Review of the performance of methods to identify diabetes cases among vital statistics, administrative, and survey data

Disparity in diabetes risk across Native Hawaiians and different Asian groups: the multiethnic cohort

We evaluated the impact of body mass index (BMI) and lifestyle risk factors on ethnic disparity in diabetes incidence among 89 198 Asian, Native Hawaiian, and white participants of the Multiethnic Cohort who completed multiple questionnaires. After 12 years of follow-up, 11 218 new cases were identified through self-report and health plan linkages. BMI was lowest in Chinese/Koreans, Japanese, and Filipinos (22.4, 23.5, and 23.9 kg/m(2)). Using Cox regression, the unadjusted hazard ratios were 1.9 (Chinese/Korean), 2.1 (Japanese, Mixed-Asian), 2.2 (Filipino), 2.5 (Native Hawaiian), and 2.6 (part-Asian) as compared with whites. With BMI added, the risk for Japanese, Filipinos, Chinese/Koreans, and mixed-Asians increased (8%-42%) but declined in part-Asians and Native Hawaiians (17%-31%). When lifestyle and dietary factors were also included, the risk was attenuated in all groups (6%-14%). Despite their lower BMI, Asian Americans have a higher diabetes risk than whites, but dietary and lifestyle factors do not account for the excess risk.

In-hospital mortality among patients with type 2 diabetes mellitus and acute myocardial infarction: results from the national inpatient sample, 2000-2010

Background

Case‐fatality rates in acute myocardial infarction (AMI) have significantly decreased; however, the prevalence of diabetes mellitus (DM), a risk factor for AMI, has increased. The purposes of the present study were to assess the prevalence and clinical impact of DM among patients hospitalized with AMI and to estimate the impact of important clinical characteristics associated with in‐hospital mortality in patients with AMI and DM.

Methods and Results

We used the National Inpatient Sample to estimate trends in DM prevalence and in‐hospital mortality among 1.5 million patients with AMI from 2000 to 2010, using survey data‐analysis methods. Clinical characteristics associated with in‐hospital mortality were identified using multivariable logistic regression. There was a significant increase in DM prevalence among AMI patients (year 2000, 22.2%; year 2010, 29.6%, P_trend<0.0001). AMI patients with DM tended to be older and female and to have more cardiovascular risk factors. However, age‐standardized mortality decreased significantly from 2000 (8.48%) to 2010 (4.95%) (P_trend<0.0001). DM remained independently associated with mortality (adjusted odds ratio 1.069, 95% CI 1.051 to 1.087; P<0.0001). The adverse impact of DM on in‐hospital mortality was unchanged over time. Decreased death risk over time was greatest among women and elderly patients. Among younger patients of both sexes, there was a leveling off of this decrease in more recent years.

Conclusions

Despite increasing DM prevalence and disease burden among AMI patients, in‐hospital mortality declined significantly from 2000 to 2010. The adverse impact of DM on mortality remained unchanged overall over time but was age and sex dependent.

Identifying persons with diabetes who could benefit from a palliative approach to care

OBJECTIVE

To determine the need for diabetes mellitus palliative care, we identified persons with a diagnosis of diabetes who accessed palliative care programs and those who may have benefited from a palliative approach to care.

METHODS

This retrospective, descriptive research used 6 linked databases comprising 66 634 Nova Scotians from 3 health districts who died between 1995 and 2009, each with access to a palliative care program and diabetes centres.

RESULTS

The percentage of persons with diabetes enrolled in palliative care increased from 3.2% in 1995 to 34.3% in 2009; 31.5% were enrolled within their last 2 weeks of life. Most did not have their diabetes recorded in palliative data. Among the 5353 persons with a diagnosis of diabetes who died between 2005 and 2009, 61.0% were in the Diabetes Care Program of Nova Scotia registry. An additional 19.6% were identified in the Cardiovascular Health Nova Scotia registry, and a further 3.7% in palliative data. Applying the criteria of Rosenwax et al to the 5353, 65.8% to 97.9% may have benefitted from a palliative approach.

CONCLUSIONS

Rates of palliative enrollment for persons with diabetes are increasing. Diabetes care providers need to prepare patients and their families for changes in diabetes management that will be beneficial as end of life approaches. Collaboration among chronic disease programs, palliative care and primary care is advised to identify persons at end of life who have diabetes and to develop and implement care guidelines for this population.

Late cardiovascular complications after hematopoietic cell transplantation

The authors sought to better understand the combined effects of pretransplant, transplant, and post-transplant factors in determining risks of serious cardiovascular disease after hematopoietic cell transplantation (HCT). Hospitalizations and deaths associated with serious cardiovascular outcomes were identified among 1379 Washington State residents who received HCT (57% allogeneic and 43% autologous) at a single center from 1985 to 2005, survived ≥ 2 years, and followed through 2008. Using a nested case-cohort design, relationships (hazard ratios [HRs]) between potential risk factors and outcomes were examined among affected survivors and a randomly selected subcohort (N = 509). After 7.0 years of median follow-up (range, 2.0 to 23.7), the 10-year cumulative incidence of ischemic heart disease, cardiomyopathy, stroke, and all-cause cardiovascular death was 3.8%, 6.0%, 3.5%, and 3.7%, respectively. In multivariable analysis, increased pretransplant anthracycline was associated with cardiomyopathy. Active chronic graft-versus-host disease was associated with cardiovascular death (HR, 4.0; 95% confidence interval, 1.1 to 14.7); risk was otherwise similar between autologous versus allogeneic HCT recipients. Independent of therapeutic exposures, pretransplant smoking, hypertension, dyslipidemia, diabetes, and obesity conferred additional risk of all outcomes except stroke (HR ≥ 1.5 for each additional risk factor, P < .03). Hypertension and dyslipidemia at 1 year with persistence of these conditions 2 or more years after HCT also were associated with independent risks of multiple outcomes. HCT survivors with preexisting or newly developed and persistent cardiovascular risk factors remain at greater risk of subsequent serious cardiovascular disease compared with other survivors, independent of chemo- and radiotherapy exposures. These survivors should receive appropriate follow-up and be considered for primary intervention.

Trends in prevalence and control of diabetes in the United States, 1988-1994 and 1999-2010

BACKGROUND

Trends in the prevalence and control of diabetes defined by hemoglobin A1c (HbA1c) levels are important for health care policy and planning.

OBJECTIVE

To update trends in the prevalence of diabetes, prediabetes, and glycemic control.

DESIGN

Cross-sectional.

SETTING

NHANES (National Health and Nutrition Examination Survey) in 1988-1994 and 1999-2010.

PARTICIPANTS

Adults aged 20 years or older.

MEASUREMENTS

We used calibrated HbA1c levels to define undiagnosed diabetes (≥6.5%); prediabetes (5.7% to 6.4%); and, among persons with diagnosed diabetes, glycemic control (<7.0% or <8.0%). Trends in HbA1c categories were compared with fasting glucose levels (≥7.0 mmol/L [≥126 mg/dL] and 5.6 to 6.9 mmol/L [100 to 125 mg/dL]).

RESULTS

In 2010, approximately 21 million U.S. adults aged 20 years or older had total confirmed diabetes (self-reported diabetes or diagnostic levels for both fasting glucose and calibrated HbA1c). During 2 decades, the prevalence of total confirmed diabetes increased, but the prevalence of undiagnosed diabetes remained fairly stable, reducing the proportion of total diabetes cases that are undiagnosed to 11% in 2005-2010. The prevalence of prediabetes was lower when defined by calibrated HbA1c levels than when defined by fasting glucose levels but has increased from 5.8% in 1988-1994 to 12.4% in 2005-2010 when defined by HbA1c levels. Glycemic control improved overall, but total diabetes prevalence was greater and diabetes was less controlled among non-Hispanic blacks and Mexican Americans compared with non-Hispanic whites.

LIMITATION

Cross-sectional design.

CONCLUSION

Over the past 2 decades, the prevalence of total diabetes has increased substantially. However, the proportion of undiagnosed diabetes cases decreased, suggesting improvements in screening and diagnosis. Among the growing number of persons with diagnosed diabetes, glycemic control improved but remains a challenge, particularly among non-Hispanic blacks and Mexican Americans.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Increased prevalence of diabetes in Argentina is due to easier health care access rather than to an actual increase in prevalence

Introduction

According to the Argentine National Risk Factor Survey (ANRFS), between 2005 and 2009, self-reported Diabetes increased in Argentina from 8.4% to 9.6%, accompanied by a raise in the prevalence of obesity and low physical activity. In the same period, it also increased blood sugar checks from 69.3% to 75.7%. Since surveillance data in Argentina rely on self-reports, the estimated prevalence of diabetes may be affected by an increase in the proportion of subjects with access to preventive services. We evaluated the independent effect of a recent blood sugar check, on the increase in self-reported diagnoses of diabetes between 2005 and 2009.

