Burden of Infected Diabetic Foot Ulcers on Hospital Admissions and Costs

doi:10.1016/j.avsg.2015.11.025

Annals of Vascular Surgery

Volume 33, May 2016, Pages 149-158

https://doi.org/10.1016/j.avsg.2015.11.025 Get rights and content

Background

Costs related to diabetic foot ulcer (DFU) care are greater than $1 billion annually and rising. We sought to describe the impact of diabetes mellitus (DM) on foot ulcer admissions in the United States, and to investigate potential explanations for rising hospital costs.

Methods

The Nationwide Inpatient Sample (2005–2010) was queried using International Classification of Diseases, 9th Revision (ICD-9) codes for a primary diagnosis of foot ulceration. Multivariable analyses were used to compare outcomes and per-admission costs among patients with foot ulceration and DM versus non-DM.

Results

In total, 962,496 foot ulcer patients were admitted over the study period. The overall rate of admissions was relatively stable over time, but the ratio of DM versus non-DM admissions increased significantly (2005: 10.2 vs. 2010: 12.7; P < 0.001). Neuropathy and infection accounted for 90% of DFU admissions, while peripheral vascular disease accounted for most non-DM admissions. Admissions related to infection rose significantly among DM patients (2005: 39,682 vs. 2010: 51,660; P < 0.001), but remained stable among non-DM patients. Overall, DM accounted for 83% and 96% of all major and minor amputations related to foot ulcers, respectively, and significantly increased cost of care (DM: $1.38 vs. non-DM: $0.13 billion/year; P < 0.001). Hospital costs per DFU admission were significantly higher for patients with infection compared with all other causes ($11,290 vs. $8,145; P < 0.001).

Conclusions

Diabetes increases the incidence of foot ulcer admissions by 11-fold, accounting for more than 80% of all amputations and increasing hospital costs more than 10-fold over the 5 years. The majority of these costs are related to the treatment of infected foot ulcers. Education initiatives and early prevention strategies through outpatient multidisciplinary care targeted at high-risk populations are essential to preventing further increases in what is already a substantial economic burden.

Introduction

The prevalence of diabetes mellitus is increasing annually across the United States. The number of hospital discharges associated with diabetes has increased from 4.6 million in 2001 to 5.5 million in 2009.¹ As a result, costs associated with diabetes care are also rising. In 2012, the direct medical costs associated with diabetes were $176 billion, which is 2.3 times higher than healthcare costs associated with care of nondiabetic patients.²

Approximately 33% of diabetes-related costs have been linked to the treatment of foot ulcers,³ the majority of which are related to inpatient hospital admissions.⁴ Hospital inpatient care accounts for at least 50% of the national diabetes cost burden overall,⁵ and hospital charges and costs related to diabetic foot ulcers specifically have increased significantly over the past 5 years.⁶ Interestingly, hospital admissions for diabetic foot ulcers were relatively stable between 2003 and 2007, ranging from 112,000 to 115,000 admissions per year.⁷ In addition, the rate of lower extremity amputation among patients with diabetes is stable or even decreasing; the estimated lower extremity amputation rate among diabetic patients was 3.1/10,000 admissions in 2001 compared with 2.2/10,000 admissions in 2009.⁸ Therefore it is currently unclear why hospital costs associated with diabetic foot ulcer care is increasing.

In this study, we sought to describe the impact of diabetes on foot ulcer admissions in the United States, including the etiology, incidence of major and minor lower extremity amputations, and to investigate potential explanations for rising hospital costs among patients with foot ulcers and diabetes compared with those with foot ulcers and no diabetes.

