Impact of a Telephonic Intervention to Improve Diabetes Control on Health Care Utilization and Cost for Adults in South Bronx, New York

OBJECTIVE

Self-management education and support are essential for improved diabetes control. A 1-year randomized telephonic diabetes self-management intervention (Bronx A1C) among a predominantly Latino and African American population in New York City was found effective in improving blood glucose control. To further those findings, this current study assessed the intervention's impact in reducing health care utilization and costs over 4 years.

RESEARCH DESIGN AND METHODS

We measured inpatient (n = 816) health care utilization for Bronx A1C participants using an administrative data set containing all hospital discharges for New York State from 2006 to 2014. Multilevel mixed modeling was used to assess changes in health care utilization and costs between the telephonic diabetes intervention (Tele/Pr) arm and print-only (PrO) control arm.

RESULTS

During follow-up, excess relative reductions in all-cause hospitalizations for the Tele/Pr arm compared with PrO arm were statistically significant for odds of hospital use (odds ratio [OR] 0.89; 95% CI 0.82, 0.97; P < 0.01), number of hospital stays (rate ratio [RR] 0.90; 95% CI 0.81, 0.99; P = 0.04), and hospital costs (RR 0.90; 95% CI 0.84, 0.98; P = 0.01). Reductions in hospital use and costs were even stronger for diabetes-related hospitalizations. These outcomes were not significantly related to changes observed in hemoglobin A_1c during individuals' participation in the 1-year intervention.

CONCLUSIONS

These results indicate that the impact of the Bronx A1C intervention was not just on short-term improvements in glycemic control but also on long-term health care utilization. This finding is important because it suggests the benefits of the intervention were long-lasting with the potential to not only reduce hospitalizations but also to lower hospital-associated costs.

Heart Age, Cardiovascular Disease Risk, and Disparities by Sex and Race/Ethnicity Among New York City Adults

OBJECTIVES

Cardiovascular disease (CVD) is the leading cause of mortality in the United States. The risk for developing CVD is usually calculated and communicated to patients as a percentage. The calculation of heart age-defined as the predicted age of a person's vascular system based on the person's CVD risk factor profile-is an alternative method for expressing CVD risk. We estimated heart age among adults aged 30-74 in New York City and examined disparities in excess heart age by race/ethnicity and sex.

METHODS

We applied data from the 2011, 2013, and 2015 New York State Behavioral Risk Factor Surveillance System to the non-laboratory-based Framingham risk score functions to calculate 10-year CVD risk and heart age by sex, race/ethnicity, and selected sociodemographic groups and risk factors.

RESULTS

Of 6117 men and women in the study sample, the average heart age was 5.7 years higher than the chronological age, and 2631 (43%) adults had a predicted heart age ≥5 years older than their chronological age. Mean excess heart age increased with age (from 0.7 year among adults aged 30-39 to 11.2 years among adults aged 60-74) and body mass index (from 1.1 year among adults with normal weight to 11.8 years among adults with obesity). Non-Latino white women had the lowest mean excess heart age (2.3 years), and non-Latino black men and women had the highest excess heart age (8.4 years).

CONCLUSIONS

Racial/ethnic and sex disparities in CVD risk persist among adults in New York City. Use of heart age at the population level can support public awareness and inform targeted programs and interventions for population subgroups most at risk for CVD.

Using Indirect Measures to Identify Geographic Hot Spots of Poor Glycemic Control: Cross-sectional Comparisons With an A1C Registry

OBJECTIVE

Focusing health interventions in places with suboptimal glycemic control can help direct resources to neighborhoods with poor diabetes-related outcomes, but finding these areas can be difficult. Our objective was to use indirect measures versus a gold standard, population-based A1C registry to identify areas of poor glycemic control.

RESEARCH DESIGN AND METHODS

Census tracts in New York City (NYC) were characterized by race, ethnicity, income, poverty, education, diabetes-related emergency visits, inpatient hospitalizations, and proportion of adults with diabetes having poor glycemic control, based on A1C >9.0% (75 mmol/mol). Hot spot analyses were then performed, using the Getis-Ord Gi* statistic for all measures. We then calculated the sensitivity, specificity, positive and negative predictive values, and accuracy of using the indirect measures to identify hot spots of poor glycemic control found using the NYC A1C Registry data.

