Draft Opioid-Prescribing Guidelines for Uncomplicated Normal Spontaneous Vaginal Birth.

Women who experience an uncomplicated vaginal delivery have acute intrapartum pain and variable pain in the immediate postpartum period. Although the Centers for Disease Control and Prevention (CDC) has urged clinicians to improve opioid-prescribing behavior, there are no published clinical practice guidelines for prescribing opioids during labor and delivery and at discharge for patients with uncomplicated normal spontaneous vaginal delivery. To address the knowledge gap regarding guidelines for pain management in this population, we used the national Premiere Health Care Database for deliveries of uncomplicated vaginal births from January 1, 2014, to December 31, 2016, to determine the prevalence of opioid administration. Among the 49,133 women who met inclusion criteria, 78.2% were administered opioids during hospitalization and 29.8% were administered opioids on the day of discharge. Descriptive statistics were generated to document the characteristics of the patients receiving opioids as well as the characteristics of hospitals administering opioids during inpatient labor and delivery and on discharge. Patient-level variables included age group, marital status, race, ethnicity, payer type, and length of stay. Hospital-level variables included bed size, geographic region, teaching status, and urbanicity status. These data were then presented in an electronic Delphi survey to 14 participants. The survey participants were obstetrician-gynecologists identified by the American College of Obstetricians and Gynecologists as being thought leaders in the obstetrics field and who had also demonstrated an active interest in the opioid epidemic and its effect on women's health. After the panelists viewed the opioid administration data, they were presented with an adapted version of the CDC's guidelines for opioid prescribing for chronic pain management. The eight adapted guidelines were constructed to be more relevant and appropriate for the inpatient normal spontaneous vaginal delivery population. After three rounds of the surveying process, seven of the eight adapted guidelines were endorsed by the survey participants. These seven draft consensus guidelines could now be used as a starting point to develop more broadly endorsed and studied guidelines for appropriately managing pain control for women with uncomplicated spontaneous vaginal birth.

Creating a transdisciplinary research center to reduce cardiovascular health disparities in Baltimore, Maryland: lessons learned.

Cardiovascular disease (CVD) disparities continue to have a negative impact on African Americans in the United States, largely because of uncontrolled hypertension. Despite the availability of evidence-based interventions, their use has not been translated into clinical and public health practice. The Johns Hopkins Center to Eliminate Cardiovascular Health Disparities is a new transdisciplinary research program with a stated goal to lower the impact of CVD disparities on vulnerable populations in Baltimore, Maryland. By targeting multiple levels of influence on the core problem of disparities in Baltimore, the center leverages academic, community, and national partnerships and a novel structure to support 3 research studies and to train the next generation of CVD researchers. We also share the early lessons learned in the center's design.

A multi-level system quality improvement intervention to reduce racial disparities in hypertension care and control: study protocol.

BACKGROUND: Racial disparities in blood pressure control have been well documented in the United States. Research suggests that many factors contribute to this disparity, including barriers to care at patient, clinician, healthcare system, and community levels. To date, few interventions aimed at reducing hypertension disparities have addressed factors at all of these levels. This paper describes the design of Project ReD CHiP (Reducing Disparities and Controlling Hypertension in Primary Care), a multi-level system quality improvement project. By intervening on multiple levels, this project aims to reduce disparities in blood pressure control and improve guideline concordant hypertension care. METHODS: Using a pragmatic trial design, we are implementing three complementary multi-level interventions designed to improve blood pressure measurement, provide patient care management services and offer expanded provider education resources in six primary care clinics in Baltimore, Maryland. We are staggering the introduction of the interventions and will use Statistical Process Control (SPC) charting to determine if there are changes in outcomes at each clinic after implementation of each intervention. The main hypothesis is that each intervention will have an additive effect on improvements in guideline concordant care and reductions in hypertension disparities, but the combination of all three interventions will result in the greatest impact, followed by blood pressure measurement with care management support, blood pressure measurement with provider education, and blood pressure measurement only. This study also examines how organizational functioning and cultural competence affect the success of the interventions. DISCUSSION: As a quality improvement project, Project ReD CHiP employs a novel study design that specifically targets multi-level factors known to contribute to hypertension disparities. To facilitate its implementation and improve its sustainability, we have incorporated stakeholder input and tailored components of the interventions to meet the specific needs of the involved clinics and communities. Results from this study will provide knowledge about how integrated multi-level interventions can improve hypertension care and reduce disparities. TRIAL REGISTRATION: ClinicalTrials.gov NCT01566864.

