Kerri L. Cavanaugh

Low Health Literacy Associates with Increased Mortality in ESRD

Limited health literacy is common in the United States and associates with poor clinical outcomes. Little is known about the effect of health literacy in patients with advanced kidney disease. In this prospective cohort study we describe the prevalence of limited health literacy and examine its association with the risk for mortality in hemodialysis patients. We enrolled 480 incident chronic hemodialysis patients from 77 dialysis clinics between 2005 and 2007 and followed them until April 2008. Measured using the Rapid Estimate of Adult Literacy in Medicine, 32% of patients had limited (<9th grade reading level) and 68% had adequate health literacy (≥9th grade reading level). Limited health literacy was more likely in patients who were male and non-white and who had fewer years of education. Compared with adequate literacy, limited health literacy associated with a higher risk for death (HR 1.54; 95% CI 1.01 to 2.36) even after adjustment for age, sex, race, and diabetes. In summary, limited health literacy is common and associates with higher mortality in chronic hemodialysis patients. Addressing health literacy may improve survival for these patients.

Addressing Literacy and Numeracy to Improve Diabetes Care: Two Randomized Controlled Trials

OBJECTIVE Diabetic patients with lower literacy or numeracy skills are at greater risk for poor diabetes outcomes. This study evaluated the impact of providing literacy- and numeracy-sensitive diabetes care within an enhanced diabetes care program on A1C and other diabetes outcomes. RESEARCH DESIGN AND METHODS In two randomized controlled trials, we enrolled 198 adult diabetic patients with most recent A1C ≥7.0%, referred for participation in an enhanced diabetes care program. For 3 months, control patients received care from existing enhanced diabetes care programs, whereas intervention patients received enhanced programs that also addressed literacy and numeracy at each institution. Intervention providers received health communication training and used the interactive Diabetes Literacy and Numeracy Education Toolkit with patients. A1C was measured at 3 and 6 months follow-up. Secondary outcomes included self-efficacy, self-management behaviors, and treatment satisfaction. RESULTS At 3 months, both intervention and control patients had significant improvements in A1C from baseline (intervention −1.50 [95% CI −1.80 to −1.02]; control −0.80 [−1.10 to −0.30]). In adjusted analysis, there was greater improvement in A1C in the intervention group than in the control group (P = 0.03). At 6 months, there were no differences in A1C between intervention and control groups. Self-efficacy improved from baseline for both groups. No significant differences were found for self-management behaviors or satisfaction. CONCLUSIONS A literacy- and numeracy-focused diabetes care program modestly improved self-efficacy and glycemic control compared with standard enhanced diabetes care, but the difference attenuated after conclusion of the intervention.

Health Literacy Explains Racial Disparities in Diabetes Medication Adherence

Although low health literacy and suboptimal medication adherence are more prevalent in racial/ethnic minority groups than Whites, little is known about the relationship between these factors in adults with diabetes, and whether health literacy or numeracy might explain racial/ethnic disparities in diabetes medication adherence. Previous work in HIV suggests health literacy mediates racial differences in adherence to antiretroviral treatment, but no study to date has explored numeracy as a mediator of the relationship between race/ethnicity and medication adherence. This study tested whether health literacy and/or numeracy were related to diabetes medication adherence, and whether either factor explained racial differences in adherence. Using path analytic models, we explored the predicted pathways between racial status, health literacy, diabetes-related numeracy, general numeracy, and adherence to diabetes medications. After adjustment for covariates, African American race was associated with poor medication adherence (r = −0.10, p < .05). Health literacy was associated with adherence (r = .12, p < .02), but diabetes-related numeracy and general numeracy were not related to adherence. Furthermore, health literacy reduced the effect of race on adherence to nonsignificance, such that African American race was no longer directly associated with lower medication adherence (r = −0.09, p = .14). Diabetes medication adherence promotion interventions should address patient health literacy limitations.

Self-Efficacy Links Health Literacy and Numeracy to Glycemic Control

The mechanisms underlying the relationship between health literacy, numeracy, and glycemic control are unclear. We explored the role of diabetes self-efficacy in the predicted pathway linking health literacy and numeracy to glycemic control (A1C). Adults with type 1 or type 2 diabetes mellitus (N = 383) were enrolled in a cross-sectional study at primary care and diabetes clinics at three medical centers. Data collected included demographic information, health literacy, general numeracy, and A1C. Path models estimated relations among health literacy, numeracy, and diabetes self-efficacy as predictors of A1C. Health literacy (r = 0.14, p < .01) and numeracy (r = 0.17, p < .001) were each associated with greater diabetes self-efficacy, and greater diabetes self-efficacy was associated with lower A1C levels (r = −0.25, p < .001). When considered in combination, numeracy was related to diabetes self-efficacy (r = 0.13, p < .05), and the effect of health literacy on diabetes self-efficacy was reduced to non-significance (r = 0.06, p = .30). Health literacy and numeracy are each associated with greater diabetes self-efficacy, and greater diabetes self-efficacy is associated with lower A1C levels. Diabetes self-efficacy may be an important target of interventions to improve diabetes control and promote health equity related to health literacy and general numeracy skills needed for diabetes management.