RESULTS

Using A1C Registry data, we identified hot spots in 42.8% of 2,085 NYC census tracts analyzed. Hot spots of diabetes-specific inpatient hospitalizations, diabetes-specific emergency visits, and age-adjusted diabetes prevalence estimated from emergency department data, respectively, had 88.9%, 89.6%, and 89.5% accuracy for identifying the same hot spots of poor glycemic control found using A1C Registry data. No other indirect measure tested had accuracy >80% except for the proportion of minority residents, which had 86.2% accuracy.

CONCLUSIONS

Compared with demographic and socioeconomic factors, health care utilization measures more accurately identified hot spots of poor glycemic control. In places without a population-based A1C registry, mapping diabetes-specific health care utilization may provide actionable evidence for targeting health interventions in areas with the highest burden of uncontrolled diabetes.

Associations of Residential Socioeconomic, Food, and Built Environments With Glycemic Control in Persons With Diabetes in New York City From 2007-2013

In the present study, we examined the longitudinal associations between residential environmental factors and glycemic control in 182,756 adults with diabetes in New York City from 2007 to 2013. Glycemic control was defined as a hemoglobin A1c (HbA1c) level less than 7%. We constructed residential-level measures and performed principle component analysis to formulate a residential composite score. On the basis of this score, we divided residential areas into quintiles, with the lowest and highest quintiles reflecting the least and most advantaged residential environments, respectively. Several residential-level environmental characteristics, including more advantaged socioeconomic conditions, greater ratio of healthy food outlets to unhealthy food outlets, and residential walkability were associated with increased glycemic control. Individuals who lived continuously in the most advantaged residential areas took less time to achieve glycemic control compared with the individuals who lived continuously in the least advantaged residential areas (9.9 vs. 11.5 months). Moving from less advantaged residential areas to more advantaged residential areas was related to improved diabetes control (decrease in HbA1c = 0.40%, 95% confidence interval: 0.22, 0.55), whereas moving from more advantaged residential areas to less advantaged residential areas was related to worsening diabetes control (increase in HbA1c = 0.33%, 95% confidence interval: 0.24, 0.44). These results show that residential areas with greater resources to support healthy food and residential walkability are associated with improved glycemic control in persons with diabetes.

Self-blood pressure monitoring in an urban, ethnically diverse population: a randomized clinical trial utilizing the electronic health record

BACKGROUND

Hypertension is a leading risk factor for cardiovascular disease. Although control rates have improved over time, racial/ethnic disparities in hypertension control persist. Self-blood pressure monitoring, by itself, has been shown to be an effective tool in predominantly white populations, but less studied in minority, urban communities. These types of minimally intensive approaches are important to test in all populations, especially those experiencing related health disparities, for broad implementation with limited resources.

METHODS AND RESULTS

The New York City Health Department in partnership with community clinic networks implemented a randomized clinical trial (n=900, 450 per arm) to investigate the effectiveness of self-blood pressure monitoring in medically underserved and largely black and Hispanic participants. Intervention participants received a home blood pressure monitor and training on use, whereas control participants received usual care. After 9 months, systolic blood pressure decreased (intervention, 14.7 mm Hg; control, 14.1 mm Hg; P=0.70). Similar results were observed when incorporating longitudinal data and calculating a mean slope over time. Control was achieved in 38.9% of intervention and 39.1% of control participants at the end of follow-up; the time-to-event experience of achieving blood pressure control in the intervention versus control groups were not different from each other (logrank P value =0.91).

CONCLUSIONS

Self-blood pressure monitoring was not shown to improve control over usual care in this largely minority, urban population. The patient population in this study, which included a high proportion of Hispanics and uninsured persons, is understudied. Results indicate these groups may have additional meaningful barriers to achieving blood pressure control beyond access to the monitor itself.

CLINICAL TRIAL REGISTRATION

http://clinicaltrials.gov. Unique Identifier: NCT01123577.

