Patient-level estimates of the cost of complications in diabetes in a managed-care population

GelMA/PEGDA microneedles patch loaded with HUVECs-derived exosomes and Tazarotene promote diabetic wound healing

Clinical work and research on diabetic wound repair remain challenging globally. Although various conventional wound dressings have been continuously developed, the efficacy is unsatisfactory. The effect of drug delivery is limited by the depth of penetration. The sustained release of biomolecules from biological wound dressings is a promising treatment approach to wound healing. An assortment of cell-derived exosomes (exos) have been proved to be instrumental in tissue regeneration, and researchers are dedicated to developing biomolecules carriers with unique properties. Herein, we reported a methacrylate gelatin (GelMA) microneedles (MNs) patch to achieve transdermal and controlled release of exos and tazarotene. Our MNs patch comprising GelMA/PEGDA hydrogel has distinctive biological features that maintain the biological activity of exos and drugs in vitro. Additionally, its unique physical structure prevents it from being tightly attached to the skin of the wound, it promotes cell migration, angiogenesis by slowly releasing exos and tazarotene in the deep layer of the skin. The full-thickness cutaneous wound on a diabetic mouse model was carried out to demonstrate the therapeutic effects of GelMA/PEGDA@T + exos MNs patch. As a result, our GelMA/PEGDA@T + exos MNs patch presents a potentially valuable method for repairing diabetic wound in clinical applications.

Efficacy and safety of intramuscular administration of allogeneic adipose tissue derived and expanded mesenchymal stromal cells in diabetic patients with critical limb ischemia with no possibility of revascularization: study protocol for a randomized controlled double-blind phase II clinical trial (The NOMA Trial)

Background

Chronic lower limb ischemia develops earlier and more frequently in patients with type 2 diabetes mellitus. Diabetes remains the main cause of lower-extremity non-traumatic amputations. Current medical treatment, based on antiplatelet therapy and statins, has demonstrated deficient improvement of the disease. In recent years, research has shown that it is possible to improve tissue perfusion through therapeutic angiogenesis. Both in animal models and humans, it has been shown that cell therapy can induce therapeutic angiogenesis, making mesenchymal stromal cell-based therapy one of the most promising therapeutic alternatives. The aim of this study is to evaluate the feasibility, safety, and efficacy of cell therapy based on mesenchymal stromal cells derived from adipose tissue intramuscular administration to patients with type 2 diabetes mellitus with critical limb ischemia and without possibility of revascularization.

Methods

A multicenter, randomized double-blind, placebo-controlled trial has been designed. Ninety eligible patients will be randomly assigned at a ratio 1:1:1 to one of the following: control group (n = 30), low-cell dose treatment group (n = 30), and high-cell dose treatment group (n = 30). Treatment will be administered in a single-dose way and patients will be followed for 12 months. Primary outcome (safety) will be evaluated by measuring the rate of adverse events within the study period. Secondary outcomes (efficacy) will be measured by assessing clinical, analytical, and imaging-test parameters. Tertiary outcome (quality of life) will be evaluated with SF-12 and VascuQol-6 scales.

Discussion

Chronic lower limb ischemia has limited therapeutic options and constitutes a public health problem in both developed and underdeveloped countries. Given that the current treatment is not established in daily clinical practice, it is essential to provide evidence-based data that allow taking a step forward in its clinical development. Also, the multidisciplinary coordination exercise needed to develop this clinical trial protocol will undoubtfully be useful to conduct academic clinical trials in the field of cell therapy in the near future.

Trial registration

ClinicalTrials.govNCT04466007. Registered on January 07, 2020. All items from the World Health Organization Trial Registration Data Set are included within the body of the protocol.

Type 2 Diabetes Mellitus (T2DM) "Remission" in Non-bariatric Patients 65 Years and Older

Objective: To analyze the factors associated with type 2 diabetes mellitus (T2DM) “remission” in non-bariatric Medicare patients 65 years and older.

Research Design and Methods: A retrospective cohort analysis of a Medicare Advantage health plan was conducted using administrative data. An individual was identified as T2DM if the individual had: ≥ 2 medical claims for T2DM coded 250.xx excluding type 1 diabetes; or ≥ 2 pharmacy claims related to T2DM; or ≥ 2 combined medical claims, pharmacy claims for T2DM in 12 months. A T2DM individual was in “remission” if they had no T2DM related claims for more than 12 months continuously. This is different from the standard American Diabetes Association (ADA) definition of remission which includes HbA1c values and hence is represented in quotation (as “remission”). 10,059 T2DM individuals were evaluated over a period of 8 years from 2008 to 2015. Cox proportional hazards was used to identify significant variables associated with T2DM “remission.”

Results: 4.97% of patients studied met the definition of T2DM “remission” in the study cohort. After adjusting for covariates this study found a number of variables associated with T2DM “remission” that were not previously reported: no statin use; low diabetes complications severity index score; no hypertension; no neuropathy; no retinopathy; race (non-white and non-African American); presence of other chronic ischemic heart disease (IHD) and females (p < 0.05).

Conclusion: T2DM “remission” in Medicare patients 65 years and older is observed in a community setting in a small proportion of non-bariatric patients.

Controlled-release neurotensin-loaded silk fibroin dressings improve wound healing in diabetic rat model

Diabetic foot ulcers (DFU), which may lead to lower extremity amputation, is one of the severe and chronic complications of diabetic mellitus. This study aims to develop, and use dressings based on Silk fibroin (SF) as the scaffold material, gelatin microspheres (GMs) as the carrier for the neurotensin (NT), a neuropeptide that acts as an inflammatory modulator in wound healing and NT as accelerate wound healing drug to treat DFU. We evaluated the wound healing processes and neo-tissue formation in rat diabetic model by macroscopic observation, histological observation (H&E staining and Masson's trichrome staining) and immunofluorescence analysis at 3, 7, 14, 21 and 28 post-operation days. Our results show that the NT/GMs/SF group performance the best not only in macroscopic healing and less scars in 28 post-operation days, but also in fibroblast accumulation in tissue granulation, collagen expression and deposition at the wound site. From release profiles, we can know the GMs are a good carrier for control release drugs. The SEM results shows that the NT/GMs/SF dressings have an average pore size are 40–80 μm and a porosity of ∼85%, this pore size is suit for wound healing regeneration. These results suggest that the NT/GMs/SF dressings may work as an effective support for control release NT to promote DFU wound healing.

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This study aims to develop, and use dressings based on Silk fibroin (SF) as the scaffold material, gelatin microspheres (GMs) as the carrier for the Neurotensin (NT), a neuropeptide that acts as an inflammatory modulator in wound healing and NT as accelerate wound healing drug to treat DFU.

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The NT/GMs/SF dressings stimulated fibroblast accumulation in tissue granulation, collagen expression and deposition at the wound site, which lead to the production of a more organized collagen matrix.

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This treatment effectively accelerating wound regeneration and re-epithelialization.

Complication Rates and Downstream Medical Costs Associated With Invasive Diagnostic Procedures for Lung Abnormalities in the Community Setting

IMPORTANCE

The Centers for Medicare & Medicaid Services added lung cancer screening with low-dose computed tomography (LDCT) as a Medicare preventive service benefit in 2015 following findings from the National Lung Screening Trial (NLST) that showed a 16% reduction in lung cancer mortality associated with LDCT. A challenge in developing and promoting a national lung cancer screening program is the high false-positive rate of LDCT because abnormal findings from thoracic imaging often trigger subsequent invasive diagnostic procedures and could lead to postprocedural complications.

OBJECTIVE

To determine the complication rates and downstream medical costs associated with invasive diagnostic procedures performed for identification of lung abnormalities in the community setting.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort study of non-protocol-driven community practices captured in MarketScan Commercial Claims & Encounters and Medicare supplemental databases was conducted. A nationally representative sample of 344 510 patients aged 55 to 77 years who underwent invasive diagnostic procedures between 2008 and 2013 was included.

MAIN OUTCOMES AND MEASURES

One-year complication rates were calculated for 4 groups of invasive diagnostic procedures. The complication rates and costs were further stratified by age group.

RESULTS

Of the 344 510 individuals aged 55 to 77 years included in the study, 174 702 comprised the study group (109 363 [62.6%] women) and 169 808 served as the control group (106 007 [62.4%] women). The estimated complication rate was 22.2% (95% CI, 21.7%-22.7%) for individuals in the young age group and 23.8% (95% CI, 23.0%-24.6%) for those in the Medicare group; the rates were approximately twice as high as those reported in the NLST (9.8% and 8.5%, respectively). The mean incremental complication costs were $6320 (95% CI, $5863-$6777) for minor complications to $56 845 (95% CI, $47 953-$65 737) for major complications.

