Literacy and blood pressure--do healthcare systems influence this relationship? A cross-sectional study

Benjamin J Powers, Maren K Olsen, Eugene Z Oddone, Carolyn T Thorpe, Hayden B Bosworth, Benjamin J Powers, Maren K Olsen, Eugene Z Oddone, Carolyn T Thorpe, Hayden B Bosworth

Abstract

Background: Limited literacy is common among patients with chronic conditions and is associated with poor health outcomes. We sought to determine the association between literacy and blood pressure in primary care patients with hypertension and to determine if this relationship was consistent across distinct systems of healthcare delivery.

Methods: We conducted a cross-sectional study of 1224 patients with hypertension utilizing baseline data from two separate, but similar randomized controlled trials. Patients were enrolled from primary care clinics in the Veterans Affairs healthcare system (VAHS) and a university healthcare system (UHS) in Durham, North Carolina. We compared the association between literacy and the primary outcome systolic blood pressure (SBP) and secondary outcomes of diastolic blood pressure (DBP) and blood pressure (BP) control across the two different healthcare systems.

Results: Patients who read below a 9th grade level comprised 38.4% of patients in the VAHS and 27.5% of the patients in the UHS. There was a significant interaction between literacy and healthcare system for SBP. In adjusted analyses, SBP for patients with limited literacy was 1.2 mmHg lower than patients with adequate literacy in the VAHS (95% CI, -4.8 to 2.3), but 6.1 mmHg higher than patients with adequate literacy in the UHS (95% CI, 2.1 to 10.1); (p = 0.003 for test of interaction). This literacy by healthcare system interaction was not statistically significant for DBP or BP control.

Conclusion: The relationship between patient literacy and systolic blood pressure varied significantly across different models of healthcare delivery. The attributes of the healthcare delivery system may influence the relationship between literacy and health outcomes.

Figures

Figure 1
Figure 1
Adjusted systolic blood pressure by healthcare system and literacy. Adjusted for variables in model listed on Table 2. Error bars represent 95% confidence intervals. P value from test of interaction between literacy and healthcare system = 0.003.