Incidence of self-reported diabetes in New York City, 2002, 2004, and 2008

Introduction

Prevalence and incidence of diabetes among adults are increasing in the United States. The purpose of this study was to estimate the incidence of self-reported diabetes in New York City, examine factors associated with diabetes incidence, and estimate changes in the incidence over time.

Methods

We used data from the New York City Community Health Survey in 2002, 2004, and 2008 to estimate the age-adjusted incidence of self-reported diabetes among 24,384 adults aged 18 years or older. Multiple logistic regression analysis was performed to examine factors associated with incident diabetes.

Results

Survey results indicated that the age-adjusted incidence of diabetes per 1,000 population was 9.4 in 2002, 11.9 in 2004, and 8.6 in 2008. In multivariable-adjusted analysis, diabetes incidence was significantly associated with being aged 45 or older, being black or Hispanic, being overweight or obese, and having less than a high school diploma.

Conclusion

Our results suggest that the incidence of diabetes in New York City may be stabilizing. Age, black race, Hispanic ethnicity, elevated body mass index, and low educational attainment are risk factors for diabetes. Large-scale implementation of prevention efforts addressing obesity and sedentary lifestyle and targeting racial/ethnic minority groups and those with low educational attainment are essential to control diabetes in New York City.

Metabolic syndrome among adults in New York City, 2004 New York City Health and Nutrition Examination Survey

INTRODUCTION

The objective of this study was to describe the prevalence of and factors associated with metabolic syndrome among adult New York City residents.

METHODS

The 2004 New York City Health and Nutrition Examination Survey was a population-based, cross-sectional study of noninstitutionalized New York City residents aged 20 years or older. We examined the prevalence of metabolic syndrome and its components as defined by the National Cholesterol Education Program's Adult Treatment Panel III revised guidelines, according to demographic subgroups and comorbid diagnoses in a probability sample of 1,263 participants. We conducted bivariable and multivariable analyses to identify factors associated with metabolic syndrome.

RESULTS

The age-adjusted prevalence of metabolic syndrome was 26.7% (95% confidence interval, 23.7%-29.8%). Prevalence was highest among Hispanics (33.9%) and lowest among whites (21.8%). Prevalence increased with age and body mass index and was higher among women (30.1%) than among men (22.9%). More than half (55.4%) of women and 33.0% of men with metabolic syndrome had only 3 metabolic abnormalities, 1 of which was abdominal obesity. The most common combination of metabolic abnormalities was abdominal obesity, elevated fasting blood glucose, and elevated blood pressure. Adjusting for other factors, higher body mass index, Asian race, and current smoking were positively associated with metabolic syndrome; alcohol use was inversely associated with metabolic syndrome among women but increased the likelihood of metabolic syndrome among men.

CONCLUSION

Metabolic syndrome is pervasive among New York City adults, particularly women, and is associated with modifiable factors. These results identify population subgroups that could be targeted for prevention and provide a benchmark for assessing such interventions.

The influence of maternal weight and glucose tolerance on infant birthweight in Latino mother-infant pairs

OBJECTIVES

We assessed the influence of maternal anthropometric and metabolic variables, including glucose tolerance, on infant birthweight.

METHODS

In our prospective, population-based cohort study of 1041 Latino mother-infant pairs, we used standardized interviews, anthropometry, metabolic assays, and medical record reviews. We assessed relationships among maternal sociodemographic, prenatal care, anthropometric, and metabolic characteristics and birthweight with analysis of variance and bivariate and multivariate linear regression analyses.

RESULTS

Forty-two percent of women in this study entered pregnancy overweight or obese; at least 36% exceeded weight-gain recommendations. Twenty-seven percent of the women had at least some degree of glucose abnormality, including 6.8% who had gestational diabetes. Maternal multiparity, height, weight, weight gain, and 1-hour screening glucose levels were significant independent predictors of infant birthweight after adjustment for gestational age.

CONCLUSION

Studies of birthweight should account for maternal glucose level. Given the increased risk of adverse maternal and infant outcomes associated with excessive maternal weight, weight gain, and glucose intolerance, and the high prevalence of these conditions and type 2 diabetes among Latinas, public health professionals have unique opportunities for prevention through prenatal and postpartum interventions.