Materials and Methods

A secondary analysis of data from the 2005 and 2009 ANRFS was performed. Diabetes was defined as having been diagnosed Diabetes or high blood sugar by a health professional, obesity was calculated as BMI≥30 kg/m², based on self-reported height and weight and physical activity was measured using the International Physical Activity Questionnaire. We used logistic regression models to explore the relationship between prevalence of self-reported diabetes and recent blood sugar check as the main predictor.

Results

The prevalence of diabetes rose from 8.4% to 9.6%; obesity from 14.5% to 18% and low physical activity from 46.2% to 55%, between 2005 and 2009. Among those who recently checked their blood sugar no differences were found in the prevalence of diabetes: 13% in 2005 vs. 13.2% in 2009. Findings of the multivariable analysis showed that obesity and low physical activity were significantly associated with self reported diabetes in the adjusted model (OR = 1.80 for obesity, and OR = 1.12 for low physical activity but the strongest predictor was recent blood sugar check (OR = 4.75).

Discussion

An increased prevalence of self-reported diabetes between 2005 and 2009 might indicate an improvement in the access to preventive services rather than a positive increase in the prevalence of diabetes.

Association of functional decline with subsequent diabetes incidence in U.S. adults aged 51 years and older: the Health and Retirement Study 1998-2010

OBJECTIVE We assessed whether functional decline and physical disability increase the subsequent risk of diabetes. RESEARCH DESIGN AND METHODS We used a subsample of adults aged 51 years and older with no diabetes at baseline who were followed up to 12 years (1998-2010) in the Health and Retirement Study, an observational study of a nationally representative survey. We assessed baseline disability status and incident disability with subsequent risk of diabetes, accounting for death as a competing risk and controlling for BMI, age, sex, race/ethnicity, net wealth, mother's level of education, respondents' level of education, and time of follow-up. Disability was defined as none, mild, moderate, and severe, based on a validated scale of mobility measures. Diabetes was identified by self-report of a diagnosis from a doctor. Population attributable fraction (PAF) was calculated to assess the percentage of diabetes cases that were attributable to mobility disability. RESULTS The sample included 22,878 adults with an average of 8.7 years of follow-up; 9,649 (41.2%) reported some level of disability at baseline, and 8,175 (35.7%) additional participants developed disability during follow-up; 3,546 (15.5%) participants developed diabetes; and 5,869 (25.6%) died. Regression analyses found a statistically significant dose-response relationship of increased risk of diabetes (28-95%) among those with any level of functional decline, prevalent or incident. Among the subanalytic sample, including incident disability only, the PAF was 6.9% (CI 4.2-9.5). CONCLUSIONS Our findings suggest those who become disabled, even mildly, are at increased risk of developing diabetes. This finding raises the possibility that approaches to prevent disability in older adults could also reduce diabetes incidence.

Gestational diabetes mellitus in Far North Queensland, Australia, 2004 to 2010: midwives' perinatal data most accurate source

OBJECTIVES

This study examines the accuracy of Gestational Diabetes Mellitus (GDM) case-ascertainment in routinely collected data.

METHODS

Retrospective cohort study analysed routinely collected data from all births at Cairns Base Hospital, Australia, from 1 January 2004 to 31 December 2010 in the Cairns Base Hospital Clinical Coding system (CBHCC) and the Queensland Perinatal Data Collection (QPDC). GDM case ascertainment in the National Diabetes Services Scheme (NDSS) and Cairns Diabetes Centre (CDC) data were compared.

RESULTS

From 2004 to 2010, the specificity of GDM case-ascertainment in the QPDC was 99%. In 2010, only 2 of 225 additional cases were identified from the CDC and CBHCC, suggesting QPDC sensitivity is also over 99%. In comparison, the sensitivity of the CBHCC data was 80% during 2004-2010. The sensitivity of CDC data was 74% in 2010. During 2010, 223 births were coded as GDM in the QPDC, and the NDSS registered 247 women with GDM from the same postcodes, suggesting reasonable uptake on the NDSS register. However, the proportion of Aboriginal and Torres Strait Islander women was lower than expected.

CONCLUSION

The accuracy of GDM case-ascertainment in the QPDC appears high, with lower accuracy in routinely collected hospital and local health service data. This limits capacity of local data for planning and evaluation, and developing structured systems to improve post-pregnancy care, and may underestimate resources required.

IMPLICATIONS

Data linkage should be considered to improve accuracy of routinely collected local health service data. The accuracy of the NDSS for Aboriginal and Torres Strait Islander women requires further evaluation.

Systematic review and meta-analysis of validation studies on a diabetes case definition from health administrative records

OBJECTIVES

Health administrative data are frequently used for diabetes surveillance. We aimed to determine the sensitivity and specificity of a commonly-used diabetes case definition (two physician claims or one hospital discharge abstract record within a two-year period) and their potential effect on prevalence estimation.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched Medline (from 1950) and Embase (from 1980) databases for validation studies through August 2012 (keywords: "diabetes mellitus"; "administrative databases"; "validation studies"). Reviewers abstracted data with standardized forms and assessed quality using Quality Assessment of Diagnostic Accuracy Studies (QUADAS) criteria. A generalized linear model approach to random-effects bivariate regression meta-analysis was used to pool sensitivity and specificity estimates. We applied correction factors derived from pooled sensitivity and specificity estimates to prevalence estimates from national surveillance reports and projected prevalence estimates over 10 years (to 2018).

RESULTS

The search strategy identified 1423 abstracts among which 11 studies were deemed relevant and reviewed; 6 of these reported sensitivity and specificity allowing pooling in a meta-analysis. Compared to surveys or medical records, sensitivity was 82.3% (95%CI 75.8, 87.4) and specificity was 97.9% (95%CI 96.5, 98.8). The diabetes case definition underestimated prevalence when it was ≤10.6% and overestimated prevalence otherwise.

CONCLUSION

The diabetes case definition examined misses up to one fifth of diabetes cases and wrongly identifies diabetes in approximately 2% of the population. This may be sufficiently sensitive and specific for surveillance purposes, in particular monitoring prevalence trends. Applying correction factors to adjust prevalence estimates from this definition may be helpful to increase accuracy of estimates.

Estimating the population prevalence of diagnosed and undiagnosed diabetes

OBJECTIVE

Health administrative data are frequently used for diabetes surveillance, but validation studies are limited, and undiagnosed diabetes has not been considered in previous studies. We compared the test properties of an administrative definition with self-reported diabetes and estimated prevalence of undiagnosed diabetes by measuring glucose levels in mailed-in capillary blood samples.

RESEARCH DESIGN AND METHODS

A stratified random sample of 6,247 individuals (Quebec province) was surveyed by telephone and asked to mail in fasting blood samples on filter paper to a central laboratory. An administrative definition was applied (two physician claims or one hospitalization for diabetes within a 2-year period) and compared with self-reported diabetes alone and with self-reported diabetes or elevated blood glucose level (≥7 mmol/L). Population-level prevalence was estimated with the use of the administrative definition corrected for its sensitivity and specificity.

RESULTS

Compared with self-reported diabetes, sensitivity and specificity were 84.3% (95% CI 79.3-88.5%) and 97.9% (97.4-98.4%), respectively. Compared with diabetes by self-report and/or glucose testing, sensitivity was lower at 58.2% (52.2-64.6%), whereas specificity was similar at 98.7% (98.0-99.3%). Adjusted for sampling weights, population-level prevalence of physician-diagnosed diabetes was 7.2% (6.3-8.0%). Prevalence of total diabetes (physician-diagnosed and undiagnosed) was 13.4% (11.7-15.0%), indicating that ∼40% of diabetes cases are undiagnosed.

CONCLUSIONS

A substantial proportion of diabetes cases are missed by surveillance methods that use health administrative databases. This finding is concerning because individuals with undiagnosed diabetes are likely to have a delay in treatment and, thus, a higher risk for diabetes-related complications.

Sleep characteristics, mental health, and diabetes risk: a prospective study of U.S. military service members in the Millennium Cohort Study

OBJECTIVE

Research has suggested that a higher risk of type 2 diabetes associated with sleep characteristics exists. However, studies have not thoroughly assessed the potential confounding effects of mental health conditions associated with alterations in sleep.

RESEARCH DESIGN AND METHODS

We prospectively assessed the association between sleep characteristics and self-reported incident diabetes among Millennium Cohort Study participants prospectively followed over a 6-year time period. Surveys are administered approximately every 3 years and collect self-reported data on demographics, height, weight, lifestyle, features of military service, sleep, clinician-diagnosed diabetes, and mental health conditions assessed by the PRIME-MD Patient Health Questionnaire and the PTSD Checklist-Civilian Version. Statistical methods for longitudinal data were used for data analysis.

RESULTS

We studied 47,093 participants (mean 34.9 years of age; mean BMI 26.0 kg/m2; 25.6% female). During 6 years of follow-up, 871 incident diabetes cases occurred (annual incidence 3.6/1,000 person-years). In univariate analyses, incident diabetes was significantly more likely among participants with self-reported trouble sleeping, sleep duration<6 h, and sleep apnea. Participants reporting incident diabetes were also significantly older, of nonwhite race, of higher BMI, less likely to have been deployed, and more likely to have reported baseline symptoms of panic, anxiety, posttraumatic stress disorder, and depression. After adjusting for covariates, trouble sleeping (odds ratio 1.21 [95% CI 1.03-1.42]) and sleep apnea (1.78 [1.39-2.28]) were significantly and independently related to incident diabetes.