Obese patients overestimate physicians' attitudes of respect.

OBJECTIVE: To evaluate whether obese patients overestimate or underestimate the level of respect that their physicians hold toward them. METHODS: We performed a cross-sectional analysis of data from questionnaires and audio-recordings of visits between primary care physicians and their patients. Using multilevel logistic regression, we evaluated the association between patient BMI and accurate estimation of physician respect. Physician respectfulness was also rated independently by assessing the visit audiotapes. RESULTS: Thirty-nine primary care physicians and 199 of their patients were included in the analysis. The mean patient BMI was 32.8 kg/m2 (SD 8.2). For each 5 kg/m2 increase in BMI, the odds of overestimating physician respect significantly increased [OR 1.32, 95% CI 1.04-1.68, p=0.02]. Few patients underestimated physician respect. There were no differences in ratings of physician respectfulness by independent evaluators of the audiotapes. CONCLUSION: We consider our results preliminary. Patients were significantly more likely to overestimate physician respect as BMI increased, which was not accounted for by increased respectful treatment by the physician. PRACTICE IMPLICATIONS: Among patients who overestimate physician respect, the authenticity of the patient-physician relationship should be questioned.

Impact of patient obesity on the patient-provider relationship.

OBJECTIVE: Health professionals' weight bias may impair obese patients' interactions with providers. However, few studies have examined how negative provider attitudes affect the patient-provider relationship for obese patients. We hypothesized that higher patient body mass index (BMI) would be negatively associated with patient-provider relationship quality. METHODS: We analyzed data from the 2007 Health Tracking Household Survey. BMI was the independent variable, and patient-perceived quality of the patient-provider relationship was the outcome. We performed log-binominal regression analyses accounting for complex survey design to examine the association of BMI with the patient-provider relationship. RESULTS: Of the 15,197 adult survey respondents, the 6427 who answered the quality of care questions were eligible for analysis. Overall, 29% had a normal range BMI, 34% were overweight, and 37% were obese. We found few differences in ratings of the patient-provider relationship for overweight and obese respondents when compared to respondents with a normal range BMI. CONCLUSION: These unexpected findings may have occurred due to patients' inability to perceive providers' weight bias, measurement error in questionnaire items, or decreasing weight bias among health professionals. PRACTICE IMPLICATIONS: Patient's positive perceptions of providers may indicate promise for health professionals acting as motivators of behavior change in obese patients.

The effect of incident antidiabetic regimens on lipid profiles in veterans with type 2 diabetes: a retrospective cohort.

OBJECTIVE: Effects of oral antidiabetic drugs (OADs) on lipids may influence cardiovascular outcomes. Our aim was to compare time to initiation of lipid lowering medication (LLM) and 12-month lipid profiles among new OAD users. METHODS: We identified a retrospective cohort of 17,774 veterans who received care at Veterans Administration (VA) Mid-South Network with a first OAD from 1 January 2000 to 31 December 2007. There were 6917 patients (38.9%) not on a LLM at baseline, and 3871 (56%) had complete covariates. Incident users of sulfonylurea and combination metformin + sulfonylurea were compared to metformin users for time to LLM initiation. Incident users of these OADs and thiazolidendiones were included in comparison of 12-month low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides (TGs), and total cholesterol. All analyses adjusted for demographics, lipids, HbA1C, healthcare utilization, and cardiovascular disease at baseline. RESULTS: The median time to starting LLM was 2.35 years (interquartile range 0.96, 4.6) following metformin initiation and not statistically different for users of sulfonylureas, or combination OADs. Compared to metformin users, 12-month HDL was 1.35 mg/dl (95%CI: -2.01, -0.72) lower and TGs were 5.7% higher (95%CI: 1.5%, 10.0%) for sulfonylurea users; TGs were 24.8% (95%CI: 0.7%, 54.5%) higher for thiazolidinedione users. Statin users had LDL and total cholesterol 16.7 mg/dl (95%CI: -19.9, -13.5) and 18.6 mg/dl (95%CI: -22.1, -15.1) lower than non-statin users, respectively. CONCLUSIONS: Time to LLM initiation was similar between OADs. Metformin use resulted in more favorable lipids at 12 months compared to sulfonylureas or thiazolidinediones.