Missed opportunities for type 2 diabetes mellitus screening among women with a history of gestational diabetes mellitus

OBJECTIVES

We sought to determine rates and factors associated with screening for type 2 diabetes mellitus (DM) in women with a history of gestational diabetes mellitus.

METHODS

We retrospectively studied women with diagnosed gestational diabetes mellitus who delivered at a university-affiliated hospital (n=570). Data sources included medical and administrative record review. Main outcome measures were the frequency of any type of glucose testing at least 6 weeks after delivery and the frequency of recommended glucose testing. We assessed demographic data, past medical history, and prenatal and postpartum care characteristics.

RESULTS

Rates of glucose testing after delivery were low. Any type of glucose testing was performed at least once after 38% of deliveries, and recommended glucose testing was performed at least once after 23% of deliveries. Among women with at least 1 visit to the health care system after delivery (n=447), 42% received any type of glucose test at least once, and 35% received a recommended glucose test at least once. Factors associated with testing were being married, having a visit with an endocrinologist after delivery, and having more visits after delivery.

CONCLUSIONS

These findings suggest that most women with gestational diabetes mellitus are not screened for type 2 DM after delivery. Opportunities for DM prevention and early treatment are being missed.

Does diabetes care compete with the provision of women's preventive care services?

OBJECTIVE

Care for chronic diseases may compete with preventive health care. To test this hypothesis, we examined the association between diabetes-related processes of care and preventive care in women.

RESEARCH DESIGN AND METHODS

Using data from a prospective cohort study of diabetes care in managed care settings, we reviewed the care 540 diabetic women received from 355 primary care providers within 14 provider groups from one health plan. Of the 540 women, 278 were eligible to receive mammograms and 314 were eligible to receive Pap smears. Mammography performance was measured as at least one mammogram over a 2-year period and Pap performance was measured as at least one Pap smear over a 3-year period. To assess the association between diabetes-related processes of care and preventive services, we used hierarchical logistic regression models, accounted for clustering within provider groups, and adjusted for patient age, race, income and education level, diabetes treatment and duration, and health status, as well as physician age, sex, years of practice, and specialty. Diabetes-related processes of care were defined as dilated retinal examinations, urine microalbumin/protein testing, foot examinations, lipid and HbA(1c) testing, recommendations to take aspirin, and influenza vaccinations received over a 1-year period.

RESULTS

In this cohort, 73% of eligible women received mammograms and 56% received Pap smears. After adjustment of models, better diabetes-related processes of care, better health status, and non-Medicaid insurance were associated with mammography performance. Better diabetes-related processes of care, younger patient age, and any visit to a gynecologist were associated with Pap performance.

CONCLUSIONS

Better processes of diabetes care were associated with better women's preventive health care. Diabetes management did not compete with sex-specific screening.

A multivariate logistic regression equation to screen for dysglycaemia: development and validation

AIMS

To develop and validate an empirical equation to screen for dysglycaemia [impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and undiagnosed diabetes].

METHODS

A predictive equation was developed using multiple logistic regression analysis and data collected from 1032 Egyptian subjects with no history of diabetes. The equation incorporated age, sex, body mass index (BMI), post-prandial time (self-reported number of hours since last food or drink other than water), systolic blood pressure, high-density lipoprotein (HDL) cholesterol and random capillary plasma glucose as independent covariates for prediction of dysglycaemia based on fasting plasma glucose (FPG)>or=6.1 mmol/l and/or plasma glucose 2 h after a 75-g oral glucose load (2-h PG)>or=7.8 mmol/l. The equation was validated using a cross-validation procedure. Its performance was also compared with static plasma glucose cut-points for dysglycaemia screening.