CONCLUSIONS AND RELEVANCE

The rates of complications after invasive diagnostic procedures were higher than the rates reported in clinical trials. Physicians and patients should be aware of the potential risks of subsequent adverse events and their high downstream costs in the shared decision-making process.

Healthcare Cost Development in a Type 2 Diabetes Patient Population on Glucose-Lowering Drug Treatment: A Nationwide Observational Study 2006-2014

OBJECTIVE

The objective of this study was to describe healthcare resource use and cost development in Sweden during 2006-2014 in a type 2 diabetes (T2D) population receiving glucose-lowering drugs (GLDs).

METHODS

In- and outpatient healthcare resource use and costs were extracted from mandatory national registries: the Cause of Death Register; the National Patient Register; and the Prescribed Drug Register. Primary care data were estimated based on an observational study including patients from 84 primary care centers in Sweden. Numbers of any cause inpatient, outpatient, and primary care contacts were extracted and direct healthcare costs were estimated.

RESULTS

During 2006-2014, the number of inpatient and primary care contacts increased by approximately 70% (from 45,559 to 78,245 and from 4.9 to 8.8 million, respectively) and outpatient care contacts almost doubled (from 105,653 to 209,417). Mean annual per patient costs increased by 13%, reaching €4594. Total healthcare costs increased from €835 million to €1.684 billion. Inpatient care costs constituted 47% of total costs in 2014 (€783 million), primary care accounted for 24% (€405 million), outpatient care 18% (€303 million), non-GLD medications 6% (€109 million), and GLDs 5% (€84 million). Cardiovascular diseases (CVDs) were the most costly disease group in inpatient care (26%), whereas managing unspecified factors influencing health and T2D-associated diseases were the most costly in outpatient care (16 and 11%, respectively).

CONCLUSIONS

The healthcare costs of the GLD-treated T2D population doubled during 2006-2014, mostly driven by the increasing size of this population, of which inpatient care accounted for 47%. GLDs constituted the smallest share of costs. CVD was the most resource-requiring disease group.

Differences in All-Cause Health Care Utilization and Costs in a Type 2 Diabetes Mellitus Population with and Without a History of Cardiovascular Disease

BACKGROUND

Multiple studies have reported that type 2 diabetes mellitus (T2DM) is a major risk factor for cardiovascular diseases (CVD), and presence of T2DM and CVD increases risk of death. There is growing interest in examining the effects of antidiabetic treatments on the reduction of cardiovascular events in T2DM adults with a history of CVD and thus at higher risk of cardiovascular events.

OBJECTIVE

To estimate the incremental all-cause health care utilization and costs among adults with T2DM and a history of CVD compared with adults without a history of CVD, using a national linked electronic medical records (EMR) and claims database.

METHODS

Adults aged ≥ 18 years with evidence of at least 1 T2DM-related diagnosis code or antidiabetic medication (date of earliest occurrence was defined as the index date) in calendar year 2012 were identified. The population was divided into 2 cohorts (with and without a history of CVD) and followed until the end of their enrollment coverage, death, or 12 months, whichever came first. Multivariable generalized linear models were used to assess differences in health care utilization and per patient per month (PPPM) total costs (plan- and patient-paid amount for health care services) between the 2 groups during the post-index year, while adjusting for an a priori list of demographic and clinical characteristics.

RESULTS

A total of 138,018 adults with T2DM was identified, of which 16,547 (12%) had a history of CVD. The unadjusted resource utilization (outpatient: 27.5 vs. 17.8; emergency room [ER]: 0.8 vs. 0.4; inpatient: 0.4 vs. 0.2 days; and total unique drug prescriptions: 10.1 vs. 8.3) and PPPM total health care costs ($2,655.1 vs. $1,435.0) were significantly higher in T2DM adults with a history of CVD versus T2DM adults without a history of CVD. The adjusted models revealed that T2DM adults with a history of CVD had a 31% higher number of ER visits (rate ratio [RR] = 1.31, 95% CI = 1.25-1.37); 27% more inpatient visits (RR = 1.27, 95% CI = 1.21-1.34); 15% longer mean inpatient length of stay (RR = 1.15, 95% CI = 1.06-1.25); and 11% more outpatient visits (RR = 1.11, 95% CI = 1.09-1.13) compared with T2DM adults without a history of CVD. Furthermore, the difference in total PPPM health care cost was found to be 16% ($200) higher in adults with a history of CVD (RR = 1.16, 95% CI = 1.13-1.19). PPPM costs associated with outpatient and ER visits were approximately 21% and 19% higher among adults with a history of CVD, respectively (P < 0.0001), while costs for inpatient visits were similar between the 2 groups. In addition, a subgroup analysis revealed that adjusted differences in PPPM total cost was larger in the younger age group (56% higher cost in those aged < 45 years) and diminished in the older age group (only 2% higher in those aged ≥ 65 years).

CONCLUSIONS

Study findings showed that resource utilization and costs remains significantly higher in T2DM patients with a history of CVD compared with patients without a history of CVD even after controlling for significant patient comorbid and demographic characteristics. Also, younger age groups had higher differences in outcomes compared with older age groups. This study underscores the importance of cost-effective interventions that may reduce economic burden in this T2DM population with a history of CVD.

DISCLOSURES

This study was funded by Boehringer Ingelheim. At the time of this study, Mehta and Mountford were employed by IQVIA, which received funding from Boehringer Ingelheim to conduct this study. Mountford is employed by Allergan, which has no connection with this study. Ghosh, Sander, and Kuti are employed by Boehringer Ingelheim. Study concept and design were contributed by Mountford, Mehta, and Ghosh, along with Sander and Kuti. Mountford and Mehta collected the data, and data interpretation was performed by all the authors. The manuscript was written by Sander and Kuti, along with the other authors, and revised by Mehta and Gosh, along with the other authors.

Direct medical costs of diabetes mellitus in the year of mortality and year preceding the year of mortality

AIM

To report the health resource use and estimate the direct medical costs among patients with diabetes mellitus (DM) in the year of mortality and the year preceding the year of mortality.

MATERIALS AND METHODS

We analysed data from a population-based, retrospective cohort study including all adults with a DM diagnosis in Hong Kong between 2009 and 2013, and who died between January 1, 2010 and December 31, 2013. The annual direct medical costs in the year of mortality and the year preceding the year of mortality were determined by summing the costs of health services utilized within the respective year. The costs were analysed by gender, the presence of comorbidities, diabetic complications and primary cause of death.

RESULTS

A total of 10 649 patients met the eligibility criteria for analysis. On average, the direct medical costs in the year of death were 1.947 times higher than those in the year before death. Men and women with DM incurred similar costs in the year preceding the year of mortality and in the mortality year. Patients with any diabetic complications incurred greater costs in the year of mortality and the year before mortality than those without.

CONCLUSIONS

This analysis provides new evidence on incorporating additional direct medical costs in the mortality year, and refining the structure of total cost estimates for use in costing and cost-effectiveness analyses of interventions for DM.

Annual direct medical costs associated with diabetes-related complications in the event year and in subsequent years in Hong Kong

AIM

To develop models to estimate the direct medical costs associated with diabetes-related complications in the event year and in subsequent years.

METHODS

The public direct medical costs associated with 13 diabetes-related complications were estimated among a cohort of 128 353 people with diabetes over 5 years. Private direct medical costs were estimated from a cross-sectional survey among 1825 people with diabetes. We used panel data regression with fixed effects to investigate the impact of each complication on direct medical costs in the event year and subsequent years, adjusting for age and co-existing complications.

RESULTS

The expected annual public direct medical cost for the baseline case was US$1,521 (95% CI 1,518 to 1,525) or a 65-year-old person with diabetes without complications. A new lower limb ulcer was associated with the biggest increase, with a multiplier of 9.38 (95% CI 8.49 to 10.37). New end-stage renal disease and stroke increased the annual medical cost by 5.23 (95% CI 4.70 to 5.82) and 5.94 (95% CI 5.79 to 6.10) times, respectively. History of acute myocardial infarction, congestive heart failure, stroke, end-stage renal disease and lower limb ulcer increased the cost by 2-3 times. The expected annual private direct medical cost of the baseline case was US$187 (95% CI 135 to 258) for a 65-year-old man without complications. Heart disease, stroke, sight-threatening diabetic retinopathy and end-stage renal disease increased the private medical costs by 1.5 to 2.5 times.

CONCLUSIONS

Wide variations in direct medical cost in event year and subsequent years across different major complications were observed. Input of these data would be essential for economic evaluations of diabetes management programmes.