Glycemic and weight changes after persistent use of incident oral diabetes therapy: a Veterans Administration retrospective cohort study.

PURPOSE: Systematic reviews have reported that sulfonylureas and metformin were as effective in reducing hemoglobin A1c (A1C) as other oral antidiabetic drugs (OADs) in clinical trial populations. Data on comparative effectiveness of OADs in other populations is limited. The objective was to compare the effectiveness of incident OAD regimens in reducing A1C and to compare the effect of OADs on body mass index (BMI). METHODS: Retrospective cohort study using data from the Veterans Affairs Mid-South network (2001-2007). Of 18 205 veterans who filled 19 511 incident OAD prescriptions, 2096 had complete covariates, persisted on their incident treatment for 12 months, and had baseline and 12-month A1C values. For the BMI analysis, 2484 patients had complete information. Incident OAD regimens included metformin and sulfonylureas. Primary outcomes were 12-month A1C and BMI, which were compared controlling for demographic characteristics, baseline A1C and BMI, psychiatric diagnoses, and healthcare utilization. RESULTS: Median [interquartile range (IQR)] A1C decreased from 7.1% [6.5, 7.8] at baseline to 6.5% [6.0, 7.0] at 12 months. Twelve month-A1C in sulfonylurea users was similar to metformin users. The median [IQR] BMI decreased from 31.1 [27.8, 34.9] to 30.7 [27.5, 34.5] kg/m(2). Sulfonylureas were associated with a significantly higher 12-month BMI than metformin (12-month adjusted mean difference: 1.05 kg/m(2), 95%CI: 0.90-1.20, p < 0.0001). CONCLUSIONS: These analyses support the use of metformin as first choice of OAD because of similar glycemic control but improved BMI when compared to sulfonylureas.

Variation in Provider Identification of Obesity by Individual- and Neighborhood-Level Characteristics among an Insured Population.

Objective. The purpose of this study was to examine whether neighborhood- and individual-level characteristics affect providers' likelihood of providing an obesity diagnosis code in their obese patients' claims. Methods. Logistic regressions were performed with obesity diagnosis code serving as the outcome variable and neighborhood characteristics and member characteristics serving as the independent variables (N = 16,151 obese plan members). Results. Only 7.7 percent of obese plan members had an obesity diagnosis code listed in their claims. Members living in neighborhoods with the largest proportions of Blacks were 29 percent less likely to receive an obesity diagnosis (P < .05). The odds of having an obesity diagnosis code were greater among members who were female, aged 44 or below, hypertensive, dyslipidemic, BMI >/= 35 kg/m(2), had a larger number of provider visits, or who lived in an urban area (all P < .05). Conclusions. Most health care providers do not include an obesity diagnosis code in their obese patients' claims. Rates of obesity identification were strongly related to individual characteristics and somewhat associated with neighborhood characteristics.

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.

Patient use of weight-management activities: a comparison of patient and physician assessments.

OBJECTIVE: Examine concordance between patient and physician assessments of patient self-reported use of weight-management activities. METHODS: Analysis of baseline data from a randomized controlled trial of patient and physician interventions to improve patient-physician communication (41 physicians and 274 of their patients). RESULTS: A majority of patients reported regular exercise (55.6%) and efforts to lose weight, such as eating less (63.1%) while physicians only perceived one-third of patients as engaging in those activities (exercise, 36.6%; weight loss, 33.3%). Kappa scores indicated small agreement between patient and physician assessments of patient self-reported use of exercise, mean kappa 0.28 (range 0.15 to 0.40) and no agreement between patient and physician assessments of patient self-reported efforts to lose weight, mean kappa -0.14 (range -0.26 to -0.01). Obese patients were more likely than non-obese patients to report trying to lose weight or exercising regularly (p<0.05), but physicians were less likely to perceive obese patients as engaging in those activities (p<0.05). CONCLUSIONS: Primary care physicians differed considerably from their patients, especially obese patients, in their assessments of patient use of weight-management activities. PRACTICE IMPLICATIONS: These results highlight the importance of improving patient-provider communication about weight-management activities, particularly among obese patients.