CONCLUSIONS

Trouble sleeping and sleep apnea predict diabetes risk independent of mental health conditions and other diabetes risk factors.

Concordance between administrative health data and medical records for diabetes status in coronary heart disease patients: a retrospective linked data study

BACKGROUND

Administrative data are a valuable source of estimates of diabetes prevalence for groups such as coronary heart disease (CHD) patients. The primary aim of this study was to measure concordance between medical records and linked administrative health data for recording diabetes in CHD patients, and to assess temporal differences in concordance. Secondary aims were to determine the optimal lookback period for identifying diabetes in this patient group, whether concordance differed for Indigenous people, and to identify predictors of false positives and negatives in administrative data.

METHODS

A population representative sample of 3943 CHD patients hospitalized in Western Australia in 1998 and 2002-04 were selected, and designated according to the International Classification of Diseases (ICD) version in use at the time (ICD-9 and ICD-10 respectively). Crude prevalence and concordance were compared for the two samples. Concordance measures were estimated from administrative data comparing diabetes status recorded on the selected CHD admission ('index admission') and on any hospitalization in the previous 1, 2, 5, 10 or 15 years, against hospital medical records. Potential modifiers of agreement were determined using chi-square tests and multivariable logistic regression models.

RESULTS

Identification of diabetes on the index CHD admission was underestimated more in the ICD-10 than ICD-9 sample (sensitivity 81.5% versus 91.1%, underestimation 15.1% versus 4.4% respectively). Sensitivity increased to 89.6% in the ICD-10 period using at least 10 years of hospitalization history. Sensitivity was higher and specificity lower in Indigenous patients, and followed a similar pattern of improving concordance with increasing lookback period. Characteristics associated with false negatives for diabetes on the index CHD hospital admission were elective admission, in-hospital death, principal diagnosis, and in the ICD-10 period only, fewer recorded comorbidities.

CONCLUSIONS

The accuracy of identifying diabetes status in CHD patients is improved in linked administrative health data by using at least 10 years of hospitalization history. Use of this method would reduce bias when measuring temporal trends in diabetes prevalence in this patient group. Concordance measures are as reliable in Indigenous as non-Indigenous patients.

Long-term fine particulate matter exposure and mortality from diabetes in Canada

OBJECTIVE

Recent studies suggest that chronic exposure to air pollution can promote the development of diabetes. However, whether this relationship actually translates into an increased risk of mortality attributable to diabetes is uncertain.

RESEARCH DESIGN AND METHODS

We evaluated the association between long-term exposure to ambient fine particulate matter (PM2.5) and diabetes-related mortality in a prospective cohort analysis of 2.1 million adults from the 1991 Canadian census mortality follow-up study. Mortality information, including ∼5,200 deaths coded as diabetes being the underlying cause, was ascertained by linkage to the Canadian Mortality Database from 1991 to 2001. Subject-level estimates of long-term exposure to PM2.5 were derived from satellite observations. The hazard ratios (HRs) for diabetes-related mortality were related to PM2.5 and adjusted for individual-level and contextual variables using Cox proportional hazards survival models.

RESULTS

Mean PM2.5 exposure levels for the entire population were low (8.7 µg/m3; SD, 3.9 µg/m3; interquartile range, 6.2 µg/m3). In fully adjusted models, a 10-µg/m3 elevation in PM2.5 exposure was associated with an increase in risk for diabetes-related mortality (HR, 1.49; 95% CI, 1.37-1.62). The monotonic change in risk to the population persisted to PM2.5 concentration<5 µg/m3.

CONCLUSIONS

Long-term exposure to PM2.5, even at low levels, is related to an increased risk of mortality attributable to diabetes. These findings have considerable public health importance given the billions of people exposed to air pollution and the worldwide growing epidemic of diabetes.

Secular changes in the age-specific prevalence of diabetes among U.S. adults: 1988-2010

OBJECTIVE

To examine the age-specific changes of prevalence of diabetes among U.S. adults during the past 2 decades.

RESEARCH DESIGN AND METHODS

This study included 22,586 adults sampled in three periods of the National Health and Nutrition Examination Survey (1988-1994, 1999-2004, and 2005-2010). Diabetes was defined as having self-reported diagnosed diabetes or having a fasting plasma glucose level ≥ 126 mg/dL or HbA1c ≥ 6.5% (48 mmol/mol).

RESULTS

The number of adults with diabetes increased by 75% from 1988-1994 to 2005-2010. After adjusting for sex, race/ethnicity, and education level, the prevalence of diabetes increased over the two decades across all age-groups. Younger adults (20-34 years of age) had the lowest absolute increase in diabetes prevalence of 1.0%, followed by middle-aged adults (35-64) at 2.7% and older adults (≥ 65) at 10.0% (all P < 0.001). Comparing 2005-2010 with 1988-1994, the adjusted prevalence ratios (PRs) by age-group were 2.3, 1.3, and 1.5 for younger, middle-aged, and older adults, respectively (all P < 0.05). After additional adjustment for body mass index (BMI), waist-to-height ratio (WHtR), or waist circumference (WC), the adjusted PR remained statistically significant only for adults ≥ 65 years of age.

CONCLUSIONS

During the past two decades, the prevalence of diabetes increased across all age-groups, but adults ≥ 65 years of age experienced the largest increase in absolute change. Obesity, as measured by BMI, WHtR, or WC, was strongly associated with the increase in diabetes prevalence, especially in adults <65.

Identifying patients with diabetes and the earliest date of diagnosis in real time: an electronic health record case-finding algorithm

BACKGROUND

Effective population management of patients with diabetes requires timely recognition. Current case-finding algorithms can accurately detect patients with diabetes, but lack real-time identification. We sought to develop and validate an automated, real-time diabetes case-finding algorithm to identify patients with diabetes at the earliest possible date.

METHODS

The source population included 160,872 unique patients from a large public hospital system between January 2009 and April 2011. A diabetes case-finding algorithm was iteratively derived using chart review and subsequently validated (n = 343) in a stratified random sample of patients, using data extracted from the electronic health records (EHR). A point-based algorithm using encounter diagnoses, clinical history, pharmacy data, and laboratory results was used to identify diabetes cases. The date when accumulated points reached a specified threshold equated to the diagnosis date. Physician chart review served as the gold standard.

RESULTS

The electronic model had a sensitivity of 97%, specificity of 90%, positive predictive value of 90%, and negative predictive value of 96% for the identification of patients with diabetes. The kappa score for agreement between the model and physician for the diagnosis date allowing for a 3-month delay was 0.97, where 78.4% of cases had exact agreement on the precise date.

CONCLUSIONS

A diabetes case-finding algorithm using data exclusively extracted from a comprehensive EHR can accurately identify patients with diabetes at the earliest possible date within a healthcare system. The real-time capability may enable proactive disease management.

Prevalence and comorbidities of known diabetes in northeastern Italy

AIMS/INTRODUCTION

We aimed at estimating the prevalence and at identifying the frequent comorbidities of diabetes mellitus in a region of northeastern Italy from administrative health data.

MATERIALS AND METHODS

The prevalence was estimated according to two disease definitions, based on administrative health data. Association rule mining was used to detect comorbid diagnoses that coexisted with a diagnosis of diabetes among patients admitted to the regional hospitals.

RESULTS

The prevalence of known diabetes in 2010 was 6.0-8.1%, with great variations by age class (from approximately 2% <60 years to more than 20% in some elderly age groups). Of 155,494 patients admitted to the hospital in 2011, 9,358 had a diagnosis of diabetes. A total of 12 rules satisfied our criteria for support (>0.5%) and confidence (>5%), and identified nine frequent isolated comorbidities and three pairs of comorbid diagnoses. The rule with the highest support (2.4%) and confidence (39.5%) identified the combination of diabetes and essential hypertension.

CONCLUSIONS

Association rule mining was useful, because it showed the complexity of diabetic patients. Clinical management of those patients cannot neglect comorbidities.

Cardiovascular disease risk factors among women veterans at VA medical facilities

BACKGROUND

Hypertension, hyperlipidemia, diabetes, and obesity in middle adulthood each elevate the long-term risk of cardiovascular disease (CVD). The prevalence of these conditions among women veterans is incompletely described.

OBJECTIVE

To describe the prevalence of CVD risk factors among women veterans in middle adulthood.

DESIGN

Serial cross-sectional studies of data from the Diabetes Epidemiologic Cohorts (DEpiC), a national, longitudinal data set including information on all patients in the Veterans Health Administration (VA).

PARTICIPANTS

Women veterans (n = 255,891) and men veterans (n = 2,271,605) aged 35-64 receiving VA care in fiscal year (FY) 2010.

MAIN MEASURES

Prevalence of CVD risk factors in FY2010 by age and, for those aged 45-54 years, by race, region, period of military service, priority status, and mental illness or substance abuse; prevalence by year from 2000 to 2010 in women veterans receiving VA care in both 2000 and 2010 who were free of the factor in 2000.