RESULTS

The predictive equation was calculated with the following logistic regression parameters: P=1+1/(1+e-X)=where X=-8.3390+0.0214 (age in years)+0.6764 (if female)+0.0335 (BMI in kg/m2)+0.0934 (post-prandial time in hours)+0.0141 (systolic blood pressure in mmHg)-0.0110 (HDL in mmol/l)+0.0243 (random capillary plasma glucose in mmol/l). The cut-point for the prediction of dysglycaemia was defined as a probability>or=0.38. The equation's sensitivity was 55%, specificity 90% and positive predictive value (PPV) 65%. When applied to a new sample, the equation's sensitivity was 53%, specificity 89% and PPV 63%.

CONCLUSIONS

This multivariate logistic equation improves on currently recommended methods of screening for dysglycaemia and can be easily implemented in a clinical setting using readily available clinical and non-fasting laboratory data and an inexpensive hand-held programmable calculator.

The efficacy and cost of alternative strategies for systematic screening for type 2 diabetes in the U.S. population 45-74 years of age

OBJECTIVE

To simulate the outcomes of alternative strategies for screening the U.S. population 45-74 years of age for type 2 diabetes.

RESEARCH DESIGN AND METHODS

We simulated screening with random plasma glucose (RPG) and cut points of 100, 130, and 160 mg/dl and a multivariate equation including RPG and other variables. Over 15 years, we simulated screening at intervals of 1, 3, and 5 years. All positive screening tests were followed by a diagnostic fasting plasma glucose or an oral glucose tolerance test. Outcomes include the numbers of false-negative, true-positive, and false-positive screening tests and the direct and indirect costs.

RESULTS

At year 15, screening every 3 years with an RPG cut point of 100 mg/dl left 0.2 million false negatives, an RPG of 130 mg/dl or the equation left 1.3 million false negatives, and an RPG of 160 mg/dl left 2.8 million false negatives. Over 15 years, the absolute difference between the most sensitive and most specific screening strategy was 4.5 million true positives and 476 million false-positives. Strategies using RPG cut points of 130 mg/dl or the multivariate equation every 3 years identified 17.3 million true positives; however, the equation identified fewer false-positives. The total cost of the most sensitive screening strategy was $42.7 billion and that of the most specific strategy was $6.9 billion.

CONCLUSIONS

Screening for type 2 diabetes every 3 years with an RPG cut point of 130 mg/dl or the multivariate equation provides good yield and minimizes false-positive screening tests and costs.

Glycemia and the Quality of Well-Being in Patients with Diabetes

OBJECTIVES

To investigate the cross-sectional relationships among self-reported frequencies of symptomatic hyperglycemia and hypoglycemia, HbA1c, and symptoms in the Quality of Well-Being Self-Administered (QWB-SA), and to examine the associations among these measures of glycemia and health-utility scores.

METHODS

The study group included 1522 patients with diabetes who attended University of Michigan Health System clinics. Published studies were reviewed to identify symptoms in the QWB-SA that might be associated with measures of glycemia. Linear-regression analyses were performed to evaluate the strength of the associations among the frequency of self-reported measures of glycemia, QWB-SA symptoms, and QWB-SA-derived health-utility scores.

RESULTS

Frequency of hyperglycemic symptoms was associated with 3% of the variance in the QWB-SA-derived health-utility score in type-1 diabetes and with 5% of the variance in type-2 diabetes. Frequency of hypoglycemic symptoms was not associated with the QWB-SA-derived health-utility score in type-1 diabetes but was associated with 1% of the variance in type-2 diabetes. HbAlc levels were not significantly associated with QWB-SA-derived health-utility scores. After controlling for age, gender, and complications, frequency of hyperglycemic symptoms was significantly associated with QWB-SA-derived health-utility scores in type-1 and type-2 diabetes.

CONCLUSIONS

Reported frequency of hyperglycemic symptoms is associated with symptoms included in the QWB-SA and with QWB-SA-derived health-utility scores. The QWB-SA may be an appropriate measure to assess the health burden of hyperglycemia.

Opportunistic screening for diabetes in routine clinical practice

OBJECTIVE

Since 1997, the American Diabetes Association has recommended that nondiabetic individuals >/=45 years of age be screened for diabetes at least every 3 years. We sought to characterize the frequency, methods, and results of diabetes screening in routine clinical practice.