Public health facility resource availability and provider adherence to first antenatal guidelines in a low resource setting in Accra, Ghana

Background

Lack of resources has been identified as a reason for non-adherence to clinical guidelines. Our aim was to describe public health facility resource availability in relation to provider adherence to first antenatal visit guidelines.

Methods

A cross-sectional analysis of the baseline data of a prospective cohort study on adherence to first antenatal care visit guidelines was carried out in 11 facilities in the Greater Accra Region of Ghana. Provider adherence was studied in relation to health facility resource availability such as antenatal workload for clinical staffs, routine antenatal drugs, laboratory testing, protocols, ambulance and equipment.

Results

Eleven facilities comprising 6 hospitals (54.5 %), 4 polyclinics (36.4 %) and 1 health center were randomly sampled. Complete provider adherence to first antenatal guidelines for all the 946 participants was 48.1 % (95 % CI: 41.8–54.2 %), varying significantly amongst the types of facilities, with highest rate in the polyclinics. Average antenatal workload per month per clinical staff member was higher in polyclinics compared to the hospitals. All facility laboratories were able to conduct routine antenatal tests. Most routine antenatal drugs were available in all facilities except magnesium sulphate and sulphadoxine-pyrimethamine which were lacking in some. Antenatal service protocols and equipment were also available in all facilities.

Conclusion

Although antenatal workload varies across different facility types in the Greater Accra region, other health facility resources that support implementation of first antenatal care guidelines are equally available in all the facilities. These factors therefore do not adequately account for the low and varying proportions of complete adherence to guidelines across facility types. Providers should be continually engaged for a better understanding of the barriers to their adherence to these guidelines.

Effect of dietary antioxidant supplementation (Cuminum cyminum) on bacterial susceptibility of diabetes-induced rats

Diabetic patients are at risk of acquiring infections. Chronic low-grade inflammation is an important factor in the pathogenesis of diabetic complication. Diabetes causes generation of reactive oxygen species that increases oxidative stress, which may play a role in the development of complications as immune-deficiency and bacterial infection. The study aimed to investigate the role of a natural antioxidant, cumin, in the improvement of immune functions in diabetes. Diabetes was achieved by interperitoneal injection of streptozotocin (STZ). Bacterial infection was induced by application of Staphylococcus aureus suspension to a wound in the back of rats. The antioxidant was administered for 6 weeks. Results revealed a decrease in blood glucose levels in diabetic rats (p < 0.001), in addition to improving immune functions by decreasing total IgE approaching to the normal control level. Also, inflammatory cytokine (IL-6, IL-1β and TNF) levels, as well as total blood count decreased in diabetic rats as compared to the control group. Thus, cumin may serve as anti-diabetic treatment and may help in attenuating diabetic complications by improving immune functions. Therefore, a medical dietary antioxidant supplementation is important to improve the immune functions in diabetes.

Evaluation of a patient self-directed mealtime insulin titration algorithm: a US payer perspective

Objective To model the potential economic impact of implementing the AUTONOMY once daily (Q1D) patient self-titration mealtime insulin dosing algorithm vs standard of care (SOC) among a population of patients with Type 2 diabetes living in the US. Methods Three validated models were used in this analysis: The Treatment Transitions Model (TTM) was used to generate the primary results, while both the Archimedes (AM) and IMS Core Diabetes Models (IMS) were used to test the veracity of the primary results produced by TTM. Models used data from a 'real world' representative sample of patients (2012 US National Health and Nutrition Examination Survey) that matched the characteristics of US patients enrolled in the randomized controlled trial 'AUTONOMY' cohort. The base-case time horizon was 10 years. Results The modeling results from TTM demonstrated that total costs in the base-case were reduced by $1732, with savings predicted to occur as early as year 1. Results from the three models were consistent, showing a reduction in total costs for all sensitivity analyses. Limitations Data from short-term clinical trials were used to develop long-term projections. The nature of such extrapolation leads to increased uncertainty. Conclusion The results from all three models indicate that the AUTONOMY Q1D algorithm has the potential to abate total costs as early as the first year.

Incremental costs associated with myocardial infarction and stroke in patients with type 2 diabetes mellitus: an overview for economic modeling

OBJECTIVE

To identify cost estimates related to myocardial infarction (MI) or stroke in patients with type 2 diabetes mellitus (T2DM) for use in economic models.

METHODS

A systematic literature review was conducted. Electronic databases and conference abstracts were screened against inclusion criteria, which included studies performed in patients who had T2DM before experiencing an MI or stroke. Primary cost studies and economic models were included. Costs were converted to 2012 pounds sterling.

RESULTS

Fifty-four studies were identified: 13 primary cost studies and 41 economic evaluations using secondary sources for complication costs. Primary studies provided costs from 10 countries. Estimates for a fatal event ranged from £2482-£5222 for MI and from £4900-£6694 for stroke. Costs for the year a non-fatal event occurred ranged from £5071-£29,249 for MI and from £5171-£38,732 for stroke. Annual follow-up costs ranged from £945-£1616 for an MI and from £4704-£12,926 for a stroke. Economic evaluations from 12 countries were identified, and costs of complications showed similar variability to the primary studies.

DISCUSSION

The costs identified within primary studies varied between and within countries. Many studies used costs estimated in studies not specific to patients with T2DM. Data gaps included a detailed breakdown of resource use, which affected the ability to compare data across countries.

CONCLUSIONS

In the development of economic models for patients with T2DM, the use of accurate estimates of costs associated with MI and stroke is important. When country-specific costs are not available, clear justification for the choice of estimates should be provided.

Stratified patient-centered care in type 2 diabetes: a cluster-randomized, controlled clinical trial of effectiveness and cost-effectiveness

OBJECTIVE

Diabetes treatment should be effective and cost-effective. HbA1c-associated complications are costly. Would patient-centered care be more (cost-) effective if it was targeted to patients within specific HbA1c ranges?

RESEARCH DESIGN AND METHODS

This prospective, cluster-randomized, controlled trial involved 13 hospitals (clusters) in the Netherlands and 506 patients with type 2 diabetes randomized to patient-centered (n=237) or usual care (controls) (n=269). Primary outcomes were change in HbA1c and quality-adjusted life years (QALYs); costs and incremental costs (USD) after 1 year were secondary outcomes. We applied nonparametric bootstrapping and probabilistic modeling over a lifetime using a validated Dutch model. The baseline HbA1c strata were <7.0% (53 mmol/mol), 7.0-8.5%, and >8.5% (69 mmol/mol).

RESULTS

Patient-centered care was most effective and cost-effective in those with baseline HbA1c>8.5% (69 mmol/mol). After 1 year, the HbA1c reduction was 0.83% (95% CI 0.81-0.84%) (6.7 mmol/mol [6.5-6.8]), and the incremental cost-effectiveness ratio (ICER) was 261 USD (235-288) per QALY. Over a lifetime, 0.54 QALYs (0.30-0.78) were gained at a cost of 3,482 USD (2,706-4,258); ICER 6,443 USD/QALY (3,199-9,686). For baseline HbA1c 7.0-8.5% (53-69 mmol/mol), 0.24 QALY (0.07-0.41) was gained at a cost of 4,731 USD (4,259-5,205); ICER 20,086 USD (5,979-34,193). Care was not cost-effective for patients at a baseline HbA1c<7.0% (53 mmol/mol).

CONCLUSIONS

Patient-centered care is more valuable when targeted to patients with HbA1c>8.5% (69 mmol/mol), confirming clinical intuition. The findings support treatment in those with baseline HbA1c 7-8.5% (53-69 mmol/mol) and demonstrate little to no benefit among those with HbA1c<7% (53 mmol/mol). Further studies should assess different HbA1c strata and additional risk profiles to account for heterogeneity among patients.

Impact of therapy escalation on ambulatory care costs among patients with type 2 diabetes in France

BACKGROUND

This study compares annual ambulatory care expenditures per patient with type 2 diabetes mellitus (T2DM) in France according to treatment phase and renal function status.

METHODS

Records from patients with T2DM were extracted from a health insurance database. Patients were classified in subgroups, by treatment phase: oral/GLP1 monotherapy, double therapy, triple therapy or insulin therapy, and according to renal function status (identified using pharmacy, lab and consultation claims). Annual ambulatory expenditures were estimated from the national insurance perspective by year (from 2005 to 2010) and subgroup.

