Abstract
Background: Three validated functional health literacy tests (FHLTs) have been developed for use in healthcare settings. However, none of these tests has been shown to be readily applicable for use in the general public.
Objective: To develop and validate an FHLT for screening the functional health literacy level of the general public and patients in healthcare settings.
Methods: Maze procedure, expert judgment, and interviews with 55 respondents were used to develop the 21-item FHLT, which was modified from public health education material entitled Guidelines on Taking Medicines published by the Singapore Health Promotion Board. The finalized FHLT was then distributed by convenience sampling among eligible English-speaking respondents from the general public and rheumatic patients in Singapore. Descriptive analysis was used to summarize the sociodemographic characteristics and health status of the respondents. Cronbach’s α was used to assess the reliability of the test. Partial correlation coefficients were used to investigate the convergent validity between scores on the FHLT and the Rapid Estimate of Adult Literacy in Medicine (REALM), and the divergent validity between the FHLT score and education level. Test-retest reliability was assessed by intraclass correlation coefficient (ICC).
Results: Data were analyzed from 223 respondents from the general public (mean [SD] age: 43.8 [14.2] years, 49.3% female, 45.7% with >12 years of education) and 200 rheumatic patients (mean [SD] age: 46.6 [14.7], 70.5% female, 45.5% with >12 years of education). Cronbach’s α for the FHLT was 0.72 and 0.68 for the general public and rheumatic patients, respectively, suggesting adequate reliability. Convergent validity was demonstrated with a strong correlation between scores on the FHLT and REALM (0.65 [p<0.01] for the general public, 0.68 [p<0.01] for rheumatic patients). Divergent validity was shown by the weak correlation between the FHLT score and education level (0.33 [p<0.01] for the general public, 0.28 [p<0.01] for rheumatic patients). Test-retest reliability of the FHLT among rheumatic patients (n = 112, response rate = 56%) was shown to be high (ICC = 0.95). ICC was not calculated for the test-retest reliability among the general public because of a poor response rate of 9%.
Conclusions: The 21-item FHLT has been shown to be a reliable and valid screening test for measuring functional health literacy levels of the general public as well as patients in healthcare settings. The availability of the FHLT would contribute to the effectiveness of health education programs and better health-related outcomes in the general population.
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References
Andrus MR, Roth MT. Health literacy: a review. Pharmacotherapy 2002; 22(3): 282–302
Parker RM, Baker DW, Williams MV, et al. The test of functional health literacy in adults: a new instrument for measuring patients’ literacy skills. J Gen Intern Med 1995; 10: 537–41
Baker DW. Reading between the lines: deciphering the connections between literacy and health. J Gen Intern Med 1995; 14: 315–7
Speros C. Health literacy: concept analysis. J Adv Nurs 2005; 50(6): 633–40
Morrow D, Clark D, Tu W, et al. Correlates of health literacy in patients with chronic heart failure. Gerontologist 2006; 46(5): 669–76
Rutherford J, Holman R, MacDonald J, et al. Low literacy: a hidden problem in family planning clinics. J Fam Plann Reprod Health Care 2006; 32(4): 235–40
Schillinger D, Barton LR, Karter AJ, et al. Does literacy mediate the relationship between education and health outcomes? A study of a low-income population with diabetes. Public Health Rep 2006; 121(3): 245–54
Guerra CE, Dominguez F, Shea JA. Literacy and knowledge, attitudes, and behavior about colorectal cancer screening. J Health Commun 2005; 10(7): 651–63
Howard DH, Gazmararian J, Parker RM. The impact of low health literacy on the medical costs of Medicare managed care enrollees. Am J Med 2005; 118(4): 371–7
Weiss BD. Health literacy: an important issue for communicating health information to patients. Zhonghua Yi Xue Za Zhi (Taipei) 2001; 64(11): 603–8
Kleinpeter MA. Health literacy affects peritoneal dialysis performance and outcomes. Adv Perit Dial 2003; 19: 115–9