Development and validation of the Diabetes Numeracy Test (DNT)

BackgroundLow literacy and numeracy skills are common. Adequate numeracy skills are crucial in the management of diabetes. Diabetes patients use numeracy skills to interpret glucose meters, administer medications, follow dietary guidelines and other tasks. Existing literacy scales may not be adequate to assess numeracy skills. This paper describes the development and psychometric properties of the Diabetes Numeracy Test (DNT), the first scale to specifically measure numeracy skills used in diabetes.MethodsThe items of the DNT were developed by an expert panel and refined using cognitive response interviews with potential respondents. The final version of the DNT (43 items) and other relevant measures were administered to a convenience sample of 398 patients with diabetes. Internal reliability was determined by the Kuder-Richardson coefficient (KR-20). An a priori hypothetical model was developed to determine construct validity. A shortened 15-item version, the DNT15, was created through split sample analysis.ResultsThe DNT had excellent internal reliability (KR-20 = 0.95). The DNT was significantly correlated (p < 0.05) with education, income, literacy and math skills, and diabetes knowledge, supporting excellent construct validity. The mean score on the DNT was 61% and took an average of 33 minutes to complete. The DNT15 also had good internal reliability (KR-20 = 0.90 and 0.89). In split sample analysis, correlations of the DNT-15 with the full DNT in both sub-samples was high (rho = 0.96 and 0.97, respectively).ConclusionThe DNT is a reliable and valid measure of diabetes related numeracy skills. An equally adequate but more time-efficient version of the DNT, the DNT15, can be used for research and clinical purposes to evaluate diabetes related numeracy.

Diabetes Numeracy: An overlooked factor in understanding racial disparities in glycemic control

OBJECTIVE Understanding the reasons and eliminating the pervasive health disparities in diabetes is a major research, clinical, and health policy goal. We examined whether health literacy, general numeracy, and diabetes-related numeracy explain the association between African American race and poor glycemic control (A1C) in patients with diabetes. RESEARCH DESIGN AND METHODS Adults with type 2 diabetes (n = 383) were enrolled in a cross-sectional study at primary care and diabetes clinics at three medical centers. Data collected included the following: self-reported race, health literacy, general numeracy, diabetes-related numeracy, A1C, and sociodemographic factors. A series of structural equation models were estimated to explore the interrelations between variables and test for mediation. RESULTS In model 1, younger age (r = −0.21, P < 0.001), insulin use (r = 0.27, P < 0.001), greater years with diabetes (r = 0.16, P < 0.01), and African American race (r = 0.12, P < 0.01) were all associated with poorer glycemic control. In model 2, diabetes-related numeracy emerged as a strong predictor of A1C (r = −0.46, P < 0.001), reducing the association between African American and poor glycemic control to nonsignificance (r = 0.10, NS). In model 3, African American race and older age were associated with lower diabetes-related numeracy; younger age, insulin use, more years with diabetes, and lower diabetes-related numeracy were associated with poor glycemic control. CONCLUSIONS Diabetes-related numeracy reduced the explanatory power of African American race, such that low diabetes-related numeracy, not African American race, was significantly related to poor glycemic control. Interventions that address numeracy could help to reduce racial disparities in diabetes.

Literacy, numeracy, and portion-size estimation skills.

BACKGROUND Portion-size estimation is an important component of weight management. Literacy and numeracy skills may be important for accurate portion-size estimation. It was hypothesized that low literacy and numeracy would be associated with decreased accuracy in portion estimation. METHODS A cross-sectional study of primary care patients was performed from July 2006 to August 2007; analyses were performed from January 2008 to October 2008. Literacy and numeracy were assessed with validated measures (the Rapid Estimate of Adult Literacy in Medicine and the Wide Range Achievement Test, third edition). For three solid-food items and one liquid item, participants were asked to serve both a single serving and a specified weight or volume amount representing a single serving. Portion-size estimation was considered accurate if it fell within +/-25% of a single standard serving. RESULTS Of 164 participants, 71% were women, 64% were white, and mean (SD) BMI was 30.6 (8.3) kg/m(2). While 91% reported completing high school, 24% had <9th-grade literacy skills and 67% had <9th-grade numeracy skills. When all items were combined, 65% of participants were accurate when asked to serve a single serving, and 62% were accurate when asked to serve a specified amount. In unadjusted analyses, both literacy and numeracy were associated with inaccurate estimation. In multivariate analyses, only lower literacy was associated with inaccuracy in serving a single serving (OR=2.54; 95% CI=1.11, 5.81). CONCLUSIONS In this study, many participants had poor portion-size estimation skills. Lower literacy skills were associated with less accuracy when participants were asked to serve a single serving. Opportunities may exist to improve portion-size estimation by addressing literacy.