RESULTS

The number of patients ranged from 9,682 to 11,772 between 2005 and 2010. The average annual expenditure per individual in 2010 ranged from €3,017 (standard deviation: €3,829) for monotherapy to €3,609 ± €3,801 for triple therapy, and €7,398 ± €5,487 with insulin (adjusted ratio insulin therapy/monotherapy: 2.36, p < 0.001). Similar differences between treatement stages were found in previous years. Additional costs for insulin were mainly related to nursing care (multiplied by 18.42, p < 0.001), medical devices and pharmacy costs. DM-attributable drug costs were mainly related to antidiabetic drugs (28% for monotherapy to 71% for triple therapy), but also to cardiovascular system drugs (21% for monotherapy to 51% with insulin) and nervous system drugs (up to 8% with insulin). Declining renal function was associated with an increase in expenses by 12% to 53% according to treatment stage.

CONCLUSIONS

Overall, ambulatory care expenditures increase with treatment escalation and declining renal function amongst patients with T2DM. Insulin therapy is associated with substantially increased costs, related to pharmacy, nursing care and medical device costs.

Predicting costs of care in heart failure patients

BACKGROUND

Identifying heart failure patients most likely to suffer poor outcomes is an essential part of delivering interventions to those most likely to benefit. We sought a comprehensive account of heart failure events and their cumulative economic burden by examining patient characteristics that predict increased cost or poor outcomes.

METHODS

We collected electronic medical data from members of a large HMO who had a heart failure diagnosis and an echocardiogram from 1999-2004, and followed them for one year. We examined the role of demographics, clinical and laboratory findings, comorbid disease and whether the heart failure was incident, as well as mortality. We used regression methods appropriate for censored cost data.

RESULTS

Of the 4,696 patients, 8% were incident. Several diseases were associated with significantly higher and economically relevant cost changes, including atrial fibrillation (15% higher), coronary artery disease (14% higher), chronic lung disease (29% higher), depression (36% higher), diabetes (38% higher) and hyperlipidemia (21% higher). Some factors were associated with costs in a counterintuitive fashion (i.e. lower costs in the presence of the factor) including age, ejection fraction and anemia. But anemia and ejection fraction were also associated with a higher death rate.

CONCLUSIONS

Close control of factors that are independently associated with higher cost or poor outcomes may be important for disease management. Analysis of costs in a disease like heart failure that has a high death rate underscores the need for economic methods to consider how mortality should best be considered in costing studies.

Comparative analysis of single-species and polybacterial wound biofilms using a quantitative, in vivo, rabbit ear model

INTRODUCTION

The recent literature suggests that chronic wound biofilms often consist of multiple bacterial species. However, without appropriate in vivo, polybacterial biofilm models, our understanding of these complex infections remains limited. We evaluate and compare the effect of single- and mixed-species biofilm infections on host wound healing dynamics using a quantitative, in vivo, rabbit ear model.

METHODS

Six-mm dermal punch wounds in New Zealand rabbit ears were inoculated with Staphylococcus aureus strain UAMS-1, Pseudomonas aeruginosa strain PAO1, or both, totaling 10/6 colony-forming units/wound. Bacterial proliferation and maintenance in vivo were done using procedures from our previously published model. Wounds were harvested for histological measurement of wound healing, viable bacterial counts using selective media, or inflammatory cytokine (IL-1β, TNF-α) expression via quantitative reverse-transcription PCR. Biofilm structure was studied using scanning electron microscopy (SEM). For comparison, biofilm deficient mutant UAMS-929 replaced strain UAMS-1 in some mixed-species infections.

RESULTS

Bacterial counts verified the presence of both strains UAMS-1 and PAO1 in polybacterial wounds. Over time, strain PAO1 became predominant (p<0.001). SEM showed colocalization of both species within an extracellular matrix at multiple time-points. Compared to each monospecies infection, polybacterial biofilms impaired all wound healing parameters (p<0.01), and increased expression of IL-1β and TNF-α (p<0.05). In contrast, mixed-species infections using biofilm-deficient mutant UAMS-929 instead of wild-type strain UAMS-1 showed less wound impairment (p<0.01) with decreased host cytokine expression (p<0.01), despite a bacterial burden and distribution comparable to that of mixed-wild-type wounds.

CONCLUSIONS

This study reveals that mixed-species biofilms have a greater impact on wound healing dynamics than their monospecies counterparts. The increased virulence of polybacterial biofilm appears dependent on the combined pathogenicity of each species, verified using a mutant strain. These data suggest that individual bacterial species can interact synergistically within a single biofilm structure.

Quantitative comparison and analysis of species-specific wound biofilm virulence using an in vivo, rabbit-ear model

BACKGROUND

Although bacterial biofilm is recognized as an important contributor to chronic wound pathogenesis, differences in biofilm virulence between species have never been studied in vivo.

STUDY DESIGN

Dermal punch wounds in New Zealand white rabbit ears were inoculated with Klebsiella pneumoniae, Staphylococcus aureus, or Pseudomonas aeruginosa, or left uninfected as controls. In vivo biofilm was established and maintained using procedures from our previously published wound biofilm model. Virulence was assessed by measurement of histologic wound healing and host inflammatory mediators. Scanning electron microscopy (SEM) and bacterial counts verified biofilm viability. Extracellular polymeric substance (EPS)-deficient P aeruginosa was used for comparison.

RESULTS

SEM confirmed the presence of wound biofilm for each species. P aeruginosa biofilm-infected wounds showed significantly more healing impairment than uninfected, K pneumoniae, and S aureus (p < 0.05), while also triggering the largest host inflammatory response (p < 0.05). Extracellular polymeric substance-deficient P aeruginosa demonstrated a reduced impact on the same quantitative endpoints relative to its wild-type strain (p < 0.05).

CONCLUSIONS

Our novel analysis demonstrates that individual bacterial species possess distinct levels of biofilm virulence. Biofilm EPS may represent an integral part of their distinct pathogenicity. Rigorous examination of species-dependent differences in biofilm virulence is critical to developing specific therapeutics, while lending insight to the interactions within clinically relevant, polybacterial biofilms.

Stratifying healthcare costs using the Diabetes Complication Severity Index

OBJECTIVE

We aim to determine whether healthcare costs for patients diagnosed with Type 2 Diabetes Mellitus (T2DM) are associated with the severity of diabetes complications as measured by the Diabetes Complication Severity Index (DCSI).

METHODS

Retrospective cohort analysis was performed on a 2007 primary care cohort of T2DM patients. The DCSI is a 13-point scale, which comprises 7 categories of complications and their severity levels. Healthcare cost data from 2008 and 2009 were used as primary outcome. Inpatient and outpatient costs incurred for services consumed by patients within the provider network were included. Generalized linear model with log-link and gamma distribution was used to predict healthcare costs.

RESULTS

Of the 59,767 T2DM patients, 2977 (5.0%) deaths occurred and 1336 (2.2%) were lost to follow up. Healthcare cost was strongly associated with increase in DCSI score. Compared to patients without complications, those with more complications (higher DCSI score) had an increased risk of higher healthcare costs. Risk ratio (RR) increased from 1.25 (95%CI: 1.19-1.32) for DCSI=1 to 1.61 (1.51-1.72) for DCSI=2; 2.10 (1.91-2.31) for DCSI=3; 2.52 (2.21-2.87) for DCSI=4 and 3.62 (3.09-4.25) for DCSI≥5. As a continuous score, a one-point increase in the DCSI was associated with a cost increase of 27% (95%CI: 1.25-1.29).

CONCLUSION

The DCSI score is a useful tool for predicting direct healthcare costs. The DCSI can be used to triage high-risk patients for more focused secondary prevention interventions at primary care level, in a bid to lower overall healthcare costs.

Significant J-shaped association between body mass index (BMI) and diabetic foot ulcers

BACKGROUND

Disagreement exists regarding the relationship between body weight and foot ulceration risk among diabetic persons.

METHODS

We used a nested case-control design to estimate the association between body mass index (BMI) and 1-year and 5-year foot ulceration risk. We obtained data on all diabetic patients < 60 years of age who were treated in the US Department of Veterans Affairs healthcare system in 2003. Patient characteristics and co-morbidities were obtained at baseline. For each individual with an incident foot ulcer (case), up to four individuals were randomly selected who matched the case on age, sex, race, marital status, and calendar time.

RESULTS

Crude 1-year and 5-year incidence rates were 1.35 and 6.22% after a mean follow-up of 11.8 ± 1.2 months and 55.5 ± 12.8 months, respectively. Compared with individuals with BMI 25-29.9 kg/m(2) , those with BMI 40-44.9 kg/m(2) and those with BMI ≥ 45 kg/m(2) had 25% [adjusted odds ratio (AOR) = 1.25; 95% confidence interval (CI), 1-1.56] and 83% (AOR = 1.83; 95% CI, 1.44-2.32) higher 1-year risk and 1.4 (AOR = 1.39; 95% CI, 1.26-1.54) and 2.1 (AOR = 2.08; 95% CI, 1.86-2.32) times higher 5-year risk. BMI < 25 kg/m(2) was associated with 30% higher risk at both 1 year (AOR = 1.28; 95% CI, 1.04-1.58) and 5 years (AOR = 1.27; 95% CI, 1.15-1.40).