KEY RESULTS

Hypertension, hyperlipidemia, and diabetes were common among women and men, although more so among men. Hypertension was present in 13 % of women aged 35-44 years, 28 % of women aged 45-54, and 42 % of women aged 55-64. Hyperlipidemia prevalence was similar. Diabetes affected 4 % of women aged 35-44, and increased more than four-fold in prevalence to 18 % by age 55-64. The prevalence of obesity increased from 14 % to 18 % with age among women and was similarly prevalent in men. The relative rate of having two or more CVD risk factors in women compared to men increased progressively with age, from 0.55 (35-44 years) to 0.71 (45-54) to 0.73 (55-64). Most of the women with a factor present in 2010 were first diagnosed with the condition in the 10 years between 2000 and 2010.

CONCLUSIONS

CVD risk factors are common among women veterans aged 35-64. Future research should investigate which interventions would most effectively reduce risk in this population.

Accuracy of heart disease prevalence estimated from claims data compared with an electronic health record

Introduction

We developed a decision support tool that can guide the development of heart disease prevention programs to focus on the interventions that have the most potential to benefit populations. To use it, however, users need to know the prevalence of heart disease in the population that they wish to help. We sought to determine the accuracy with which the prevalence of heart disease can be estimated from health care claims data.

Methods

We compared estimates of disease prevalence based on insurance claims to estimates derived from manual health records in a stratified random sample of 480 patients aged 30 years or older who were enrolled at any time from August 1, 2007, through July 31, 2008 (N = 474,089) in HealthPartners insurance and had a HealthPartners Medical Group electronic record. We compared randomly selected development and validation samples to a subsample that was also enrolled on August 1, 2005 (n = 272,348). We also compared the records of patients who had a gap in enrollment of more than 31 days with those who did not, and compared patients who had no visits, only 1 visit, or 2 or more visits more than 31 days apart for heart disease.

Results

Agreement between claims data and manual review was best in both the development and the validation samples (Cohen’s κ, 0.92, 95% confidence interval [CI], 0.87–0.97; and Cohen’s κ, 0.94, 95% CI, 0.89–0.98, respectively) when patients with only 1 visit were considered to have heart disease.

Conclusion

In this population, prevalence of heart disease can be estimated from claims data with acceptable accuracy.

Work Limitations and Their Relationship to Morbidity Burden among Academic Health Center Employees with Diabetes

The objective of this study was to determine the prevalence of work limitations and their relationship to morbidity burden among academic health center employees with diabetes. Employees with diabetes were surveyed via Internet and mail using the Work Limitations Questionnaire. Morbidity burden was measured using the Adjusted Clinical Groups methodology. Seventy-two percent of the employees with diabetes had a work limitation. Adjusted odds ratios for overall, physical, time, and output limitations were 1.81, 2.27, 2.13, and 2.14, respectively. Morbidity burden level is an indicator of work limitations in employees with diabetes and can be used to identify employees who may benefit from specialized services aimed at addressing their work limitations associated with diabetes.

Diabetes and asthma case identification, validation, and representativeness when using electronic health data to construct registries for comparative effectiveness and epidemiologic research

BACKGROUND

Advances in health information technology and widespread use of electronic health data offer new opportunities for development of large scale multisite disease-specific patient registries. Such registries use existing data, can be constructed at relatively low cost, include large numbers of patients, and once created can be used to address many issues with a short time between posing a question and obtaining an answer. Potential applications include comparative effectiveness research, public health surveillance, mapping and improving quality of clinical care, and others.

OBJECTIVE AND DISCUSSION

This paper describes selected conceptual and practical challenges related to development of multisite diabetes and asthma registries, including development of case definitions, validation of case identification methods, variation in electronic health data sources; representativeness of registry populations, including the impact of attrition. Specific challenges are illustrated with data from actual registries.

Towards automatic diabetes case detection and ABCS protocol compliance assessment

OBJECTIVE

According to the American Diabetes Association, the implementation of the standards of care for diabetes has been suboptimal in most clinical settings. Diabetes is a disease that had a total estimated cost of $174 billion in 2007 for an estimated diabetes-affected population of 17.5 million in the United States. With the advent of electronic medical records (EMR), tools to analyze data residing in the EMR for healthcare surveillance can help reduce the burdens experienced today. This study was primarily designed to evaluate the efficacy of employing clinical natural language processing to analyze discharge summaries for evidence indicating a presence of diabetes, as well as to assess diabetes protocol compliance and high risk factors.

METHODS

Three sets of algorithms were developed to analyze discharge summaries for: (1) identification of diabetes, (2) protocol compliance, and (3) identification of high risk factors. The algorithms utilize a common natural language processing framework that extracts relevant discourse evidence from the medical text. Evidence utilized in one or more of the algorithms include assertion of the disease and associated findings in medical text, as well as numerical clinical measurements and prescribed medications.

RESULTS

The diabetes classifier was successful at classifying reports for the presence and absence of diabetes. Evaluated against 444 discharge summaries, the classifier's performance included macro and micro F-scores of 0.9698 and 0.9865, respectively. Furthermore, the protocol compliance and high risk factor classifiers showed promising results, with most F-measures exceeding 0.9.

CONCLUSIONS

The presented approach accurately identified diabetes in medical discharge summaries and showed promise with regards to assessment of protocol compliance and high risk factors. Utilizing free-text analytic techniques on medical text can complement clinical-public health decision support by identifying cases and high risk factors.

Prevalence of diagnosed arthritis and arthritis-attributable activity limitation among adults with and without diagnosed diabetes: United States, 2008-2010

OBJECTIVE

To estimate the prevalence of diagnosed arthritis among U.S. adults and the proportion of arthritis-attributable activity limitation (AAAL) among those with arthritis by diagnosed diabetes mellitus (DM) status.

RESEARCH DESIGN AND METHODS

We estimated prevalences and their ratios using 2008-2010 U.S. National Health Interview Survey of noninstitutionalized U.S. adults aged ≥ 18 years. Respondents' arthritis and DM status were both based on whether they reported a diagnosis of these diseases. Other characteristics used for stratification or adjustment included age, sex, race/ethnicity, education level, BMI, and physical activity level.

RESULTS

Among adults with DM, the unadjusted prevalences of arthritis and proportion of AAAL among adults with arthritis (national estimated cases in parentheses) were 48.1% (9.6 million) and 55.0% (5.3 million), respectively. After adjusting for other characteristics, the prevalence ratios of arthritis and of AAAL among arthritic adults with versus without DM (95% CI) were 1.44 (1.35-1.52) and 1.21 (1.15-1.28), respectively. The prevalence of arthritis increased with age and BMI and was higher for women, non-Hispanic whites, and inactive adults compared with their counterparts both among adults with and without DM (all P values < 0.05). Among adults with diagnosed DM and arthritis, the proportion of AAAL was associated with being obese, but was not significantly associated with age, sex, and race/ethnicity.

CONCLUSIONS

Among U.S. adults with diagnosed DM, nearly half also have diagnosed arthritis; moreover, more than half of those with both diseases had AAAL. Arthritis can be a barrier to physical activity among adults with diagnosed DM.

Eight-year trends of cardiometabolic morbidity and mortality in patients with schizophrenia

OBJECTIVE

We examined cardiometabolic disease and mortality over 8 years among individuals with and without schizophrenia.

METHOD

We compared 65,362 patients in the Veteran Affairs (VA) health system with schizophrenia to 65,362 VA patients without serious mental illness (non-SMI) matched on age, service access year and location. The annual prevalence of diagnosed cardiovascular disease, diabetes, dyslipidemia, hypertension, obesity, and all-cause and cause-specific mortality was compared for fiscal years 2000-2007. Mean years of potential life lost (YPLLs) were calculated annually.

RESULTS

The cohort was mostly male (88%) with a mean age of 54 years. Cardiometabolic disease prevalence increased in both groups, with non-SMI patients having higher disease prevalence in most years. Annual between-group differences ranged from <1% to 6%. Annual mortality was stable over time for schizophrenia (3.1%) and non-SMI patients (2.6%). Annual mean YPLLs increased from 12.8 to 15.4 in schizophrenia and from 11.8 to 14.0 for non-SMI groups.

CONCLUSIONS

VA patients with and without schizophrenia show increasing but similar prevalence rates of cardiometabolic diseases. YPLLs were high in both groups and only slightly higher among patients with schizophrenia. The findings highlight the complex population served by the VA while suggesting a smaller mortality impact from schizophrenia than previously reported.

Construction of a multisite DataLink using electronic health records for the identification, surveillance, prevention, and management of diabetes mellitus: the SUPREME-DM project

Introduction

Electronic health record (EHR) data enhance opportunities for conducting surveillance of diabetes. The objective of this study was to identify the number of people with diabetes from a diabetes DataLink developed as part of the SUPREME-DM (SUrveillance, PREvention, and ManagEment of Diabetes Mellitus) project, a consortium of 11 integrated health systems that use comprehensive EHR data for research.