RESEARCH DESIGN AND METHODS

We studied opportunistic screening in nondiabetic members of a health maintenance organization >/=45 years of age who were assigned to a large, integrated, academic health care delivery system. Screening was defined as the first glucose, HbA(1c), or oral glucose tolerance test (OGTT) performed between 1 January 1998 and 31 December 2000. Chart review was performed to determine the prevalence of diabetes risk factors and to describe follow-up.

RESULTS

Of 8,286 nondiabetic patients >/=45 years of age, 69% (n = 5,752) were screened. The frequency of screening was greater in patients with one or more primary care visits and increased with age. Women were more likely to be screened than men, and patients with at least one diabetes risk factor were more likely to be screened than those without risk factors. Random plasma glucose was the most common screening test (95%). Four percent (n = 202) of those screened had abnormal results. Only 38% (n = 77) of those with abnormal results received appropriate follow-up, and 17% (n = 35) were diagnosed with diabetes within 6 months of screening. The yield of screening was very low (0.6%, 35 of 5,752).

CONCLUSIONS

Despite frequent screening and appropriate targeting of high-risk patients, follow-up of patients with abnormal results is uncommon and the yield of screening is low. Interventions are needed to help physicians recognize and provide appropriate follow-up for patients with potentially abnormal random glucose levels.

Improving diabetes processes of care in managed care

OBJECTIVE

To evaluate the impact of systematic patient evaluation and patient and provider feedback on the processes and intermediate outcomes of diabetes care in Independent Practice Association model internal medicine practices.

RESEARCH DESIGN AND METHODS

Nine practices providing care to managed care patients were randomly assigned as intervention or comparison sites. Intervention-site subjects had Annual Diabetes Assessment Program (ADAP) assessments (HbA(1c), blood pressure, lipids, smoking, retinal photos, urine microalbumin, and foot examination) at years 1 and 2. Comparison-site subjects had ADAP assessments at year 2. At Intervention sites, year 1 ADAP results were reviewed with subjects, mailed to providers, and incorporated into electronic medical records with guideline-generated suggestions for treatment and follow-up. Medical records were evaluated for both groups for the year before both the year 1 and year 2 ADAP assessments. Processes and intermediate outcomes were compared using linear and logistic mixed hierarchical models.

RESULTS

Of 284 eligible subjects, 103 of 173 (60%) at the Intervention sites and 71 of 111 (64%) at the comparison sites participated; 83 of 103 (81%) of the intervention-site subjects returned for follow-up at year 2. Performance of the six recommended assessments improved in intervention-site subjects at year 2 compared with year 1 (5.8 vs. 4.3, P = 0.0001) and compared with comparison-site subjects at year 2 (4.2, P = 0.014). No significant changes were noted in intermediate outcomes.

CONCLUSIONS

The ADAP significantly improved processes of care but not intermediate outcomes. Additional interventions are needed to improve intermediate outcomes.

The direct medical cost of type 2 diabetes

OBJECTIVE

To describe the direct medical costs associated with type 2 diabetes, as well as its treatments, complications, and comorbidities.

RESEARCH DESIGN AND METHODS

We studied a random sample of 1,364 subjects with type 2 diabetes who were members of a Michigan health maintenance organization. Demographic characteristics, duration of diabetes, diabetes treatments, glycemic control, complications, and comorbidities were assessed by surveys and medical chart reviews. Annual resource utilization and costs were assessed using health insurance claims. The log-transformed annual direct medical costs were fitted by multiple linear regression to indicator variables for demographics, treatments, glycemic control, complications, and comorbidities.

RESULTS

The median annual direct medical costs for subjects with diet-controlled type 2 diabetes, BMI 30 kg/m(2), and no microvascular, neuropathic, or cardiovascular complications were 1,700 dollars for white men and 2,100 dollars for white women. A 10-kg/m(2) increase in BMI, treatment with oral antidiabetic or antihypertensive agents, diabetic kidney disease, cerebrovascular disease, and peripheral vascular disease were each associated with 10-30% increases in cost. Insulin treatment, angina, and MI were each associated with 60-90% increases in cost. Dialysis was associated with an 11-fold increase in cost.