References

    1. Nielsen-Bohlman L, Institute of Medicine (U.S.). Committee on Health Literacy . Health literacy: a prescription to end confusion. Washington, D.C.: National Academies Press; 2004.
    1. National Assessment of Adult Literacy. 2003.
    1. Williams MV, Parker RM, Baker DW, Parikh NS, Pitkin K, Coates WC, Nurss JR. Inadequate functional health literacy among patients at two public hospitals. JAMA. 1995;274:1677–1682. doi: 10.1001/jama.274.21.1677.
    1. Gazmararian JA, Baker DW, Williams MV, Parker RM, Scott TL, Green DC, Fehrenbach SN, Ren J, Koplan JP. Health literacy among Medicare enrollees in a managed care organization. JAMA. 1999;281:545–551. doi: 10.1001/jama.281.6.545.
    1. Wilson JF. The crucial link between literacy and health. Ann Intern Med. 2003;139:875–878.
    1. Dewalt DA, Berkman ND, Sheridan S, Lohr KN, Pignone MP. Literacy and health outcomes: a systematic review of the literature. J Gen Intern Med. 2004;19:1228–1239. doi: 10.1111/j.1525-1497.2004.40153.x.
    1. Wolf MS, Gazmararian JA, Baker DW. Health literacy and functional health status among older adults. Arch Intern Med. 2005;165:1946–1952. doi: 10.1001/archinte.165.17.1946.
    1. Sudore RL, Yaffe K, Satterfield S, Harris TB, Mehta KM, Simonsick EM, Newman AB, Rosano C, Rooks R, Rubin SM, Ayonayon HN, Schillinger D. Limited literacy and mortality in the elderly: the health, aging, and body composition study. J Gen Intern Med. 2006;21:806–812. doi: 10.1111/j.1525-1497.2006.00539.x.
    1. Carmona RH. Health Literacy: A National Priority. J Gen Intern Med. 2006;21:803–803. doi: 10.1111/j.1525-1497.2006.00569.x.
    1. Health literacy: report of the Council on Scientific Affairs. Ad Hoc Committee on Health Literacy for the Council on Scientific Affairs, American Medical Association. JAMA. 1999;281:552–557. doi: 10.1001/jama.281.6.552.
    1. Fields LE, Burt VL, Cutler JA, Hughes J, Roccella EJ, Sorlie P. The burden of adult hypertension in the United States 1999 to 2000: a rising tide. Hypertension. 2004;44:398–404. doi: 10.1161/01.HYP.0000142248.54761.56.
    1. Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL, Jones DW, Materson BJ, Oparil S, Wright JT, Roccella EJ. The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC 7 report. JAMA. 2003;289:2560–2572. doi: 10.1001/jama.289.19.2560.
    1. Neal B, MacMahon S, Chapman N. Effects of ACE inhibitors, calcium antagonists, and other blood-pressure-lowering drugs: results of prospectively designed overviews of randomised trials. Blood Pressure Lowering Treatment Trialists' Collaboration. Lancet. 2000;356:1955–1964. doi: 10.1016/S0140-6736(00)03307-9.
    1. Ogden LG, He J, Lydick E, Whelton PK. Long-term absolute benefit of lowering blood pressure in hypertensive patients according to the JNC VI risk stratification. Hypertension. 2000;35:539–543.
    1. Healthy People 2010. US Dept of Health and Human Services: Government Printing Office; 2000.
    1. Williams MV, Baker DW, Parker RM, Nurss JR. Relationship of functional health literacy to patients' knowledge of their chronic disease. A study of patients with hypertension and diabetes. Arch Intern Med. 1998;158:166–172. doi: 10.1001/archinte.158.2.166.
    1. 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;292:1711–1716. doi: 10.1001/jama.292.14.1711.
    1. DeWalt D, Malone R, Bryant M, Kosnar M, Corr K, Rothman R, Sueta C, Pignone M. A heart failure self-management program for patients of all literacy levels: A randomized, controlled trial [ISRCTN11535170] BMC Health Serv Research. 2006;6:30. doi: 10.1186/1472-6963-6-30.
    1. Copayments for medications. Final rule. Fed Regist. 2001;66:63449–63451.
    1. Bosworth HB, Olsen MK, Goldstein MK, Orr M, Dudley T, McCant F, Gentry P, Oddone EZ. The veterans' study to improve the control of hypertension (V-STITCH): design and methodology. Contemp Clin Trials. 2005;26:155–168. doi: 10.1016/j.cct.2004.12.006.
    1. Bosworth HB, Olsen MK, Dudley T, Orr M, Neary A, Harrelson M, Adams M, Svetkey LP, Dolor RJ, Oddone EZ. The Take Control of Your Blood pressure (TCYB) study: study design and methodology. Contemp Clin Trials. 2007;28:33–47. doi: 10.1016/j.cct.2006.08.006.
    1. The Sixth Report of the Joint National Committee on prevention, detection, evaluation, and treatment of high blood pressure. Arch Intern Med. 1997;157:2413–46. doi: 10.1001/archinte.157.21.2413.
    1. Davis TC, Long SW, Jackson RH, Mayeaux EJ, George RB, Murphy PW, Crouch MA. Rapid estimate of adult literacy in medicine: a shortened screening instrument. Family Medicine. 1993;25:391–395.
    1. 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;10:537–541. doi: 10.1007/BF02640361.
    1. Baker DW, Williams MV, Parker RM, Gazmararian JA, Nurss J. Development of a brief test to measure functional health literacy. Patient Educ Couns. 1999;38:33–42. doi: 10.1016/S0738-3991(98)00116-5.
    1. Bosworth HB, Bastian LA, Kuchibhatla MN, Steffens DC, McBride CM, Skinner CS, Rimer BK, Siegler IC. Depressive symptoms, menopausal status, and climacteric symptoms in women at midlife. Psychosom Med. 2001;63:603–608.
    1. Morisky DE, Green LW, Levine DM. Concurrent and predictive validity of a self-reported measure of medication adherence. Med Care. 1986;24:67–74. doi: 10.1097/00005650-198601000-00007.
    1. Lowry KP, Dudley TK, Oddone EZ, Bosworth HB. Intentional and unintentional nonadherence to antihypertensive medication. Ann Pharmacotherapy. 2005;39:1198–1203. doi: 10.1345/aph.1E594.
    1. Kaplan SH, Gandek B, Greenfield S, Rogers W, Ware JE. Patient and visit characteristics related to physicians' participatory decision-making style. Results from the Medical Outcomes Study. Med Care. 1995;33:1176–1187. doi: 10.1097/00005650-199512000-00002.
    1. Lewington S, Clarke R, Qizilbash N, Peto R, Collins R. Age-specific relevance of usual blood pressure to vascular mortality: a meta-analysis of individual data for one million adults in 61 prospective studies. Lancet. 2002;360:1903–1913. doi: 10.1016/S0140-6736(02)11911-8.
    1. Paasche-Orlow M, Schillinger D, Greene S, Wagner E. How health care systems can begin to address the challenge of limited literacy. J Gen Intern Med. 2006;21:884–887. doi: 10.1111/j.1525-1497.2006.00544.x.
    1. Wagner EH, Austin BT, Davis C, Hindermarsh M, Schaefer J, Bonomi A. Improving chronic illness care: translating evidence into action. Health Affairs (Millwood) 2001;20:64–78. doi: 10.1377/hlthaff.20.6.64.

Source: PubMed

Sponsoren und Mitarbeiter

Krankheiten

Drogeninterventionen

3
Abonnieren