Methods

We identified all members of 11 health care systems who had any enrollment from January 2005 through December 2009. For these members, we searched inpatient and outpatient diagnosis codes, laboratory test results, and pharmaceutical dispensings from January 2000 through December 2009 to create indicator variables that could potentially identify a person with diabetes. Using this information, we estimated the number of people with diabetes and among them, the number of incident cases, defined as indication of diabetes after at least 2 years of continuous health system enrollment.

Results

The 11 health systems contributed 15,765,529 unique members, of whom 1,085,947 (6.9%) met 1 or more study criteria for diabetes. The nonstandardized proportion meeting study criteria for diabetes ranged from 4.2% to 12.4% across sites. Most members with diabetes (88%) met multiple criteria. Of the members with diabetes, 428,349 (39.4%) were incident cases.

Conclusion

The SUPREME-DM DataLink is a unique resource that provides an opportunity to conduct comparative effectiveness research, epidemiologic surveillance including longitudinal analyses, and population-based care management studies of people with diabetes. It also provides a useful data source for pragmatic clinical trials of prevention or treatment interventions.

Simulated value-based insurance design applied to statin use by Medicare beneficiaries with diabetes

OBJECTIVE

To examine cost responsiveness and total costs associated with a simulated "value-based" insurance design for statin therapy in a Medicare population with diabetes.

METHODS

Four-year panels were constructed from the 1997-2005 Medicare Current Beneficiary Survey selected by self-report or claims-based diagnoses of diabetes in year 1 and use of statins in year 2 (N = 899). We computed the number of 30-day statin prescription fills, out-of-pocket and third-party drug costs, and Medicare Part A and Part B spending. Multivariate ordinary least squares regression models predicted statin fills as a function of out-of-pocket costs, and a generalized linear model with log link predicted Medicare spending as a function of number of fills, controlling for baseline characteristics. Estimated coefficients were used to simulate changes in fills associated with co-payment caps from $25 to $1 and to compute changes in third-party payments and Medicare cost offsets associated with incremental fills. Analyses were stratified by patient cardiovascular event risk.

RESULTS

A simulated out-of-pocket price of $25 [$1] increased plan drug spending by $340 [$794] and generated Medicare Part A/B savings of $262 [$531]; savings for high-risk patients were $558 [$1193], generating a net saving of $249 [$415].

CONCLUSIONS

Reducing statin co-payments for Medicare beneficiaries with diabetes resulted in modestly increased use and reduced medical spending. The value-based insurance design simulation strategy met financial feasibility criteria but only for higher-risk patients.

Various adiposity measures show similar positive associations with type 2 diabetes in Caucasians, native Hawaiians, and Japanese Americans: the multiethnic cohort

The authors evaluated the association of body mass index (BMI), waist circumference (WC) and hip circumference (HC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR) with diabetes in Caucasians, Native Hawaiians, and Japanese Americans aged 45 to 75 years in the Multiethnic Cohort. Diabetes cases were obtained from self-reports and by linkages with health insurance plans. The authors estimated adjusted prevalence odds ratios (PORs) and compared the area under the receiver operating characteristic curves (AUC). All measures were positively associated with diabetes prevalence; the PORs were 1.25 to 1.64 in men and 1.52 to 1.83 in women. In all 3 ethnic groups, the AUCs in men were greater for BMI than for the other measures, whereas in women, the AUCs were greater for combined models than for BMI alone, but the differences were small and not clinically significant. It does not appear that one anthropometric measure best reflects diabetes prevalence or performs better in one ethnic group than in another.

The reliability of hospital and pharmaceutical data to assess prevalent cases of chronic obstructive pulmonary disease

Identifying chronic obstructive disease (COPD) cases is required to estimate COPD prevalence, to enroll COPD cohorts and to estimate air pollution health effects. Administrative health data are frequently used to identify COPD cases, though their validity has not been satisfactorily assessed. This paper aims to assess the contribution of pharmaceutical data in detecting COPD cases and to estimate the reliability of hospital/mortality databases in detecting COPD cases. Prevalent COPD cases among 35-plus-year-olds were estimated in four Italian areas in 2006 from hospital/mortality registries and adding pharmaceutical data. Age-specific and age-standardized prevalence rates were calculated in each area. Internal validity of COPD diagnoses from hospital and mortality databases was assessed. Pharmaceutical database was used to confirm the hospital/mortality COPD cases and to examine the selection and misclassification of hospitalized cases. Possible misclassification between COPD and asthma cases was estimated using hospital data. Prevalent COPD cases were 77,098 from hospital/mortality registries, 172,357 when respiratory prescriptions were added. Prevalence ranged from 4.0%-6.7%. Only 22.7% of pharmaceutical COPD cases were hospitalized or died and only 37.2% of hospital/mortality cases consumed respiratory medicines; this last proportion increased to 64.5% among the older cases with a principal diagnosis. COPD cases with a contemporary asthma diagnosis were 3.1%. We found that pharmaceutical data increases COPD prevalence estimates 2.2-2.5 times. Hospitalization does not necessarily indicate COPD severity, COPD as a principal diagnosis confirmed with medicine prescription more likely represented true cases. Misclassification affects asthma cases to greater extent than COPD cases.

Lack of periconceptional vitamins or supplements that contain folic acid and diabetes mellitus-associated birth defects

OBJECTIVE

The purpose of this study was to examine the risk of birth defects in relation to diabetes mellitus and the lack of use of periconceptional vitamins or supplements that contain folic acid.

STUDY DESIGN

The National Birth Defects Prevention Study (1997-2004) is a multicenter, population-based case-control study of birth defects (14,721 cases and 5437 control infants). Cases were categorized into 18 types of heart defects and 26 noncardiac birth defects. We estimated odds ratios for independent and joint effects of preexisting diabetes mellitus and a lack of periconceptional use of vitamins or supplements that contain folic acid.

RESULTS

The pattern of odds ratios suggested an increased risk of defects that are associated with diabetes mellitus in the absence vs the presence of the periconceptional use of vitamins or supplements that contain folic acid.

CONCLUSION

The lack of periconceptional use of vitamins or supplements that contain folic acid may be associated with an excess risk for birth defects due to diabetes mellitus.

Prevalence, incidence and mortality of diagnosed diabetes: evidence from an Italian population-based study

AIMS

To describe trends in diagnosed diabetes prevalence, incidence and mortality from 2000 to 2007 in the most heavily populated Italian region.

METHODS

We examined the prevalence and incidence rates of Type 1 and Type 2 diabetes and yearly mortality rates among individuals with diabetes from 2000 to 2007 using an administrative health database of prescription, disease-specific exemption and hospitalization records of more than 9 million inhabitants of Lombardy. Age- and sex-specific rates were calculated and temporal trends for subjects aged ≥ 30 years were analysed.

RESULTS

The crude point diabetes prevalence rose from 3.0% in 2000 to 4.2% in 2007, a 40% increase. The incidence remained stable during the study period with a rate of 4/1000 per year. Overall mortality declined from 43.2/1000 in 2001 to 40.3/1000 in 2007 (6.7% decrease) at a rate slightly higher than that of the general population (4.8% decrease). Our projection in subjects aged ≥ 30 years indicates that the prevalence will rise continuously over the next years, reaching 11.1% in 2030.

CONCLUSIONS

The prevalence of diabetes increased substantially between 2000 and 2007, mainly because there are more patients with a new diagnosis each year than those who die. The increase observed by 2007 almost reached the World Health Organization prediction for 2030. Our analyses suggest that the increase will continue over the next few decades. These data are important for defining the burden of diabetes in the near future, to help in planning health services and ensure proper allocation of resources.

Vaccination and risk of type 1 diabetes mellitus in active component U.S. Military, 2002-2008

AIMS/HYPOTHESIS

To evaluate whether vaccination increases the risk of type 1 diabetes mellitus in active component U.S. military personnel.

METHODS

We conducted a retrospective cohort study among active component U.S. military personnel age 17-35 years. Individuals with first time diagnoses of type 1 diabetes between January 1, 2002 and December 31, 2008 were identified using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. We used Poisson regression to estimate risk ratios between individual vaccine exposures and type 1 diabetes. Secondary analyses were performed controlling for receipt of multiple vaccines and available demographic variables.

RESULTS

Our study population consisted of 2,385,102 individuals followed for approximately 7,644,098 person-years of service. This included 1074 incident type 1 diabetes cases. We observed no significant increased risk of type 1 diabetes after vaccination with anthrax vaccine adsorbed (AVA) [RR=1.00; 95% CI (0.85, 1.17)], smallpox vaccine [RR=0.84; 95% (CI 0.70, 1.01)], typhoid vaccine [RR=1.03; 95% CI (0.87, 1.22)], hepatitis B vaccine [RR=0.83; 95% CI (0.72, 0.95)], measles mumps rubella vaccine (MMR) [RR=0.71, 95% CI (0.61, 0.83)], or yellow fever vaccine [RR=0.70; 95% CI (0.59, 0.82)].