CONCLUSIONS

Insulin treatment and diabetes complications have a substantial impact on the direct medical costs of type 2 diabetes. The estimates presented in this model may be used to analyze the cost-effectiveness of interventions for type 2 diabetes.

Community-based screening for diabetes in Michigan

OBJECTIVE

To describe and evaluate a community-based diabetes screening program supported by the Michigan Department of Community Health.

RESEARCH DESIGN AND METHODS

Between 1 June 1999 and 31 December 1999, community screening for diabetes was conducted by voluntary organizations using a standard protocol, American Diabetes Association (ADA) questionnaires, and ADA capillary plasma glucose criteria.

RESULTS

A total of 3506 individuals were screened, 14% of whom did not meet criteria for screening. Of the 3031 individuals appropriately screened, 57% were classified as being at high risk based on the ADA questionnaire and 5% had positive screening tests based on ADA capillary plasma glucose criteria. Despite systematic follow-up, the screening program's yield of individuals with undiagnosed diabetes was <1%.

CONCLUSIONS

Community screening for diabetes conducted according to ADA recommendations was extremely inefficient at identifying individuals with undiagnosed diabetes. The ADA diabetes screening questionnaire resulted in many false positive tests, and the ADA criteria for positive plasma glucose tests likely missed a substantial portion of individuals with undiagnosed diabetes. Relying on biochemical tests such as random plasma glucose, changing the criteria for a positive plasma glucose test, targeting racial and ethnic minority groups, and targeting medically underserved individuals might improve the yield of community-based diabetes screening.

Valuing health-related quality of life in diabetes

OBJECTIVE

Cost-utility analyses use information on health utilities to compare medical treatments that have different clinical outcomes and impacts on survival. The purpose of this study was to describe the health utilities associated with diabetes and its treatments, complications, and comorbidities.

RESEARCH DESIGN AND METHODS

We studied 2,048 subjects with type 1 and type 2 diabetes recruited from specialty clinics at a university medical center. We administered a questionnaire to each individual to assess demographic characteristics, type and duration of diabetes, treatments, complications, and comorbidities, and we used the Self-Administered Quality of Well Being index (QWB-SA) to calculate a health utility score. We then created regression models to fit the QWB-SA-derived health utility scores to indicator variables for type 1 and type 2 diabetes and each demographic variable, treatment, and complication. The coefficients were arranged in clinically meaningful ways to develop models to describe penalties from the health utility scores for nonobese diabetic men without additional treatments, complications, or comorbidities.

RESULTS

The utility scores for nonobese diet-controlled men and women with type 2 diabetes and no microvascular, neuropathic, or cardiovascular complications were 0.69 and 0.65, respectively. The utility scores for men and women with type 1 diabetes and no complications were slightly lower (0.67 and 0.64, respectively). Blindness, dialysis, symptomatic neuropathy, foot ulcers, amputation, debilitating stroke, and congestive heart failure were associated with lower utility scores.

CONCLUSIONS

Major diabetes complications are associated with worse health-related quality of life. The health utility scores provided should facilitate studies of the health burden of diabetes and the cost-utility of alternative strategies for the prevention and treatment of diabetes.

A multivariate logistic regression equation to screen for diabetes: development and validation

OBJECTIVE

To develop and validate an empirical equation to screen for diabetes.

RESEARCH DESIGN AND METHODS

A predictive equation was developed using multiple logistic regression analysis and data collected from 1,032 Egyptian subjects with no history of diabetes. The equation incorporated age, sex, BMI, postprandial time (self-reported number of hours since last food or drink other than water), and random capillary plasma glucose as independent covariates for prediction of undiagnosed diabetes. These covariates were based on a fasting plasma glucose level >/=126 mg/dl and/or a plasma glucose level 2 h after a 75-g oral glucose load >/=200 mg/dl. The equation was validated using data collected from an independent sample of 1,065 American subjects. Its performance was also compared with that of recommended and proposed static plasma glucose cut points for diabetes screening.