CONCLUSIONS

Our data suggest a significant J-shaped association between BMI and diabetic foot ulcers.

Disability and cost for diabetic patients at a public district hospital in Thailand

OBJECTIVE

The study determined the rate of disability among diabetic patients at a public district hospital in Thailand and compared the costs of illness among different levels of severity of disability. This was the first such study carried out in Thailand.

METHODS

The study was conducted at Waritchaphum Hospital in northeastern Thailand. Data were collected from 475 randomly selected diabetic patients identified by the World Health Organization's International Classification of Diseases, tenth revision (ICD-10 codes E10 - E14) who received treatment from the study hospital during the fiscal year of 2008. The disability levels were determined by using Thailand ministerial guidelines as well as the Barthel index score. Cost-of-illness estimates followed the prevalence-based approach and it presented the societal perspective of cost-of-illness of diabetes in 2008.

KEY FINDINGS

The study results showed that 9.68% of the study participants had physical impairment while 9.26% had impairment in eyesight. The Barthel index score showed that 13.5% of the study participants were disabled. When comparing costs between independent and disabled persons, considering the Barthel index score, average costs for the disabled diabetic persons were significantly higher than for those who were independent (US$2700.29 versus 598.24; P<0.001).

CONCLUSIONS

The study concluded that the presence of complications and disability among diabetic patients impacts severely on Thai society. At present, the Thai government allocates US$187.5 per annum to registered disabled persons as a disability living allowance. The study found a large difference between the direct economic outlay of the patients and the allowance provided, which suggests that there is probably a need to revise the welfare payment upwards.

Diagnostic accuracy of existing methods for identifying diabetic foot ulcers from inpatient and outpatient datasets

BACKGROUND

As the number of persons with diabetes is projected to double in the next 25 years in the US, an accurate method of identifying diabetic foot ulcers in population-based data sources are ever more important for disease surveillance and public health purposes. The objectives of this study are to evaluate the accuracy of existing methods and to propose a new method.

METHODS

Four existing methods were used to identify all patients diagnosed with a foot ulcer in a Department of Veterans Affairs (VA) hospital from the inpatient and outpatient datasets for 2003. Their electronic medical records were reviewed to verify whether the medical records positively indicate presence of a diabetic foot ulcer in diagnoses, medical assessments, or consults. For each method, five measures of accuracy and agreement were evaluated using data from medical records as the gold standard.

RESULTS

Our medical record reviews show that all methods had sensitivity > 92% but their specificity varied substantially between 74% and 91%. A method used in Harrington et al. (2004) was the most accurate with 94% sensitivity and 91% specificity and produced an annual prevalence of 3.3% among VA users with diabetes nationwide. A new and simpler method consisting of two codes (707.1× and 707.9) shows an equally good accuracy with 93% sensitivity and 91% specificity and 3.1% prevalence.

CONCLUSIONS

Our results indicate that the Harrington and New methods are highly comparable and accurate. We recommend the Harrington method for its accuracy and the New method for its simplicity and comparable accuracy.

In vitro multispecies Lubbock chronic wound biofilm model

Multispecies biofilms are becoming increasingly recognized as the naturally occurring state in which bacteria reside. One of the primary health issues that is now recognized to be exacerbated by biofilms are chronic, nonhealing wounds such as venous leg ulcers, diabetic foot ulcers, and pressure ulcers. Arguably three of the most important species associated with multispecies biofilms that our group sees clinically are Pseudomonas aeruginosa, Enterococcus faecalis, and Staphylococcus aureus. This study was conducted to address the need for a chronic pathogenic biofilm laboratory model that allows for cooperative growth of these three organisms. We have developed a novel media formulation, simple laboratory system, quantitative polymerase chain reaction for monitoring population dynamics, and methods for objectively and subjectively measuring biofilm formation. The Lubbock chronic wound pathogenic biofilm withstood treatment with a 50-fold higher concentration of bleach than that which was completely bacteriocidal for fully turbid planktonic cultures. The Lubbock chronic wound pathogenic biofilm when treated with biofilm effectors such as gallium nitrate and triclosan responded with selective inhibition of Pseudomonas aeruginosa or Staphylococcus aureus, respectively, as has been reported in the literature. The ability of this 24-hour model to react as predicted using known biofilm effectors suggests that it will lend itself to future work in the development and testing of first-generation chronic wounds pathogenic biofilm therapeutics. We have defined a realistic in vitro multispecies biofilm model simulating the functional characteristics of chronic pathogenic biofilms and developed effective tools for its characterization and analyses.

Costs of stroke using patient-level data: a critical review of the literature

BACKGROUND AND PURPOSE

With decision-analytic models becoming more popular to assess the cost-effectiveness of health care interventions, the need for robust estimates on the costs of cerebrovascular disease is paramount. This study reports the results from a literature review of the costs of cerebrovascular diseases, and assesses the quality of the published evidence against a set of defined criteria.

METHODS

A broad literature search was conducted. Those studies reporting mean/median costs of cerebrovascular diseases derived from patient-level data in a developed country setting were included. Data were abstracted using standardized reporting forms and assessed against 4 predefined criteria: use of adequate methodologies, use of a population-based study, inclusion of premorbid resource use, and reporting of costs by different patient subgroups.

RESULTS

A total of 120 cost studies were identified. The cost estimates of stroke were compared by taking into account the effects of inflation and price differentials between countries. Average costs of stroke ranged from $468 to $146 149. Differences in costs were also found within country, with estimates in the USA varying 20-fold. Although the costing methodologies used were generally appropriate, only 5 studies were based on population-based studies, which are the gold standard study design when comparing incidence, outcome, and costs.

CONCLUSIONS

This review showed large variations in the costs of stroke, mainly attributable to differences in the populations studied, methods, and cost categories included. The wide range of cost estimates could lead to selection bias in secondary health economic analyses, with authors including those costs that are more likely to produce the desired results.

Defects in innate immunity predispose C57BL/6J-Leprdb/Leprdb mice to infection by Staphylococcus aureus

Foot and ankle infections are the most common cause of hospitalization among diabetic patients, and Staphylococcus aureus is a major pathogen implicated in these infections. Patients with insulin-resistant (type 2) diabetes are more susceptible to bacterial infections than nondiabetic subjects, but the pathogenesis of these infections is poorly understood. C57BL/6J-Lepr(db)/Lepr(db) (hereafter, db/db) mice develop type 2 diabetes due to a recessive, autosomal mutation in the leptin receptor. We established a S. aureus hind paw infection in diabetic db/db and nondiabetic Lepr(+/+) (+/+) mice to investigate host factors that predispose diabetic mice to infection. Nondiabetic +/+ mice resolved the S. aureus hind paw infection within 10 days, whereas db/db mice with persistent hyperglycemia developed a chronic infection associated with a high bacterial burden. Diabetic db/db mice showed a more robust neutrophil infiltration to the infection site and higher levels of chemokines in the infected tissue than +/+ mice. Blood from +/+ mice killed S. aureus in vitro, whereas db/db blood was defective in bacterial killing. Compared with peripheral blood neutrophils from +/+ mice, db/db neutrophils demonstrated a diminished respiratory burst when stimulated with S. aureus. However, bone marrow-derived neutrophils from +/+ and db/db mice showed comparable phagocytosis and bactericidal activity. Our results indicate that diabetic db/db mice are more susceptible to staphylococcal infection than their nondiabetic littermates and that persistent hyperglycemia modulates innate immunity in the diabetic host.

Polymicrobial nature of chronic diabetic foot ulcer biofilm infections determined using bacterial tag encoded FLX amplicon pyrosequencing (bTEFAP)

BACKGROUND

Diabetic extremity ulcers are associated with chronic infections. Such ulcer infections are too often followed by amputation because there is little or no understanding of the ecology of such infections or how to control or eliminate this type of chronic infection. A primary impediment to the healing of chronic wounds is biofilm phenotype infections. Diabetic foot ulcers are the most common, disabling, and costly complications of diabetes. Here we seek to derive a better understanding of the polymicrobial nature of chronic diabetic extremity ulcer infections.