Weiss BD, Mays MZ, Martz W, et al. Quick assessment of literacy in primary care: the Newest Vital Sign. Ann Fam Med 2005; 3(6): 514–22
Gong DA, Lee JY, Rozier RG, et al. Development and testing of the Test Of Functional Health Literacy in Dentistry (TOFHLiD). J Public Health Dent 2007; 67(2): 105–12
Parker RM, Baker DW, Williams MV, et al. The test of functional health literacy in adults: a new instrument for measuring patients’ literacy skills. J Gen Intern Med 1995; 10(10): 537–41
King DK. Reaction and questions for discussion re: the NVS health literacy assessment. Ann Fam Med 2005 Dec 9 [online]. Available from URL: http://www.annfammed.org/cgi/eletters/3/6/514 [Accessed 2009 Jun 19]
Bennet IM. Some questions about screening for literacy. Ann Fam Med 2005 Dec 12 [online]. Available from URL: http://www.annfammed.org/cgi/eletters/3/6/514 [Accessed 2009 Jun 18]
Baker DW, Williams MV, Parker RM, et al. Development of a brief test to measure functional health literacy. Patient Educ Couns 1999; 38(1): 33–42
DeWalt DA, Pignone MP. Reading is fundamental: the relationship between literacy and health. Arch Intern Med 2005; 165: 1943–4
Cheah J. Chronic disease management: a Singapore perspective. BMJ 2001; 323(7319): 990–3
Davis TC, Wolf MS. Health literacy: implications for family medicine. Fam Med 2004 Sep; 36(8): 595–8
Eysenbach G, Powell J, Kuss O, et al. Empirical studies assessing the quality of health information for consumers on the world wide web: a systematic review. JAMA 2002; 287(20): 2691–700
National Center for Education Statistics. National adult literacy survey [online]. Available from URL: http://www.nces.ed.gov/pubsearch/pubsinfo.asp?pubid=93275 [Accessed 2007 Mar 6]
Aldridge MD. Writing and designing readable patient education materials. Nephrol Nurs J 2004; 31(4): 373–7
Davis TC, Crouch MA, Long SW, et al. Rapid assessment of literacy levels of adult primary care patients. Fam Med 1991; 23(6): 433–5
Rye J. Cloze procedures and the teaching of reading. London: Heinemann Educational, 1982
Health Promotion Board, Singapore. Guidelines on taking medicines [online]. Available from URL: http://www.hpb.gov.sg/hpb/ere/ere0307.asp?id=24110 [Accessed 2007 Mar 6]
Rabin R, Charro F. EQ-5D: a measure of health status from the EuroQol Group. Ann Med 2001; 33: 337–43
Dolan P. Modeling valuations for EuroQol health states. Med Care 1997; 35: 1095–108
Luo N, Chew LH, Fong KY, et al. Validity and reliability of the EQ-5D self-report questionnaire in English-speaking Asian patients with rheumatic diseases in Singapore. Qual Life Res 2003; 12(1): 87–92
Cronbach LJ. Coefficient alpha and the internal structure of tests. Psychometrika 1951; 22: 293–6
Guyatt G, King D, Stubbing FD, et al. Generic and specific measurement of health-related quality of life in a clinical trial of respiratory rehabilitation. J Clin Epidemiol 1999; 52: 187–92
Aiken LR. Psychological testing and assessment. Boston (MA): Allyn and Bacon, 1997
Slosson RJL. Slosson oral reading tests — revised. East Aurora (NY): Slosson Educational Publishers, 1990
Miller DP, Brownlee CD, McCoy TP, et al. The effect of health literacy on knowledge and receipt of colorectal cancer screening: a survey study. BMC Fam Pract 2007 Mar 30; 8: 16 [online]. Available from URL: http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1852801 [Accessed 2009 Jun 18]
Dowse R, Ehlers M. Medicine labels incorporating pictograms: do they influence understanding and adherence? Patient Educ Couns 2005; 58(1): 63–70
Kleinbeck C. Reaching positive diabetes outcomes for patients with low literacy. Home Healthc Nurse 2005; 23(1): 16–22
Hoffmann T, Worrall L. Designing effective written health education materials: considerations for health professionals. Disabil Rehabil 2004; 26(19): 1166–73
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No sources of funding were used to assist in the preparation of this study. The authors have no conflicts of interest that are directly relevant to the content of this study.
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Zhang, XH., Thumboo, J., Fong, KY. et al. Development and Validation of a Functional Health Literacy Test. Patient-Patient-Centered-Outcome-Res 2, 169–178 (2009). https://doi.org/10.2165/11314850-000000000-00000
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DOI: https://doi.org/10.2165/11314850-000000000-00000