Section snippets

Study Design

Data were obtained from the Healthcare Cost and Utilization Project's (HCUP) Nationwide Inpatient Sample (NIS). We performed a retrospective analysis of all patients aged 18 to 99 years, admitted with a primary diagnosis of foot ulceration (ICD-9 codes 440.23, 707.14–707.15) between January 1, 2005 and December 31, 2010. Patients admitted for trauma, acute limb ischemia, compartment syndrome, fasciotomy, pressure ulcers, venous hypertension, or gestational diabetes, as well as those with

Temporal Trends in Foot Ulcer Admissions Over Time

There were 962,496 foot ulcer admissions over the 6-year study period. Of these, 91.8% (n = 883,463) of admissions were among patients with diabetes, compared with 8.2% (n = 79,033) admissions among patients with no diabetes. The number of foot ulcer admissions in 2005 was 150,418 (95% confidence interval [CI] 148,755–152,082). The number of foot ulcer admissions increased to 165,277 (95% CI 163,537–167,016) in 2006 (P < 0.001), after which there were no significant variations in the number of

Discussion

The prevalence of diabetes and diabetes-related morbidity is rising. Based on data from the Centers for Disease Control (CDC), the US population in 2010 was 308,745,538.¹¹ Assuming a diabetes prevalence of 8.3%,¹² approximately 25,625,880 Americans are currently affected by diabetes. Similarly, hospital costs are rising.6, 13, 14 Specifically, diabetic foot ulcer care costs the Medicare system approximately $1.5 billion per year,⁴ ranging anywhere from $3,000 to $108,000 per ulcer depending on

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This was a retrospective single-center cohort study of unplanned vascular surgery admissions from August 1, 2019 to January 22, 2020. Data on patient demographics, markers of quality of palliative care, mortality, and cause of death of unplanned admission to the vascular surgery department were collected from hospital and general practitioner records and evaluated against EoLC to evaluate predictors and efficacy of EoLC. Quality of palliative care markers included documentation of preferred place of death and care priorities, time spent in hospital and the intensive care unit toward the end of life, and realization of documented care objectives. EoLC input was defined as a dedicated palliative care consultation (PCC) by a palliative care professional, medical doctor, surgeon, or advanced care practitioner. We also conducted a subgroup analysis of patients within this group with chronic limb-threatening ischemia (CLTI), diabetic foot, and ruptured aortic aneurysms, as all patients in this group should be offered EoLC according to international guidelines.
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Diabetic foot ulcers (DFUs) are a devastating complication for diabetic patients that have debilitating effects and can ultimately lead to limb amputation. Healthy wounds progress through the phases of healing leading to tissue regeneration and restoration of the barrier function of the skin. In contrast, in diabetic patients dysregulation of these phases leads to chronic, non-healing wounds. In particular, unresolved inflammation in the DFU microenvironment has been identified as a key facet of chronic wounds in hyperglyceamic patients, as DFUs fail to progress beyond the inflammatory phase and towards resolution. Thus, control over and modulation of the inflammatory response is a promising therapeutic avenue for DFU treatment. This review discusses the current state-of-the art regarding control of the inflammatory response in the DFU microenvironment, with a specific focus on the development of biomaterials-based delivery strategies and their cargos to direct tissue regeneration in the DFU microenvironment.
Assessing the Utility of Toe Arm Index and Toe Pressure in Predicting Wound Healing in Patients Undergoing Vascular Intervention
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Objective measures of perfusion such as an ankle-brachial index (ABI) and toe pressure remain important in prognosticating wound healing. However, the use of ABI is limited in patients with incompressible vessels and toe pressure may not be comparable across patients. While a toe arm index (TAI) may be of value in this setting, its role as clinical indicator of perfusion for healing in patients with lower-extremity wounds has not been well established.
A retrospective review was performed of all vascular patients with lower-extremity wounds that underwent peripheral vascular intervention between 2014-2019. Data regarding patient demographics, comorbidities, TAI, ABI, toe pressures, and the wound, ischemia, and foot infection (WIfI) score were collected. Associations between patient variables and wound healing at various time points were evaluated.
A total of 173 patients (67.7 ± 10.9 years; 71.1% male) were identified with lower-extremity wounds. Most patients underwent endovascular intervention (77.5%). Patients were followed for a median of 416 (IQR 129–900) days. Mean postoperative TAI was 0.35 ± 0.19 and mean WIfI score was 2.60 ± 1.17. Nine percent (15) of patients healed within 1 month, 44.8% (69) healed within 6 months, and 65.5% (97) healed within 1 year of revascularization without need for major amputation. Those that healed within 1 year without any major amputation did not differ from those that did not heal based on age, gender, race, comorbidities, periprocedural medications, or procedures performed. However, patients that healed without major amputation had a higher postoperative TAI (0.38 vs. 0.30, P = 0.02), higher toe pressure (53 vs. 40 mm Hg, P = 0.004), and lower WIfI score (2.26 vs. 3.12, P < 0.001). Patients that healed with 1 year without requiring any amputation had similar associations with postoperative TAI, toe pressure, and WIfI. Additionally, they were more likely to be White (P = 0.019) and have an open surgical procedure (P < 0.001) and less likely to have chronic kidney disease (P = 0.001) or diabetes (P = 0.008). A Youden index was calculated and identified a TAI value of 0.30 that optimized sensitivity and specificity for wound healing. The area under the curve for TAI as a predictor of wound healing was 0.62.
Higher postoperative TAI is associated with higher odds of wound healing without need for major amputation. Toe arm index is therefore a useful tool to identify patients with adequate arterial perfusion to heal lower-extremity wounds. However, the area under the curve is poor for TAI when used as a sole predictor of wound healing potential suggesting that TAI should be one of multiple factors to considered when prognosticating wound healing potential.
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Diabetes related foot disease (DFD) is a common reason for admission to hospital, but the predictive factors for repeat admission are poorly defined. The primary aim of this study was to identify rates and predictive factors for DFD related hospital re-admission.
Patients admitted to hospital for treatment of DFD at a single regional centre were recruited prospectively between January 2020 and December 2020. Participants were followed for 12 months to evaluate the primary outcome of hospital re-admission. The relationship between predictive factors and re-admission were examined using non-parametric statistical tests and Cox proportional hazard analyses.
The median age of the 190 participants was 64.9 (standard deviation 13.3) years and 68.4% were male. Forty-one participants (21.6%) identified themselves as Aboriginal or Torres Strait Islander people. One hundred participants (52.6%) were re-admitted to hospital at least once over 12 months. The commonest reason for re-admission was for treatment of foot infection (84.0% of first re-admission). Absent pedal pulses (unadjusted hazard ratio [HR] 1.90; 95% confidence interval [CI] 1.26 – 2.85), loss of protective sensation (LOPS) (unadjusted HR 1.98; 95% CI 1.08 – 3.62), and male sex (unadjusted HR 1.62; 95% CI 1.03 – 2.54) increased the risk of re-admission. After risk adjustment, only absence of pedal pulses (HR 1.92, 95% CI 1.27 – 2.91) and LOPS (HR 2.02, 95% CI 1.09 – 3.74) significantly increased the risk of re-admission.
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View all citing articles on Scopus