Disparity in physician perception of patients' adherence to medications by obesity status.

Physician perception of medication adherence may alter prescribing patterns. Perception of patients has been linked to readily observable factors, such as race and age. Obesity shares a similar stigma to these factors in society. We hypothesized that physicians would perceive patients with a higher BMI as nonadherent to medication. Data were collected from the baseline visit of a randomized clinical trial of patient-physician communication (240 patients and 40 physicians). Physician perception of patient medication adherence was measured on a Likert scale and dichotomized as fully adherent or not fully adherent. BMI was the predictor of interest. We performed Poisson regression analyses with robust variance estimates, adjusting for clustering of patients within physicians, to examine the association between BMI and physician perception of medication adherence. The mean (s.d.) BMI was 32.6 (7.7) kg/m(2). Forty-five percent of patients were perceived as nonadherent to medications by their physicians. Higher BMI was significantly and negatively associated with being perceived as adherent to medication (prevalence ratio (PrR) 0.76, 95% confidence interval (CI): 0.64-0.90; P = 0.002; per 10 kg/m(2) increase in BMI). BMI remained significantly and negatively associated with physician perception of medication adherence after adjustment for patient and physician characteristics (PrR 0.80, 95% CI: 0.66-0.96; P = 0.020). In this study, patients with higher BMI were less likely to be perceived as adherent to medications by their providers. Physician perception of medication adherence has been shown to affect prescribing patterns in other studies. More work is needed to understand how this perception may affect the care of patients with obesity.

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 >or=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.

Physician respect for patients with obesity.

INTRODUCTION: Obesity stigma is common in our society, and a general stigma towards obesity has also been documented in physicians. We hypothesized that physician respect for patients would be lower in patients with higher body mass index (BMI). METHODS: We analyzed data from the baseline visit of 40 physicians and 238 patients enrolled in a randomized controlled trial of patient-physician communication. The independent variable was BMI, and the outcome was physician respect for the patient. We performed Poisson regression analyses with robust variance estimates, accounting for clustering of patients within physicians, to examine the association between BMI and physician ratings of respect for particular patients. RESULTS: The mean (SD) BMI of the patients was 32.9(8.1) kg/m(2). Physicians had low respect for 39% of the participants. Higher BMI was significantly and negatively associated with respect [prevalence ratio (PrR) 0.83, 95% CI: 0.73-0.95; p = 0.006; per 10 kg/m(2) increase in BMI]. BMI remained significantly associated with respect after adjustment for patient age and gender (PrR 0.86, 95%CI: 0.74-1.00; p = 0.049). CONCLUSION: We found that higher patient BMI was associated with lower physician respect. Further research is needed to understand if lower physician respect for patients with higher BMI adversely affects the quality of care.

Use of thiazolidinediones does not affect prostate-specific antigen levels in men with diabetes.

Thiazolidinediones (TZD) have been shown to down-regulate prostate-specific antigen (PSA) levels in prostate cancer cell lines and decrease PSA velocity among prostate cancer patients; however, the effect of TZDs on serum PSA levels among men with diabetes at risk for prostate cancer is unknown. We conducted a retrospective cohort study of veterans receiving care for diabetes between 1999 and 2005 to determine if TZD use affects PSA levels in veterans at risk for prostate cancer. Eligible patients were male, >or=45 years old, taking at least one oral antidiabetic medication, and with two or more recorded PSA values. Patients with a prior history of prostate cancer or prostatectomy were excluded. Of the 13,791 patients included in the adjusted analysis, 2,016 (14.6%) were prescribed a TZD. No effect of cumulative TZD dose on change in PSA was detected (P = 0.26). Increased TZD exposure was not associated with a change in PSA, suggesting that TZD treatment for diabetes is unlikely to affect prostate cancer detection.