METHODS AND FINDINGS

Using a new bacterial tag encoded FLX amplicon pyrosequencing (bTEFAP) approach we have evaluated the bacterial diversity of 40 chronic diabetic foot ulcers from different patients. The most prevalent bacterial genus associated with diabetic chronic wounds was Corynebacterium spp. Findings also show that obligate anaerobes including Bacteroides, Peptoniphilus, Fingoldia, Anaerococcus, and Peptostreptococcus spp. are ubiquitous in diabetic ulcers, comprising a significant portion of the wound biofilm communities. Other major components of the bacterial communities included commonly cultured genera such as Streptococcus, Serratia, Staphylococcus and Enterococcus spp.

CONCLUSIONS

In this article, we highlight the patterns of population diversity observed in the samples and introduce preliminary evidence to support the concept of functional equivalent pathogroups (FEP). Here we introduce FEP as consortia of genotypically distinct bacteria that symbiotically produce a pathogenic community. According to this hypothesis, individual members of these communities when they occur alone may not cause disease but when they coaggregate or consort together into a FEP the synergistic effect provides the functional equivalence of well-known pathogens, such as Staphylococcus aureus, giving the biofilm community the factors necessary to maintain chronic biofilm infections. Further work is definitely warranted and needed in order to prove whether the FEPs concept is a viable hypothesis. The findings here also suggest that traditional culturing methods may be extremely biased as a diagnostic tool as they select for easily cultured organisms such as Staphylococcus aureus and against difficult to culture bacteria such as anaerobes. While PCR methods also have bias, further work is now needed in comparing traditional culture results to high-resolution molecular diagnostic methods such as bTEFAP.

Resource use and costs of type 2 diabetes in Sweden - estimates from population-based register data

AIMS

To examine medical resource use of Swedish patients with type 2 diabetes during 2000-2004 and to estimate annual costs of care.

METHODS

Retrospective population-based cohort study of patients with type 2 diabetes identified in computerised medical records at 26 primary care centres in Uppsala county, Sweden. Annual quantities of medical resources were determined for prevalent cases during 2000-2004 using register data from outpatient primary care, outpatient hospital care, the National Inpatient Register and a national register for treatment of uraemia. Average costs of care of patients with type 2 diabetes were estimated based on year 2004 resource quantities of 8230 prevalent study cases.

RESULTS

Annual quantities of medical resource use were stable in outpatient primary care and outpatient hospital care, with patients making an average of two General Practitioner visits and 3.5 outpatient hospital visits each year. Higher rates of hospitalisation [12% in 2000 (n = 6711) compared with 16% in 2004 (n = 8230)] led to an increase in the mean (SD) number of inpatient days from 2.3 (11.8) to 2.7 (11.9) (p = 0.040) between 2000 and 2004. Mean (SD) total costs of care in 2004 were EUR 3602 (EUR 9537). Inpatient care was the major contributor to costs, accounting for 57% of total costs while drug costs accounted for an average 7%.

CONCLUSIONS

Swedish type 2 diabetic patients in this large sample from Uppsala county required steady annual amounts of outpatient care and increasing amounts of inpatient care during 2000-2004. The associated costs in 2004 were substantial, with inpatient care identified as the most important component.

Survey of bacterial diversity in chronic wounds using pyrosequencing, DGGE, and full ribosome shotgun sequencing

BACKGROUND

Chronic wound pathogenic biofilms are host-pathogen environments that colonize and exist as a cohabitation of many bacterial species. These bacterial populations cooperate to promote their own survival and the chronic nature of the infection. Few studies have performed extensive surveys of the bacterial populations that occur within different types of chronic wound biofilms. The use of 3 separate16S-based molecular amplifications followed by pyrosequencing, shotgun Sanger sequencing, and denaturing gradient gel electrophoresis were utilized to survey the major populations of bacteria that occur in the pathogenic biofilms of three types of chronic wound types: diabetic foot ulcers (D), venous leg ulcers (V), and pressure ulcers (P).

RESULTS

There are specific major populations of bacteria that were evident in the biofilms of all chronic wound types, including Staphylococcus, Pseudomonas, Peptoniphilus, Enterobacter, Stenotrophomonas, Finegoldia, and Serratia spp. Each of the wound types reveals marked differences in bacterial populations, such as pressure ulcers in which 62% of the populations were identified as obligate anaerobes. There were also populations of bacteria that were identified but not recognized as wound pathogens, such as Abiotrophia para-adiacens and Rhodopseudomonas spp. Results of molecular analyses were also compared to those obtained using traditional culture-based diagnostics. Only in one wound type did culture methods correctly identify the primary bacterial population indicating the need for improved diagnostic methods.

CONCLUSION

If clinicians can gain a better understanding of the wound's microbiota, it will give them a greater understanding of the wound's ecology and will allow them to better manage healing of the wound improving the prognosis of patients. This research highlights the necessity to begin evaluating, studying, and treating chronic wound pathogenic biofilms as multi-species entities in order to improve the outcomes of patients. This survey will also foster the pioneering and development of new molecular diagnostic tools, which can be used to identify the community compositions of chronic wound pathogenic biofilms and other medical biofilm infections.

Multi-site testing with a point-of-care nerve conduction device can be used in an algorithm to diagnose diabetic sensorimotor polyneuropathy

OBJECTIVE

We aimed to establish whether multi-nerve testing with a point-of-care nerve conduction device could be used to diagnose diabetic sensorimotor polyneuropathy.

RESEARCH DESIGN AND METHODS

A total of 72 consecutive patients with diabetes underwent a full neurological examination and a concurrent evaluation for nine standard electrophysiological parameters using conventional nerve conduction studies (the reference standard) and a point-of-care device.

RESULTS

Spearman coefficients for correlation of point-of-care and conventional parameters ranged between 0.76 and 0.91 (P < 0.001 in all comparisons). Agreement by the method of Bland and Altman was acceptable despite small systematic biases. Fifty subjects (69%) had neuropathy according to conventional criteria. The sensitivity and specificity for the point-of-care device to identify such neuropathy was 88 and 82%, respectively.

CONCLUSIONS

A novel point-of-care device has reasonable diagnostic accuracy and thus may represent a sufficiently accurate alternative for detecting the diffuse electrophysiological criteria necessary to make the diagnosis of diabetic sensorimotor polyneuropathy.

Economic impact of cardiovascular co-morbidity in patients with type 2 diabetes

OBJECTIVES

To evaluate the impact of cardiovascular co-morbidity on total and diabetes-related healthcare costs in patients with type 2 diabetes.

METHODS

Retrospective analysis of the West Virginia state Medicaid claims data was conducted in patients with type 2 diabetes (ICD-9 codes: 250.0x-250.9x, where x=0 or 2) in the year 2001. Patients > or =65 years of age or those with managed care coverage were excluded. Presence of cardiovascular co-morbidity in the year 2001 was identified. Semi-logarithmic regression models were used to estimate the impact of cardiovascular co-morbidity on total and diabetes-related healthcare costs in the year 2002.Two-part models were used to study the impact of cardiovascular co-morbidity on ER/hospitalization, outpatient, and prescription costs. Smearing estimates were used to interpret the results from the semi-logarithmic models.

RESULTS

Presence of cardiovascular co-morbidity had a significant impact on all categories of total and diabetes-related healthcare costs, except diabetes-related prescription drug costs. Type 2 diabetes patients with cardiovascular co-morbidity had significantly higher total healthcare costs (38.9%, $12,550 vs. $9031), total ER/hospitalization costs (239.8%, $4845 vs. $1426), total outpatient costs (35.3%, $3956 vs. $2925), and total prescription drug costs (15.1%, $4686 vs. $4071) compared to those without cardiovascular co-morbidity. Similarly, type 2 diabetes patients with cardiovascular co-morbidity had significantly higher total diabetes-related healthcare costs (59.7%, $4349 vs. $2724), ER/hospitalization costs (346.8%, $1911 vs. $428), and outpatient costs (17.4%, $740 vs. $631) compared to patients without cardiovascular co-morbidity.

CONCLUSIONS

Presence of cardiovascular co-morbidity in patients with type 2 diabetes had a significant impact on total and diabetes-related healthcare costs.

[The cost of complications: implications for the measurement of the cost of type II diabetes mellitus]

BACKGROUND

A well-known methodology used to compute the macroeconomic cost of risk factors is the etiologic cost ratio, leading to estimates based on data on the prevalence of the risk factor in the general population, the relative risk of complications associated to it and the cost of the complications. A major problem of this method is that it is in some extent inconsistent with recent findings showing an increase in the per capita cost of some complications in presence of type II diabetes mellitus. The aim of the paper is to reconcile the approach with most recent economic studies and to overview the consequences of such an attempt in terms of methodological framework.