CONCLUSIONS

We did not find an increased risk of diagnosed type 1 diabetes and any of the study vaccines. We recommend that follow-up studies using medical record review to confirm case status should be considered to corroborate these findings.

Does medication adherence lower Medicare spending among beneficiaries with diabetes?

OBJECTIVE

To measure 3-year medication possession ratios (MPRs) for renin-angiotensin-aldosterone system (RAAS) inhibitors and statins for Medicare beneficiaries with diabetes, and to assess whether better adherence is associated with lower spending on traditional Medicare services controlling for biases common to previous adherence studies.

DATA SOURCE

Medicare Current Beneficiary Survey data from 1997 to 2005.

STUDY DESIGN

Longitudinal study of RAAS-inhibitor and statin utilization over 3 years.

DATA COLLECTION

The relationship between MPR and Medicare costs was tested in multivariate models with extensive behavioral variables to control for indication bias and healthy adherer bias.

PRINCIPAL FINDINGS

Over 3 years, median MPR values were 0.88 for RAAS-I users and 0.77 for statin users. Higher adherence was strongly associated with lower Medicare spending in the multivariate analysis. A 10 percentage point increase in statin MPR was associated with U.S.$832 lower Medicare spending (SE=219; p<.01). A 10 percentage point increase in MPR for RAAS-Is was associated with U.S.$285 lower Medicare costs (SE=114; p<.05).

CONCLUSIONS

Higher adherence with RAAS-Is and statins by Medicare beneficiaries with diabetes results in lower cumulative Medicare spending over 3 years. At the margin, Medicare savings exceed the cost of the drugs.

The preventable proportion of type 2 diabetes by ethnicity: the multiethnic cohort

PURPOSE

To estimate the population-attributable risk (PAR) associated with modifiable risk factors for diabetes among Caucasians, Native Hawaiians, and Japanese Americans in the Hawaii component of the Multiethnic Cohort.

METHODS

This analysis is based on 74,970 cohort participants ages 45-75 years who completed a questionnaire on demographics, diet, and lifestyle factors in 1993-1996. After a mean follow-up time of 12.1 (0.01-14.4) years, 8,559 diabetes cases were identified by self-report, a medication questionnaire, and through health plan linkages. Hazard ratios for diabetes and partial PARs for single and different combinations of modifiable risk factors were estimated.

RESULTS

Overweight, physical inactivity, high meat intake, no alcohol consumption, and smoking were positively associated with diabetes risk in all ethnic groups. The estimated PARs suggested that among men, 78%, and among women, 83%, of new diabetes cases could have been avoided if all individuals had been in the low risk category for all of the modifiable risk factors. The slightly lower PARs in Japanese Americans were not significantly different from those in Caucasian and Native Hawaiian subjects.

CONCLUSIONS

Although PARs varied slightly over ethnicity, our findings do not support ethnic-specific prevention strategies; interventions targeted at multiple behaviors are needed in all ethnic groups.

Diabetes prevalence by length of residence among US immigrants

Although at arrival, US immigrants have a lower prevalence of overweight compared to native born individuals, prevalence increases with increased length of residence. It is unknown whether length of residence similarly affects diabetes. Data on adults aged 18-74 years from the National Health Interview Survey were pooled from 1997 to 2005 (n = 33,499). Diabetes prevalence by length of residence was estimated by multivariable logistic regression. Diabetes prevalence was higher with increased length of residence in the US, independent of age and body mass index (<5 years residence: 3.3%; 5-<10 year, 3.4%; 10-<15 year, 4.5%; 15+ year, 5.3%; P for trend <0.001). Length of residence had the largest effect on diabetes prevalence among immigrants who arrive at 25-44 years of age (prevalence: 1.4% for <5 year vs. 11.1% for 15+ year; odds ratio = 9.7 (95% CI: 5.2-18.1)). Despite differences in the associations between diabetes prevalence and length of residence by age at immigration, diabetes prevalence at 10-≤15 and 15± years was statistically similar in each age at immigration strata. Diabetes prevalence increased with length of residence, independent of age and obesity, and was modified by age at immigration. Diabetes prevalence reaches a plateau at 10+ years of residence and diabetes prevention efforts should, therefore, start soon after migration.

Recent US Patterns and Predictors of Prevalent Diabetes among Acute Myocardial Infarction Patients

Background. Diabetes mellitus (DM) confers high vascular risk and is a growing national epidemic. We assessed clinical characteristics and prevalence of diagnosed DM among patients hospitalized with acute myocardial infarction (AMI) in the US over the last decade. Methods. Data were obtained from all states within the US that contributed to the Nationwide Inpatient Sample. All patients admitted to hospitals between 1997 and 2006 with a primary discharge diagnosis of AMI were included. Time trends in the proportion of these patients with DM diagnosis were computed. Results. The portion of patients with comorbid diabetes among AMI hospitalizations increased substantially from 18% in 1997 to 30% in 2006 (P < .0001). Absolute numbers of AMI hospitalizations in the US decreased 8% (from 729, 412 to 672, 243), while absolute numbers of AMI hospitalizations with coexisting DM rose 51% ((131, 189 to 198, 044), both (P < .0001). Women with AMI were significantly more likely to have DM than similarly aged men, but these differences diminished with increasing age. Conclusion. Although overall hospitalizations for AMI in the US diminished over the last decade, prevalence of diabetes rose substantially. This may have important consequences for the future societal vascular disease burden.

Validation of a case definition for osteoporosis disease surveillance

A simple case definition for osteoporosis case diagnosis is feasible based upon administrative health data. This may facilitate implementation of a population-based osteoporosis surveillance program, providing information that could help to inform and guide screening, prevention, and treatment resources.

INTRODUCTION

Our aim was to construct and validate a simplified algorithm for osteoporosis case ascertainment from administrative databases that would be suitable for disease surveillance.

METHODS

Multiple classification rules were applied to different sets of hospital diagnosis, physician claims diagnosis, and prescription drug variables from Manitoba, Canada. Algorithms were validated against results from a regional bone mineral density testing program that identified bone mineral density (BMD) measurements in 4,015 women age 50 years and older with at least one BMD test between April 1, 2000 and March 31, 2001.

RESULTS

Sensitivity as high as 93.3% was achieved with 3 years of data. Specificity ranged from 50.8% to 91.4% overall, and from 81.2% to 99.1% for discriminating osteoporotic from normal BMD. Sensitivity and overall accuracy were generally lower for algorithms based on diagnosis codes alone than for algorithms that included osteoporosis prescriptions. In the subgroup without prior osteoporotic fractures or chronic corticosteroid use, one simple algorithm (one hospital diagnosis, physician claims diagnosis, or osteoporosis prescription within 1 year) gave accuracy measures exceeding 90% for discriminating osteoporosis from normal BMD across a wide range of disease prevalence.

CONCLUSIONS

A relatively simple case definition for osteoporosis surveillance based upon administrative health data can achieve an acceptable level of sensitivity, specificity, and accuracy. Performance is enhanced when the case definition includes osteoporosis medication use in the formulation.

Investigating concordance in diabetes diagnosis between primary care charts (electronic medical records) and health administrative data: a retrospective cohort study

BACKGROUND

Electronic medical records contain valuable clinical information not readily available elsewhere. Accordingly, they hold important potential for contributing to and enhancing chronic disease registries with the goal of improving chronic disease management; however a standard for diagnoses of conditions such as diabetes remains to be developed. The purpose of this study was to establish a validated electronic medical record definition for diabetes.

METHODS

We constructed a retrospective cohort using health administrative data from the Institute for Clinical Evaluative Sciences Ontario Diabetes Database linked with electronic medical records from the Deliver Primary Healthcare Information Project using data from 1 April 2006-31 March 2008 (N = 19,443). We systematically examined eight definitions for diabetes diagnosis, both established and proposed.

RESULTS

The definition that identified the highest number of patients with diabetes (N = 2,180) while limiting to those with the highest probability of having diabetes was: individuals with ≥2 abnormal plasma glucose tests, or diabetes on the problem list, or insulin prescription, or ≥2 oral anti-diabetic agents, or HbA1c ≥6.5%. Compared to the Ontario Diabetes Database, this definition identified 13% more patients while maintaining good sensitivity (75%) and specificity (98%).

CONCLUSIONS

This study establishes the feasibility of developing an electronic medical record standard definition of diabetes and validates an algorithm for use in this context. While the algorithm may need to be tailored to fit available data in different electronic medical records, it contributes to the establishment of validated disease registries with the goal of enhancing research, and enabling quality improvement in clinical care and patient self-management.

Risk of diabetes in U.S. military service members in relation to combat deployment and mental health

OBJECTIVE

Few prospective data exist on the risk of diabetes in individuals serving in the U.S. military. The objectives of this study were to determine whether military deployment, combat exposures, and mental health conditions were related to the risk of newly reported diabetes over 3 years.