RESULTS

The predictive equation was calculated with the following logistic regression parameters: P = 1/(1 - e(-x)), where x = -10.0382 + [0.0331 (age in years) + 0.0308 (random plasma glucose in mg/dl) + 0.2500 (postprandial time assessed as 0 to >/=8 h) + 0.5620 (if female) + 0.0346 (BMI)]. The cut point for the prediction of previously undiagnosed diabetes was defined as a probability value >/=0.20. The equation's sensitivity was 65%, specificity 96%, and positive predictive value (PPV) 67%. When applied to a new sample, the equation's sensitivity was 62%, specificity 96%, and PPV 63%.

CONCLUSIONS

This multivariate logistic equation improves on currently recommended methods of screening for undiagnosed diabetes and can be easily implemented in a inexpensive handheld programmable calculator to predict previously undiagnosed diabetes.

Does microalbuminuria predict diabetic nephropathy?

OBJECTIVE

To describe risk factors associated with microalbuminuria (MA) in subjects with diabetes, investigate the predictive value of MA as a marker of risk for diabetic nephropathy (DN), and define risk factors associated with the development and progression of MA.

RESEARCH DESIGN AND METHODS

We conducted a prospective longitudinal study of 23 diabetic subjects with persistent MA and 209 diabetic subjects without MA who attended diabetes clinics at the University of Michigan Medical Center in 1989 and 1990. Both groups were examined at baseline and after 7 years. At baseline, urinary albumin-to-creatinine ratios were studied in random, first morning, and 24-h urine samples. At follow-up, a 12-h overnight urine sample was collected and analyzed for albumin and creatinine. At baseline, MA was defined by at least two separate urine specimens with albumin-to-creatinine ratios between 30 and 299 microg albumin per milligram of creatinine.

RESULTS

MA regressed in 56% of subjects with baseline MA without systematic application of corrective measures and developed in 16% of subjects without baseline MA. The predictive value positive of MA as a marker of risk for DN was 43%, and the predictive value negative was 77%. In the combined cohort, the incidence and progression of MA were significantly associated with poor glycemic control and duration of diabetes between 10 and 14 years.

CONCLUSIONS

MA may not be as sensitive and specific a predictor of DN as previously suggested. Other markers of risk for DN are needed for optimal clinical management.

Reduced pancreatic polypeptide response to hypoglycemia and amylin response to arginine in subjects with a mutation in the HNF-4alpha/MODY1 gene

Subjects with the Q268X mutation in the hepatocyte nuclear factor (HNF)-4alpha gene (RW pedigree/maturity-onset diabetes of the young [MODY]-1) have diminished insulin and glucagon secretory responses to arginine. To determine if pancreatic polypeptide (PP) secretion is likewise involved, we studied PP responses to insulin-induced hypoglycemia in 17 RW pedigree members: 6 nondiabetic mutation-negative [ND(-)], 4 nondiabetic mutation-positive [ND(+)], and 7 diabetic mutation-positive [D(+)]. Subjects received 0.08 U/kg body wt human regular insulin as an intravenous bolus to produce moderate self-limited hypoglycemia. PP areas under the curve (PP-AUCs) were compared among groups. With hypoglycemia, the PP-AUC was lower in the D(+) group (14,907 +/- 6,444 pg/ml, P = 0.03) and the ND(+) group (14,622 +/- 6,015 pg/ml, P = 0.04) compared with the ND(-) group (21,120 +/- 4,158 pg/ml). In addition, to determine if the beta-cell secretory defect in response to arginine involves amylin in addition to insulin secretion, we analyzed samples from 17 previously studied RW pedigree subjects. We compared the AUCs during arginine infusions for the 3 groups both at euglycemia and hyperglycemia as well as their C-peptide-to-amylin ratios. The D(+) and ND(+) groups had decreased amylin AUCs during both arginine infusions compared with the ND(-) group, but had similar C-peptide-to-amylin ratios. These results suggest that the HNF-4alpha mutation in the RW/MODY1 pedigree confers a generalized defect in islet cell function involving PP cells in addition to beta- and alpha-cells, and beta-cell impairment involving proportional deficits in insulin and amylin secretion.