METHODS

We developed a methodological framework introducing heterogeneity in the cost of treating complications according to the presence of diabetes. We estimated the macroeconomic cost of type II diabetes mellitus based on selected complications (stroke, myocardial infarction, nephropathy and peripheral arterial obstructive disease) from French representative data in two situations: a situation in which the heterogeneity is not taken into account, another situation in which heterogeneity is introduced.

RESULTS

Our results point out that the assumption of homogeneity in the cost of complications is associated to an underestimation of the cost of diabetes by about 30%.

CONCLUSION

Our results present an attempt to reconcile the economic modeling of the cost of type II diabetes mellitus with the "real world". We conclude that the introduction of heterogeneity is necessary to capture the whole extent of the economic burden of the disease and that it places significant constraints on the data and the methodological framework to be used in such attempts.

Validation of a novel point-of-care nerve conduction device for the detection of diabetic sensorimotor polyneuropathy

OBJECTIVE

The diagnosis of diabetic sensorimotor polyneuropathy using objective electrophysiological tests is hindered by limited access to the specialized laboratories and technicians that perform and interpret them. We evaluated the performance characteristics of a novel portable and automated point-of-care nerve conduction study device, which can be operated by nontechnical personnel, and compared it with conventional nerve conduction studies performed in a specialist setting.

RESEARCH DESIGN AND METHODS

Seventy-two consecutive patients with diabetes (8 type 1, 64 type 2) from a diabetes and a neuropathy outpatient clinic were evaluated concurrently with conventional nerve conduction studies (the reference standard) and the point-of-care device for sural nerve function (sural nerve amplitude potentials in microvolts [microV]).

RESULTS

Sural nerve amplitude potentials measured by the point-of-care device shared very strong correlation with the reference standard (Spearman's correlation coefficient 0.95, P < 0.001). The Bland and Altman method yielded agreement despite a small systematic underestimation by the point-of-care device of 1.2 +/- 3.4 microV. Despite this small systematic bias, the sensitivity and specificity of normal and abnormal sural nerve amplitude potentials measured by the point-of-care device for the detection of diabetic sensorimotor polyneuropathy defined by standard clinical and electrophysiological criteria were 92 and 82%, respectively.

CONCLUSIONS

A novel point-of-care device has excellent diagnostic accuracy for detecting electrophysiological abnormality in the sural nerve of patients who have diabetes. This automated device represents an alternative to conventional nerve conduction studies for the diagnosis of diabetic sensorimotor polyneuropathy.

What Is the Future of Diabetic Wound Care?

With diabetes affecting 5% to 10% of the US population, development of a more effective treatment for chronic diabetic wounds is imperative. Clinically, the current treatment in topical wound management includes debridement, topical antibiotics, and a state-of-the-art topical dressing. State-of-the-art dressings are a multi-layer system that can include a collagen cellulose substrate, neonatal foreskin fibroblasts, growth factor containing cream, and a silicone sheet covering for moisture control. Wound healing time can be up to 20 weeks. The future of diabetic wound healing lies in the development of more effective artificial "smart" matrix skin substitutes. This review article will highlight the need for novel smart matrix therapies. These smart matrices will release a multitude of growth factors, cytokines, and bioactive peptide fragments in a temporally and spatially specific, event-driven manner. This timed and focal release of cytokines, enzymes, and pharmacological agents should promote optimal tissue regeneration and repair of full-thickness wounds. Development of these kinds of therapies will require multidisciplinary translational research teams. This review article outlines how current advances in proteomics and genomics can be incorporated into a multidisciplinary translational research approach for developing novel smart matrix dressings for ulcer treatment. With the recognition that the research approach will require both time and money, the best treatment approach is the prevention of diabetic ulcers through better foot care, education, and glycemic control.

The pathogenesis of Staphylococcus aureus infection in the diabetic NOD mouse

Although Staphylococcus aureus is a major pathogen implicated in diabetic foot infections, little is known about the pathogenesis of this disease. A model of S. aureus infection in the hindpaw of nonobese diabetic (NOD) mice was developed. The experimental infection was exacerbated in diabetic mice (blood glucose levels > or =19 mmol/l) compared with nondiabetic mice, and the diabetic animals were unable to clear the infection over a 10-day period. Insulin-mediated control of glycemia in diabetic mice resulted in enhanced clearance of S. aureus from the infected tissue. Diabetic mice showed reduced tissue inflammation in response to bacterial inoculation compared with nondiabetic NOD animals, and this was consistent with the novel finding of significantly decreased tissue levels of the chemokines KC and MIP-2 in diabetic mice. Blood from nondiabetic and diabetic NOD mice killed S. aureus in vitro, whereas the bacteria multiplied in blood from diabetic mice with severe hyperglycemia. The impaired killing of S. aureus by diabetic mice was correlated with a diminished leukocytic respiratory burst in response to S. aureus in blood from diabetic animals. This animal model of hindpaw infection may be useful for the analysis of host defects in innate immunity that contribute to recalcitrant diabetic foot infections.

The cost of medical care for patients with diabetes, hypertension and both conditions: does alcohol use play a role?

OBJECTIVE

To estimate and compare the medical costs of individuals with diabetes and/or hypertension relative to a matched sample of individuals with neither condition, and determine if these costs are significantly influenced by alcohol use.

RESEARCH DESIGN AND METHODS

Data were obtained from a sample of 799 patients from eight primary care clinics in south-central Wisconsin between 2001 and 2002. Medical care costs were calculated within four categories [hospital and emergency room (ER) costs, clinic costs, medication costs and total cost] for three chronic disease samples [diabetes only (n = 89), hypertension only (n = 299), and both diabetes and hypertension (n = 209)] as well as a matched sample with neither diabetes nor hypertension (n = 202). Annual medical care costs were estimated using a combination of insurance billing records, self-reported information and chart review. All cost data pertain to a 12-month period in 2001-2002. In addition to a descriptive analysis of costs across medical service categories and samples, we also conducted multivariate analyses of total cost, controlling for patient demographics, education, employment, smoking, and comorbidities, such as heart disease, hyperlipidaemia, liver disease, chronic back pain, asthma, depression, anxiety and bronchitis.

RESULTS

The estimated differential in total annual medical cost (relative to the control group) was USD 2183 for diabetes only, USD 724 for hypertension only and USD 3402 for diabetes and hypertension. Alcohol use did not significantly impact medical care costs amongst individuals with diabetes and/or hypertension.

CONCLUSIONS

These cost estimates can serve as an important and useful reference source for doctors, insurance companies, health maintenance organizations (HMOs) and policy makers as they try to anticipate the future medical care needs and associated costs for diabetic and hypertensive patients.

Hospitalizations, nursing home admissions, and deaths attributable to diabetes

OBJECTIVE

To estimate all-cause hospitalizations, nursing home admissions, and deaths attributable to diabetes using a new methodology based on longitudinal data for a representative sample of older U.S. adults.

RESEARCH DESIGN AND METHODS

A simulation model, based on data from the National Health and Nutrition Examination Survey (NHANES) I Epidemiologic Followup Study, was used to represent the natural history of diabetes and control for a variety of baseline risk factors. The model was applied to 6,265 NHANES III adults aged 45-74 years. The prevalence of risk factors in NHANES III, fielded in 1988-1994, better represents today's adults.

RESULTS

For all NHANES III adults aged 45-74 years, a diagnosis of diabetes accounted for 8.6% of hospitalizations, 12.3% of nursing home admissions, and 10.3% of deaths in 1988-1994. For people with diabetes, diabetes alone was responsible for 43.4% of hospitalizations, 52.1% of nursing home admissions, and 47% of deaths. Adjusting for related cardiovascular conditions, which may provide more accurate estimates of attributable risks for people with diabetes, increased these estimates to 51.4, 57.1, and 56.8%, respectively.

CONCLUSIONS

Risks of institutionalization and death attributable to diabetes are large. Efforts to translate recent trials of primary prevention into practice and continued efforts to prevent complications of diabetes could have a substantial impact on hospitalizations, nursing home admissions, and deaths and their societal costs.

The costs of type 2 diabetes mellitus in Italy: a CODE-2 sub-study

AIM

To estimate the direct, indirect, and intangible costs associated with type 2 diabetes mellitus in Italy in 1998. To evaluate the economic impact of diabetic complications, and to investigate drug treatment patterns and associated costs in patients with type 2 diabetes.

METHODS

The Italian arm of an international study (COsts of Diabetes in Europe--Type 2 [CODE-2], a descriptive, cross-sectional survey) was set up to collect information retrospectively by means of questionnaires from a sample of 1263 patients. Resource use was measured in monetary terms using a set of costs and tariffs. Intangible costs were estimated using the EuroQol questionnaire.