RESEARCH DESIGN AND METHODS

Data were from Millennium Cohort Study participants who completed baseline (July 2001-June 2003) and follow-up (June 2004-February 2006) questionnaires (follow-up response rate = 71.4%). After exclusion criteria were applied, adjusted analyses included 44,754 participants (median age 36 years, range 18-68 years). Survey instruments collected demographics, height, weight, lifestyle, military service, clinician-diagnosed diabetes, and other physical and mental health conditions. Deployment was defined by U.S. Department of Defense databases, and combat exposure was assessed by self-report at follow-up. Odds of newly reported diabetes were estimated using logistic regression analysis.

RESULTS

Occurrence of diabetes during follow-up was 3 per 1,000 person-years. Individuals reporting diabetes at follow-up were significantly older, had greater baseline BMI, and were less likely to be Caucasian. After adjustment for age, sex, BMI, education, race/ethnicity, military service characteristics, and mental health conditions, only baseline posttraumatic stress disorder (PTSD) was significantly associated with risk of diabetes (odds ratio 2.07 [95% CI 1.31-3.29]). Deployments since September 2001 were not significantly related to higher diabetes risk, with or without combat exposure.

CONCLUSIONS

In this military cohort, PTSD symptoms at baseline but not other mental health symptoms or military deployment experience were significantly associated with future risk of self-reported diabetes.

Validating ICD coding algorithms for diabetes mellitus from administrative data

AIM

To assess validity of diabetes International Classification of Disease (ICD) 9 and 10 coding algorithms from administrative data using physicians' charts as the 'gold standard' across time periods and geographic regions.

METHODS

From 48 urban and 16 rural general practitioners' clinics in Alberta and British Columbia, Canada, we randomly selected 50patient charts/clinic for those who visited the clinic in either 2001 or 2004. Reviewed chart data were linked with inpatient discharge abstract and physician claims administrative data. We identified patients with diabetes in the administrative databases using ICD-9 code 250.xx and ICD-10 codes E10.x-E14.x.

RESULTS

The prevalence of diabetes was 8.1% among clinic charts. The coding algorithm of "2 physician claims within 2 years or 1 hospitalization with the relevant diabetes ICD codes" had higher validity than other 7 algorithms assessed (sensitivity 92.3%, specificity 96.9%, positive predictive value 77.2%, and negative predictive value 99.3%). After adjustment for age, sex, and comorbid conditions, sensitivity and positive predictive values were not significantly different between time periods and regions.

CONCLUSION

Diabetes could be accurately identified in administrative data using the following case definition "2 physician claims within 2 years or 1 hospital discharge abstract record with diagnosis codes 250.xx or E10.x-E14.x".

Socioeconomic status and risk of diabetes-related mortality in the U.S

OBJECTIVE

We examined disparities in diabetes-related mortality for socioeconomic status (SES) groups in nationally representative U.S. samples.

METHODS

We analyzed National Health Interview Survey respondents linked to their death records and included those eligible for mortality follow-up who were aged 25 years and older at the time of interview and not missing information on covariates (n=527,426). We measured SES by education and family income. There were 5,613 diabetes-related deaths.

RESULTS

Having less than a high school education was associated with a twofold higher mortality from diabetes, after controlling for age, gender, race/ethnicity, marital status, and body mass index, compared with adults with a college degree or higher education level (relative hazard [RH] = 2.05, 95% confidence interval [CI] 1.78, 2.35). Having a family income below poverty level was associated with a twofold higher mortality after adjustments compared with adults with the highest family incomes (RH=2.41, 95% CI 2.05, 2.84). Approximately one-quarter of the excess risk among those in the lowest SES categories was explained by adjusting for potential confounders.

CONCLUSION

Findings from this nationally representative cohort demonstrate a socioeconomic gradient in diabetes-related mortality, with both education and income being important determinants of the risk of death.

Trends in frequency of reporting improper diabetes-related cause-of-death statements on death certificates, 1985-2005: An algorithm to identify incorrect causal sequences

This study aimed to examine the changes in frequency of reporting improper diabetes-related cause-of-death statements on death certificates based on Multiple-Cause Mortality Files of the United States from 1985 to 2005. An algorithm was developed to identify the causes of death with incorrect causal sequences by using decision tables developed by the National Center for Health Statistics. In 1985, 2 or more diagnoses per line were reported on 35% of death certificates with mention of diabetes in Part I of the death certificate. This percentage decreased to 19% in 2005. In contrast, the prevalence of reporting incorrect causal sequences on death certificates on which diabetes was reported in Part I increased from 22% in 1985 to 35% in 2005. The authors suggest that the most plausible explanation of increasing reporting of incorrect causal sequences was the drastic increase of reporting multiple conditions (especially cardiovascular diseases and cancers) among deaths with mention of diabetes, which made the determination of underlying cause of death much more difficult.

Trends in the prevalence and comorbidities of diabetes mellitus in nursing home residents in the United States: 1995-2004

OBJECTIVES

To estimate trends in the prevalence and comorbidities of diabetes mellitus (DM) in U.S. nursing homes from 1995 to 2004.

DESIGN

SAS callable SUDAAN was used to adjust for the complex sample design and assess changes in prevalence of DM and comorbidities during the study period in the National Nursing Home Surveys. Trends were assessed using weighted least squares linear regression. Multiple logistic regressions were used to calculate predictive margins.

SETTING

A continuing series of two-stage, cross-sectional probability national sampling surveys.

PARTICIPANTS

Residents aged 55 and older: 1995 (n=7,722), 1997 (n=7,717), 1999 (n=7,809), and 2004 (n=12,786).

MEASUREMENTS

DM and its comorbidities identified using a standard set of diagnosis codes.

RESULTS

The estimated crude prevalence of DM increased from 16.9% in 1995 to 26.4% in 2004 in male nursing home residents and from 16.1% to 22.2% in female residents (all P<.05). Male and female residents aged 85 and older and those with high functional impairment showed a significant increasing trend in DM (all P<.05). In people with DM, multivariate-adjusted prevalence of cardiovascular disease increased from 59.6% to 75.4% for men and from 68.1% to 78.7% for women (all P<.05). Prevalence of most other comorbidities did not increase significantly.

CONCLUSION

The burden of DM in residents of U.S. nursing homes has increased since 1995. This could be due to increasing DM prevalence in the general population or to changes in the population that nursing homes serve. Nursing home care practices may need to change to meet residents' changing needs.

Multistate study of the epidemiology of clubfoot

BACKGROUND

Although clubfoot is a common birth defect, with a prevalence of approximately 1 per 1000 livebirths, the etiology of clubfoot remains largely unknown. Studies of the prevalence and risk factors for clubfoot in the United States have previously been limited to specific states. The purpose of this study was to pool data from several birth defects surveillance programs to better estimate the prevalence of clubfoot and investigate its risk factors.

METHODS

The 10 population-based birth defects surveillance programs that participated in this study ascertained 6139 cases of clubfoot from 2001 through 2005. A random sample of 10 controls per case, matched on year and state of birth, was selected from birth certificates. Data on infant and maternal risk factors were collected from birth certificates. Prevalence was calculated by pooling the state-specific data. Conditional logistic regression was used to investigate the association between risk factors and clubfoot.

RESULTS

The overall prevalence of clubfoot was 1.29 per 1000 livebirths; 1.38 among non-Hispanic whites, 1.30 among Hispanics, and 1.14 among non-Hispanic blacks or African Americans. Maternal age, parity, education, and marital status were significantly associated with clubfoot. Maternal smoking and diabetes also showed significant associations. Several of these observed associations were consistent between surveillance programs.

CONCLUSIONS

We estimated the prevalence of clubfoot using data from several birth defects programs, representing one-quarter of all births in the United States. Our findings underline the importance of birth defects surveillance programs and their utility in monitoring population-based prevalence and investigating risk factors.

Comparative device assessments: Humalog KwikPen compared with vial and syringe and FlexPen

PURPOSE

The purpose of this study was to compare pen device-naïve patients' preferences for Humalog KwikPen (insulin lispro injection) (Eli Lilly and Company, Indianapolis, IN) to use of a vial and syringe and FlexPen(R) (insulin aspart injection) (Novo Nordisk A/S, Bagsvaerd, Denmark).

METHODS

This open-label, randomized, crossover 1-day study tested the hypotheses that KwikPen was preferred to vial and syringe, and if this was found to be a significant preference, that KwikPen was preferred to FlexPen. Accuracy of doses prepared, ease of use via insulin device assessment battery, and preference via insulin device preference battery were administered following each pen evaluation, and a final preference question administered following the evaluation of both pens. Clinical measures were not included as subjects injected into an appliance to simulate the injection experience. Primary outcome variables were evaluated by Question 13 of the insulin device preference battery and the final preference question.

RESULTS

Among 232 enrolled patients randomized to 1 of 4 sequences (n = 58), Humalog KwikPen was significantly preferred over vial and syringe and over FlexPen. After patients were asked to assess Humalog KwikPen or FlexPen versus V&S by choosing "strongly agreed" or "agreed" to the following attributes: easy to use, easy to hold in their hands when injecting, and easy to press the injection button, the results exhibited significant differences in patient responses. Humalog KwikPen was significantly more accurate and was preferred to vial and syringe in appearance, quality, discretion, convenience, public use, easy to learn, easy to use, reliability, dose confidence, following insulin regimen, overall satisfaction, and recommendation to others.