Low Numeracy Skills Are Associated With Higher BMI

Low numeracy skills and obesity are both common. Numeracy skills are used in healthy weight management to monitor caloric intake. The relationship between obesity and numeracy skills in adult primary care patients is unknown. A cross‐sectional study enrolled adult, English‐speaking primary care patients. BMI was assessed by self‐report; numeracy and literacy skills were measured with the Wide Range Achievement Test, 3rd Edition (WRAT‐3) and the Rapid Estimate of Adult Literacy in Medicine (REALM), respectively. The relationship between numeracy and BMI was described with Spearmans rank correlation and linear regression analyses. In 160 patients, the mean (s.d.) age was 46 (16) years, 66% were white, 70% were female, and 91% completed high school. The mean BMI was 30.5 (8.3) kg/m2. Less than 9th grade numeracy skills were found in 66% of the participants. Participants with numeracy skills <9th grade had a mean BMI of 31.8 (9.0) whereas those with numeracy skills ≥9th grade had a mean BMI of 27.9 (6.0), P = 0.008. Numeracy was negatively and significantly correlated with BMI (ρ = −0.26, P = 0.001). This correlation persisted after adjusting for age, sex, race, income, years of education, and literacy (β coefficient = −0.14; P = 0.010). Literacy skills were not associated with BMI. We found a significant association between low numeracy skills and higher BMI in adult primary care patients. A causal relationship cannot be determined. However, numeracy may have important clinical implications in the design and implementation of healthy weight management interventions and should be further evaluated to determine the magnitude of its effect.

The Diabetes Literacy and Numeracy Education Toolkit (DLNET) Materials to Facilitate Diabetes Education and Management in Patients With Low Literacy and Numeracy Skills

Purpose Diabetes self-management education is an important component of comprehensive diabetes care. Patients with low health literacy and numeracy may have difficulty translating information from traditional diabetes educational programs and materials into effective self-care. Methods To address this potential barrier to successful diabetes teaching and counseling, the authors developed the Diabetes Literacy and Numeracy Education Toolkit (DLNET). Conclusion The DLNET is composed of 24 interactive modules covering standard diabetes care topics that can be customized to individual patient needs and used by all members of the multidisciplinary diabetes care team. The materials content and formatting aims to improve the ease of use for diabetes patients with low literacy and numeracy by adhering to a lower text reading level, using illustrations for key concepts, and color-coding and other accommodations to guide patients through instructions for self-care. Individual sections of the DLNET may be provided to patients for initial teaching, as well as for reinforcement. Although designed for lower literacy and numeracy skills, the DLNET provides unique materials to facilitate diabetes education for all patients.

Associations among perceived and objective disease knowledge and satisfaction with physician communication in patients with chronic kidney disease

It is likely that patients with chronic kidney disease (CKD) have a limited understanding of their illness. Here we studied the relationships between objective and perceived knowledge in CKD using the Kidney Disease Knowledge Survey and the Perceived Kidney Disease Knowledge Survey. We quantified perceived and objective knowledge in 399 patients at all stages of non-dialysis-dependent CKD. Demographically, the patient median age was 58 years, 47% were women, 77% had stages 3-5 CKD, and 83% were Caucasians. The overall median score of the perceived knowledge survey was 2.56 (range: 1-4), and this new measure exhibited excellent reliability and construct validity. In unadjusted analysis, perceived knowledge was associated with patient characteristics defined a priori, including objective knowledge and patient satisfaction with physician communication. In adjusted analysis, older age, male gender, and limited health literacy were associated with lower perceived knowledge. Additional analysis revealed that perceived knowledge was associated with significantly higher odds (2.13), and objective knowledge with lower odds (0.91), of patient satisfaction with physician communication. Thus, our results present a mechanism to evaluate distinct forms of patient kidney knowledge and identify specific opportunities for education tailored to patients with CKD.