RESULTS

The average yearly cost for medical resources for a patient with type 2 diabetes was 2991 Euro, whereas the estimated cost for the whole population with type 2 diabetes was about 5170 million Euro. This corresponds to 6.65% of the total healthcare expenditure (public and private) in Italy. Of direct costs, 29% was spent for the treatment of diabetes and 39% for the treatment of diabetic complications; while the remaining 32% was spent for healthcare not related to diabetes. Quality of life score in patients with type 2 diabetes (EuroQoL overall average score) was 0.68.

CONCLUSIONS

Type 2 diabetes has a high cost to society. The major cost component is due to the care of diabetic complications, not to the treatment of the illness itself; in particular, drug costs represent a relatively small proportion of such treatment cost.

Cost analysis of human islet transplantation for the treatment of type 1 diabetes in the Swiss-French Consortium GRAGIL

OBJECTIVE

To evaluate the cost of islet transplantation in type 1 diabetic patients with a functional renal graft in a multicenter network.

RESEARCH DESIGN AND METHODS

The study involved nine diabetic patients transplanted in the Swiss-French Groupe Rhône-Alpes, Rhin et Geneve pour la transplantation d'Ilots Langerhans (GRAGIL) consortium between March 1999 and June 2000. The direct medical costs were estimated from Social Security's perspective from the inclusion of the patient to 1 year after transplantation. All cost components were computed separately and included evaluation, screening and candidacy, organ retrieval, islet processing, pancreas and islet transportation, hospitalization for transplantation, follow-up, medications (immunosuppressive, antidiabetic, and adjuvant drugs), and adverse events requiring hospitalization.

RESULTS

During the study period, 56 pancreata were processed and 14 islet preparations were transplanted. The average cost of an islet transplantation (procedure and 1-year follow-up) was 77,745 euro (French rate, year 2000). The four main cost components were islet preparation (30% of the total cost), adverse events (24%), drugs (14%), and hospitalization (13%).

CONCLUSIONS

Overall costs of islet transplantation are slightly higher than those of pancreas transplantation. The cell isolation process is a critical point; a reduction in overall cost will require more efficient ways of isolating high yields of viable islets. Costs generated by shipments within the GRAGIL network did not represent an economic burden. It can be expected that the costs will decrease with growing experience and improving technology.

Community exercise program use and changes in healthcare costs for older adults

BACKGROUND

Regular exercise is associated with many health benefits. Community-based exercise programs may increase exercise participation, but little is known about cost implications.

METHOD

A retrospective, matched cohort study was conducted to determine if changes in healthcare costs for Medicare-eligible adults who choose to participate in a community-based exercise program were different from similar individuals who did not participate. Exercise program participants included 1114 adults aged > or = 65 years, who were continuously enrolled in Group Health Cooperative of Puget Sound (GHC) between October 1, 1997 and December 31, 2000 and who participated in the Lifetime Fitness (exercise) Program Copyright (LFP) at least once; three GHC enrollees who never attended LFP were randomly selected as controls for each participant by matching on age and gender. Cost and utilization estimates from GHC administrative data for the time from LFP enrollment to December 31, 2000 were compared using multivariable regression models.

RESULTS

The average increase in annual total healthcare costs was less in participants compared to controls (+642 dollars vs +1175 dollars; p=0.05). After adjusting for differences in age, gender, enrollment date, comorbidity index, and pre-exposure cost and utilization levels, total healthcare costs for participants were 94.1% (95% confidence interval [CI], 85.6%-103.5%) of control costs. However, for participants who attended the exercise program at an average rate of > or = 1 visit weekly, total adjusted follow-up costs were 79.3% (95% CI, 71.3%-88.2%) of controls.

CONCLUSIONS

Including a community exercise program as a health insurance benefit shows promise as a strategy for helping some Medicare-eligible adults to improve their health through exercise.

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.

The impact of diabetes-related complications on healthcare costs: results from the United Kingdom Prospective Diabetes Study (UKPDS Study No. 65)

AIMS

To develop a model for estimating the immediate and long-term healthcare costs associated with seven diabetes-related complications in patients with Type 2 diabetes participating in the UK Prospective Diabetes Study (UKPDS).

METHODS

The costs associated with some major complications were estimated using data on 5102 UKPDS patients (mean age 52.4 years at diagnosis). In-patient and out-patient costs were estimated using multiple regression analysis based on costs calculated from the length of admission multiplied by the average specialty cost and a survey of 3488 UKPDS patients' healthcare usage conducted in 1996-1997.

RESULTS

Using the model, the estimate of the cost of first complications were as follows: amputation pound 8459 (95% confidence interval pound 5295, pound 13 200); non-fatal myocardial infarction pound 4070 ( pound 3580, pound 4722); fatal myocardial infarction pound 1152 ( pound 941, pound 1396); fatal stroke pound 3383 ( pound 1935, pound 5431); non-fatal stroke pound 2367 ( pound 1599, pound 3274); ischaemic heart disease pound 1959 ( pound 1467, pound 2541); heart failure pound 2221 ( pound 1690, pound 2896); cataract extraction pound 1553 ( pound 1320, pound 1855); and blindness in one eye pound 872 ( pound 526, pound 1299). The annual average in-patient cost of events in subsequent years ranged from pound 631 ( pound 403, pound 896) for heart failure to pound 105 ( pound 80, pound 142) for cataract extraction. Non-in-patient costs for macrovascular complications were pound 315 ( pound 247, pound 394) and for microvascular complications were pound 273 ( pound 215, pound 343) in the year of the event. In each subsequent year the costs were, respectively, pound 258 ( pound 228, pound 297) and pound 204 ( pound 181, pound 255).

CONCLUSIONS

These results provide estimates of the immediate and long-term healthcare costs associated with seven diabetes-related complications.

Treatment of onychomycosis in the diabetic patient population

Onychomycosis is a common medical condition in patients with diabetes. Conflicting data exist as to whether diabetes predisposes patients to the disease. Controversy notwithstanding, patients with diabetes have several medical conditions (obesity, peripheral neuropathy, and retinopathy) that can inhibit the identification or mask the progression of fungal nail infections. In addition, vascular insufficiency, impaired wound healing, and compromised immunologic status associated with diabetic foot increase the risk of secondary infections in diabetic patients with onychomycosis. Such factors contribute to an increased morbidity and decreased quality of life in these patients and underscore the need for effective antifungal treatment. Oral antifungal agents are generally well tolerated, but serious adverse events independent of or associated with a number of significant drug interactions have been reported. The availability of a topical therapy, ciclopirox topical solution, 8% (Penlac Nail Lacquer), provides clinicians with an additional effective and well-tolerated treatment option. In order to further increase the efficacy of topical or oral treatment, mechanical intervention (e.g., debridement) may be combined with either of these options. Choice of appropriate treatment and careful monitoring of fungal nail infections can prevent significant morbidity in patients with diabetes.

Estimates of direct medical costs for microvascular and macrovascular complications resulting from type 2 diabetes mellitus in the United States in 2000

BACKGROUND

Diabetes mellitus is a chronic condition that affects the health of Americans and the US health care system on many levels. According to the American Diabetes Association, approximately 16 million Americans have diabetes mellitus. The onset of type 2 diabetes mellitus, which accounts for the vast majority (90%-95%) of cases, precedes diagnosis by a mean 7 years, with the disease typically manifesting during adulthood. It is not uncommon for people to first realize they have diabetes mellitus due to the appearance of a related complication.

OBJECTIVE

The goal of this analysis was to estimate the direct medical costs of managing microvascular and macrovascular complications of type 2 diabetes mellitus in the United States in the year 2000.

METHODS

Complication costs were estimated by applying unit costs to typical resource-use profiles. A combination of direct data analysis and cost modeling was used. For each complication, the event costs referred to those associated with the acute episode and subsequent care in the first year. State costs were the annual costs of continued management. Data were obtained from many sources, including inpatient, ambulatory, and emergency department care databases from several states; national physician and laboratory fee schedules; government reports; and literature. All costs were expressed in 2000 US dollars.

RESULTS

Major events (eg, acute myocardial infarction--30,364 dollars event cost, 1678 dollars state cost) generated a greater financial burden than early-stage complica- tions (eg, microalbuminuria--63 dollars event cost, 15 dollars state cost). However, complications that were initially relatively low in cost (eg, microalbuminuria) can progress to more costly advanced stages (eg, end-stage renal disease--37,022 dollars state cost).

CONCLUSIONS

Given the scope of diabetes mellitus in the United States and its impact on health care and budgets, it is important for policy makers to have up-to-date information about treatment outcomes and costs. The costs presented here provide essential components for any analysis examining the economic burden of the complications of diabetes mellitus.