Tom A. Elasy

Comparative Effectiveness of Sulfonylurea and Metformin Monotherapy on Cardiovascular Events in Type 2 Diabetes Mellitus: A Cohort Study

BACKGROUND The effects of sulfonylureas and metformin on outcomes of cardiovascular disease (CVD) in type 2 diabetes are not well-characterized. OBJECTIVE To compare the effects of sulfonylureas and metformin on CVD outcomes (acute myocardial infarction and stroke) or death. DESIGN Retrospective cohort study. SETTING National Veterans Health Administration databases linked to Medicare files. PATIENTS Veterans who initiated metformin or sulfonylurea therapy for diabetes. Patients with chronic kidney disease or serious medical illness were excluded. MEASUREMENTS Composite outcome of hospitalization for acute myocardial infarction or stroke, or death, adjusted for baseline demographic characteristics; medications; cholesterol, hemoglobin A1c, and serum creatinine levels; blood pressure; body mass index; health care utilization; and comorbid conditions. RESULTS Among 253 690 patients initiating treatment (98 665 with sulfonylurea therapy and 155 025 with metformin therapy), crude rates of the composite outcome were 18.2 per 1000 person-years in sulfonylurea users and 10.4 per 1000 person-years in metformin users (adjusted incidence rate difference, 2.2 [95% CI, 1.4 to 3.0] more CVD events with sulfonylureas per 1000 person-years; adjusted hazard ratio [aHR], 1.21 [CI, 1.13 to 1.30]). Results were consistent for both glyburide (aHR, 1.26 [CI, 1.16 to 1.37]) and glipizide (aHR, 1.15 [CI, 1.06 to 1.26]) in subgroups by CVD history, age, body mass index, and albuminuria; in a propensity score-matched cohort analysis; and in sensitivity analyses. LIMITATION Most of the veterans in the study population were white men; data on women and minority groups were limited but reflective of the Veterans Health Administration population. CONCLUSION Use of sulfonylureas compared with metformin for initial treatment of diabetes was associated with an increased hazard of CVD events or death. PRIMARY FUNDING SOURCE Agency for Healthcare Research and Quality and the U.S. Department of Health and Human Services.

Diabetes patient education: a meta-analysis and meta-regression

Diabetes education has largely been accepted in diabetes care. The effect of diabetes education on glycemic control and the components of education responsible for such an effect are uncertain. We performed a meta-analysis of randomized controlled trials of diabetes patient education published between 1990 and December 2000 to quantitatively assess and characterize the effect of patient education on glycated hemoglobin (HbA(1c)). Additionally, we used meta-regression to analyze which variables within an education intervention that best explained variance in glycemic control. Twenty-eight educational interventions (n=2439) were included in the analysis. The net glycemic change was 0.320% lower in the intervention group than in the control group. Meta-regression revealed that interventions which included a face-to-face delivery, cognitive reframing teaching method, and exercise content were more likely to improve glycemic control. Those three areas collectively explained 44% of the variance in glycemic control. Current patient education interventions modestly improve glycemic control in adults with diabetes. We highlight three potential components of educational interventions that may predict an increased likelihood of success in ameliorating glycemic control.

The Relationship Between Body Mass Index and Self-Reported Functional Limitation Among Older Adults: A Gender Difference

OBJECTIVES: To determine whether there is a gender difference in how body mass index (BMI) relates to self‐reported functional limitation. Also, to evaluate whether the method of categorizing BMI changes the observed results.

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.

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.

Association Between Intensification of Metformin Treatment With Insulin vs Sulfonylureas and Cardiovascular Events and All-Cause Mortality Among Patients With Diabetes

IMPORTANCE Preferred second-line medication for diabetes treatment after metformin failure remains uncertain. OBJECTIVE To compare time to acute myocardial infarction (AMI), stroke, or death in a cohort of metformin initiators who added insulin or a sulfonylurea. DESIGN, SETTING, AND PARTICIPANTS Retrospective cohort constructed with national Veterans Health Administration, Medicare, and National Death Index databases. The study population comprised veterans initially treated with metformin from 2001 through 2008 who subsequently added either insulin or sulfonylurea. Propensity score matching on characteristics was performed, matching each participant who added insulin to 5 who added a sulfonylurea. Patients were followed through September 2011 for primary analyses or September 2009 for cause-of-death analyses. MAIN OUTCOMES AND MEASURES Risk of a composite outcome of AMI, stroke hospitalization, or all-cause death was compared between therapies with marginal structural Cox proportional hazard models adjusting for baseline and time-varying demographics, medications, cholesterol level, hemoglobin A1c level, creatinine level, blood pressure, body mass index, and comorbidities. RESULTS Among 178,341 metformin monotherapy patients, 2948 added insulin and 39,990 added a sulfonylurea. Propensity score matching yielded 2436 metformin + insulin and 12,180 metformin + sulfonylurea patients. At intensification, patients had received metformin for a median of 14 months (IQR, 5-30), and hemoglobin A1c level was 8.1% (IQR, 7.2%-9.9%). Median follow-up after intensification was 14 months (IQR, 6-29 months). There were 172 vs 634 events for the primary outcome among patients who added insulin vs sulfonylureas, respectively (42.7 vs 32.8 events per 1000 person-years; adjusted hazard ratio [aHR], 1.30; 95% CI, 1.07-1.58; P = .009). Acute myocardial infarction and stroke rates were statistically similar, 41 vs 229 events (10.2 and 11.9 events per 1000 person-years; aHR, 0.88; 95% CI, 0.59-1.30; P = .52), whereas all-cause death rates were 137 vs 444 events, respectively (33.7 and 22.7 events per 1000 person-years; aHR, 1.44; 95% CI, 1.15-1.79; P = .001). There were 54 vs 258 secondary outcomes: AMI, stroke hospitalizations, or cardiovascular deaths (22.8 vs 22.5 events per 1000 person-years; aHR, 0.98; 95% CI, 0.71-1.34; P = .87). CONCLUSIONS AND RELEVANCE Among patients with diabetes who were receiving metformin, the addition of insulin vs a sulfonylurea was associated with an increased risk of a composite of nonfatal cardiovascular outcomes and all-cause mortality. These findings require further investigation to understand risks associated with insulin use in these patients.

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.

A Review of the Pathophysiology, Classification, and Treatment of Foot Ulcers in Diabetic Patients

IN BRIEF The development of lower extremity ulcers is a well known potential complication for patients with diabetes. This article reviews the common causes of diabetic foot ulceration and discusses methods for assessment and treatment to aid providers in developing appropriate strategies for foot care in individuals with diabetes