

    Article  PubMed  CAS  Google Scholar 

  43. Institute of Medicine. Measures of Health Literacy. Workshop Summary, Washington D.C., National Academies Press: 2009.

    Google Scholar 

  44. Curtis LM, Revelle W, Wilson EAH, Waite KR, Park DC, Baker DW, Wolf MS. Assessment of everyday health tasks for older adults. Under revision. J Health Comm. 2010.

    Google Scholar 

  45. Willis SL, Jay GM, Diehl M, Marsiske M. Longitudinal change and prediction of everyday task competence in the elderly. Res aging. Vol 141992:68

  46. Kutner M, Greenberg E, Jin Y, Paulsen C. The Health Literacy of America’s Adults: Results from the 2003 National Assessment of Adult Literacy (NCES 2006–483). U.S. Department of Education. Washington, DC: National Center for Education Statistics; 2006.

    Google Scholar 

  47. Kirsch I, Jungeblut A, Jenkins L, Kolstad A. Adult Literacy in America: a first look at the findings of the National Adult Literacy Survey. U.S. Department of Education; 1993.

  48. McDonald RP. Test theory: A unified treatment. Mahwah, N.J.: L. Erlbaum Associates; 1999

    Google Scholar 

  49. Revelle W, Zinbarg RE. Coefficients alpha, beta, omega and the glb: comments on Sijtsma. Psychometrika. 2009;74:145–154.

    Article  Google Scholar 

  50. Vuong, QH. Likelihood ratio tests for model selection and non-nested hypotheses. Econometrica. 1989;57:307–33.

    Article  Google Scholar 

  51. U.S. Department of Health and Human Services. Healthy People 2020. http//www.healthypeople.gov. Accessed April 6, 2012.

  52. Kickbusch I and Maag D. Health Literacy. In: Heggenhougen K. and Quah S. (eds.): International Encyclopedia of Public Health, Vol 3. San Diego: Academic Press; 2008. pp. 204–11.

    Chapter  Google Scholar 

  53. Paasche-Orlow MK, Wolf MS. Evidence does not support clinical screening of literacy. J Gen Intern Med. 2008;23:100–2.

    Article  PubMed  Google Scholar 

  54. Johnson K, Weiss BD. How long does it take to assess literacy skills in clinical practice? JAFBM. 2008;21:211–4.

    Google Scholar 

  55. Ryan JG, Leguen F, Weiss BD, Albury A, Jennings T, Velez F, Salibi N. Will patients agree to have their literacy skills assessed in clinical practice? Health Ed Res. 2008;23:603–11

    Article  Google Scholar 

  56. Nutbeam D. The evolving concept of health literacy. Soc Sci Med. 2008;67:2072–8

    Article  PubMed  Google Scholar 

  57. Davis TC, Wolf MS, Davis TC, Bass PF, Tilson H, Neuberger M, Parker RM. Literacy and misunderstanding of prescription drug labels. Ann Intern Med. 2006;145:887–94.

    PubMed  Google Scholar 

  58. Rothman R, Housman T, Weiss H, et al. Patient understanding of food labels: the role of literacy and numeracy. Am J Prev Med. 2006;31:391–8.

    Article  PubMed  Google Scholar 

  59. Czaja SJ, Sharit J, Narit SN. Usability of the Medicare health web site. JAMA. 2008;300:790–2.

    Google Scholar 

  60. Baker DW, Gazmararian JA, Sudano J, Patterson M, Parker RM, Williams MV. Health literacy and performance on the Mini-Mental State Examination. Aging Ment Health. 2002;6:22–9.

    Article  PubMed  CAS  Google Scholar 

  61. Isham G. Opportunity at the Intersection of Quality Improvement, Disparities Reduction, and Health Literacy, Toward Health Care Equity and Patient-Centeredness. Institute of Medicine Workshop Summary; 2009.

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Acknowledgements

We would like to thank Elizabeth Bojarski, Rachel O’Conor, Emily Ross, and Rina Sobel for their determination and effort in recruiting and collecting data for the LitCog Study. This project was supported by the National Institute on Aging (R01 AG030611; PI: Wolf)

Conflict of Interest

The authors declare that they do not have a conflict of interest.

Funding

This project was supported by the National Institute on Aging (R01 AG030611; PI: Wolf)

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Correspondence to Michael S. Wolf PhD MPH.

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Wolf, M.S., Curtis, L.M., Wilson, E.A.H. et al. Literacy, Cognitive Function, and Health: Results of the LitCog Study. J GEN INTERN MED 27, 1300–1307 (2012). https://doi.org/10.1007/s11606-012-2079-4

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  • DOI: https://doi.org/10.1007/s11606-012-2079-4

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