CONCLUSIONS

Humalog KwikPen was significantly preferred over vial and syringe and FlexPen. When compared with vial and syringe, Humalog KwikPen and FlexPen were easier to use and operate, demonstrated superior accuracy of doses prepared, and preferred by pen-naïve users.

Do we really know the cause of death of the very old? Comparison between official mortality statistics and cohort study classification

Causes of death of 625 subjects who died during the 4-year follow-up of a large population-based elderly cohort (Three-City study) were independently classified by the study adjudication committee and the national mortality register. The former used all available data about the cause of death (hospital records, medical data obtained from family physicians or specialists, and proxy interviews) and the latter used internationally standardized recommendations for processing death certificate data. Comparison showed a moderate overall agreement for underlying cause of death between the study adjudication committee and the national register (kappa = 0.51). Differences were found especially for cardiovascular diseases (20.6% of deaths from the study committee vs. 32.5% from the national register) and ill-defined causes of death (22.7 vs. 4%). The proportion of disagreement increased in participants dying at age >85 compared to those dying at age < or =70 (adjusted odds ratio = 2.46, 95% confidence interval = 1.10-5.49). It was also higher when the study committee used hospital record data for defining cause of death, compared to adjudication based on data obtained from proxy (adjusted odds ratio = 1.85, 95% CI = 1.09-3.14). These findings raise questions about the validity of national mortality registers in very old persons. Disease-specific causes of death, especially vascular diseases, could be overestimated in this age group.

Joint modeling of longitudinal changes in depressive symptoms and mortality in a sample of community-dwelling elderly people

OBJECTIVE

To use a joint modeling approach to examine the association between longitudinal changes in depressive symptoms and mortality. Research on the relationship of depression to mortality has yielded mixed results. Limitations of previous studies include mostly one-time assessment of depression, short follow-ups, and failure to model appropriately changes in depression.

METHODS

Data were obtained from the Florida Retirement Study, a prospective cohort study of community-dwelling oldest old individuals. At baseline, 879 people (mean age = 80.6 years, 65.8% women) had a comprehensive psychosocial assessment, including the Center of Epidemiological Studies-Depression Scale (CES-D). They were then assessed annually up to 11 years. Longitudinal changes of CES-D, modeled by a joint modeling approach of repeated measures and survival data, were used to predict mortality at follow-up (15 years after baseline), at the same time adjusting for five classes of covariates.

RESULTS

The total mortality rate was 69.9%. CES-D at baseline was not predictive of mortality at 15-year follow-up after adjusting for baseline covariates. The joint modeling revealed that an annual increase of 1 point in CES-D scores over the years was associated with a 57% higher risk of mortality (HR = 1.57, p < .001) at follow-up. Compared with those whose CES-D scores were stable over time, subjects with increasing CED-D scores over time had a 70% increase in mortality risk, p < .001, and their median survival time was 4 years shorter.

CONCLUSION

Although baseline CES-D was not predictive of mortality, the increase in depressive symptoms over time was associated with higher mortality. It is important to assess longitudinal changes in depression.

Diabetes incidence based on linkages with health plans: the multiethnic cohort

OBJECTIVE

Using the Hawaii component of the Multiethnic Cohort (MEC), we estimated diabetes incidence among Caucasians, Japanese Americans, and Native Hawaiians.

RESEARCH DESIGN AND METHODS

After excluding subjects who reported diabetes at baseline or had missing values, 93,860 cohort members were part of this analysis. New case subjects were identified through a follow-up questionnaire (1999-2000), a medication questionnaire (2003-2006), and linkage with two major health plans (2007). We computed age-standardized incidence rates and estimated hazard ratios (HRs) for ethnicity, BMI, education, and combined effects of these variables using Cox regression analysis.

RESULTS

After a total follow-up time of 1,119,224 person-years, 11,838 incident diabetic case subjects were identified with an annual incidence rate of 10.4 per 1,000 person-years. Native Hawaiians had the highest rate with 15.5, followed by Japanese Americans with 12.5, and Caucasians with 5.8 per 1,000 person-years; the adjusted HRs were 2.65 for Japanese Americans and 1.93 for Native Hawaiians. BMI was positively related to incidence in all ethnic groups. Compared with the lowest category, the respective HRs for BMIs of 22.0-24.9, 25.0-29.9, and > or =30.0 kg/m(2) were 2.10, 4.12, and 9.48. However, the risk was highest for Japanese Americans and intermediate for Native Hawaiians in each BMI category. Educational achievement showed an inverse association with diabetes risk, but the protective effect was limited to Caucasians.

CONCLUSIONS

Within this multiethnic population, diabetes incidence was twofold higher in Japanese Americans and Native Hawaiians than in Caucasians. The significant interaction of ethnicity with BMI and education suggests ethnic differences in diabetes etiology.

Overweight and diabetes prevalence among US immigrants

OBJECTIVES

We estimated the prevalence of overweight and diabetes among US immigrants by region of birth.

METHODS

We analyzed data on 34 456 US immigrant adults from the National Health Interview Survey, pooling years 1997 to 2005. We estimated age- and gender-adjusted and multivariable-adjusted overweight and diabetes prevalence by region of birth using logistic regression.

RESULTS

Both men (odds ratio [OR] = 3.3; 95% confidence interval [CI] = 1.9, 5.8) and women (OR = 4.2; 95% CI = 2.3, 7.7) from the Indian subcontinent were more likely than were European migrants to have diabetes without corresponding increased risk of being overweight. Men and women from Mexico, Central America, or the Caribbean were more likely to be overweight (men: OR = 1.5; 95% CI = 1.3, 1.7; women: OR = 2.0; 95% CI = 1.7, 2.2) and to have diabetes (men: OR = 2.0; 95% CI = 1.4, 2.9; women: OR = 2.0; 95% CI = 1.4, 2.8) than were European migrants.

CONCLUSIONS

Considerable heterogeneity in both prevalence of overweight and diabetes by region of birth highlights the importance of making this distinction among US immigrants to better identify subgroups with higher risks of these conditions.

Trends in nutrient intake among adults with diabetes in the United States: 1988-2004

BACKGROUND

Weight loss through dietary modification is key to type 2 diabetes self-management, yet few nationally representative data exist on dietary trends among people with diabetes.

OBJECTIVE

To examine dietary changes, via nutrient intakes, among US adults with diabetes between 1988 and 2004.

DESIGN

Nutrition data from the cross-sectional National Health and Nutrition Examination Surveys (Phase I: 1988-1990 and Phase II: 1991-1994) and 1999-2004 of adults with self-reported diabetes were examined. Twenty-four-hour dietary recall data were used to assess changes in energy; carbohydrate; protein; total, saturated, polyunsaturated, and monounsaturated fat; cholesterol; fiber; sodium; and alcohol intake.

STATISTICAL ANALYSES

Consumption of total energy and specific nutrients per day were estimated by survey, controlled for age and sex, using multiple linear regression and adjusted means (with standard errors).

RESULTS

Between 1988 and 2004 there was no significant change in self-reported total energy consumption among adults with self-reported diabetes (1,941 kcal/day in 1988-1990 to 2,109 kcal/day in 2003-2004, P for trend=0.22). However, there was a significant increase in the consumption of carbohydrate (209 g/day in 1988-1990 to 241 g/day in 2003-2004; P for trend=0.02). In analyses stratified by age group, changes in dietary consumption were noted among persons aged 45 to 64 years; specifically, increases in total energy (1,770 to 2,100 kcal/day, P for trend =0.01) and carbohydrate consumption (195 to 234 g/day, P for trend=0.02).

CONCLUSIONS

Despite recommendations to lose weight, daily energy consumption by individuals with diabetes showed no significant change, except in individuals aged 45 to 64 years, where an increase was observed. Overall, there was an increase in carbohydrate consumption. Emphasizing the equal importance of energy reduction and changes in dietary composition for people with diabetes is important for optimal self-management.

Increased persistency in medication use by U.S. Medicare beneficiaries with diabetes is associated with lower hospitalization rates and cost savings

OBJECTIVE

To assess the relationship between annual fills for antidiabetes medications, ACE inhibitors, angiotensin II receptor blockers (ARBs), and lipid-lowering agents on hospitalization and Medicare spending for beneficiaries with diabetes.

RESEARCH DESIGN AND METHODS

Using Medicare Current Beneficiary Survey data from 1997 to 2004, we identified 7,441 community-dwelling beneficiaries with diabetes, who contributed 14,317 person-years of data for the analysis. We used multivariate regression analysis to estimate the effect of persistency in medication fills on hospitalization risk, hospital days, and Medicare spending.

RESULTS

For users of older oral antidiabetes agents, ACE inhibitors, ARBs, and statins, each additional prescription fill was associated with significantly lower risk of hospitalization, fewer hospital days, and lower Medicare spending.

CONCLUSIONS

These results suggest an economic case for promoting greater persistency in use of drugs with approved indications by Medicare beneficiaries with diabetes; however, additional research is needed to corroborate the study's cross-sectional findings.