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 Spearman's 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/m(2). 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 > or =9th grade had a mean BMI of 27.9 (6.0), P = 0.008. Numeracy was negatively and significantly correlated with BMI (rho = -0.26, P = 0.001). This correlation persisted after adjusting for age, sex, race, income, years of education, and literacy (beta 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.

Insulin use and weight maintenance in well-controlled type 2 diabetes: a prospective cohort study.

Intensification of glycemic control is associated with weight gain, however, less is known about weight change during the maintenance phase of glycemic management. On the basis of current models of energy homeostasis, we hypothesize that insulin use will result in less weight gain than oral antidiabetic agents in patients with well-controlled diabetes. This is a prospective cohort nested within a randomized control trial at an academic clinic, with enrollment from June 2002 to January 2005. A total of 163 patients with type 2 diabetes were enrolled after obtaining glycemic control. Insulin use was assessed by self-report at baseline. Participants were weighed at baseline and five follow-up visits over 24 months. The weight change was compared between insulin users and noninsulin users. The average (s.d.) age was 55 (11), 44% are female and 21% are black. The median duration of diabetes was 5 (0.5-10) years. At baseline, 88 participants (54%) reported insulin use with an average of 69 (6) units/day. Baseline BMI in the insulin users was 35 (6) and 33 (6) in noninsulin patients. Over 24 months, noninsulin patients gained 2.3 additional kilograms compared with insulin users (2.8 kg (6.8) vs. 0.5 kg (6.5), P = 0.065). After adjusting for age, race, sex, baseline weight, intervention status, and change in A1C, insulin users had 2.5 kg less weight gain than noninsulin users (P = 0.033). Less weight gain was observed over 24 months in insulin-treated patients. Whether this effect may be due to central catabolic effects of insulin merits additional confirmatory study and mechanistic investigation.

Development and validation of the Diabetes Numeracy Test (DNT).

BACKGROUND: Low 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. METHODS: The 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. RESULTS: The 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). CONCLUSION: The 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 of numeracy and diabetes control.

BACKGROUND: The influence of a patient's quantitative skills (numeracy) on the management of diabetes is only partially understood. OBJECTIVE: To examine the association between diabetes-related numeracy and glycemic control and other diabetes measurements. DESIGN: Cross-sectional survey. SETTING: 2 primary care and 2 diabetes clinics at 3 medical centers. PARTICIPANTS: 398 adult patients with type 1 or type 2 diabetes mellitus enrolled between March 2004 and November 2005. MEASUREMENTS: Health literacy, general numeracy, and diabetes-related numeracy assessed by using the Rapid Estimate of Adult Literacy in Medicine; the Wide Range Achievement Test, 3rd edition; and the Diabetes Numeracy Test (DNT), respectively. The primary outcome was most recent level of hemoglobin A1c. Additional measurements were diabetes knowledge, perceived self-efficacy of diabetes self-management, and self-management behaviors. RESULTS: The median DNT score was 65% (interquartile range, 42% to 81%). Common errors included misinterpreting glucose meter readings and miscalculating carbohydrate intake and medication dosages. Lower DNT scores were associated with older age, nonwhite race, fewer years of education, lower reported income, lower literacy and general numeracy skills, lower perceived self-efficacy, and selected self-management behaviors. Patients scoring in the lowest DNT quartile (score <42%) had a median hemoglobin A1c level of 7.6% (interquartile range, 6.5% to 9.0%) compared with 7.1% (interquartile range, 6.3% to 8.1%) in those scoring in the highest quartile (P = 0.119 for trend). A regression analysis adjusted for age, sex, race, income, and other factors found a modest association between DNT score and hemoglobin A1c level. LIMITATION: Causality cannot be determined in this cross-sectional study, especially with its risk for unmeasured confounding variables. CONCLUSION: Poor numeracy skills were common in patients with diabetes. Low diabetes-related numeracy skills were associated with worse perceived self-efficacy, fewer self-management behaviors, and possibly poorer glycemic control.