: Disclosures: No competing interests declared. This work was completed without financial support.

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Clinical ResearchBurden of Infected Diabetic Foot Ulcers on Hospital Admissions and Costs

Background

Methods

Results

Conclusions

Introduction

Section snippets

Study Design

Temporal Trends in Foot Ulcer Admissions Over Time

Discussion

J Vasc Surg

Ann Vasc Surg

Semin Vasc Surg

Number (in Thousands) of Hospital Discharges with Diabetes as Any-Listed Diagnosis, United States, 1988–2009

National Diabetes Statistic Report, 2014

A cost analysis of diabetic lower-extremity ulcers

Diabetes Care

Economic costs of diabetes in the U.S. In 2007

Diabetes Care

Trends and determinants of costs associated with the inpatient care of diabetic foot ulcers

J Vasc Surg

Number (in Thousands) of Hospital Discharges with Peripheral Arterial Disease (PAD), Ulcer/Inflammation/Infection (ULCER), or Neuropathy as First-Listed Diagnosis and Diabetes as Any-Listed Diagnosis United States, 1988–2007

Number (in Thousands) of Hospital Discharges for Nontraumatic Lower Extremity Amputation with Diabetes as a Listed Diagnosis, United States, 1988–2009

ICDPIC: Stata Module to Provide Methods for Translating International Classification of Diseases (Ninth Revision) Diagnosis Codes into Standard Injury Categories and/or Scores

Consumer Price Index (CPI) Conversion Factors 1774 to Estimated 2022 to Convert to Dollars of 2010

NVSS—National Vital Statistics System

Clinical Research
Burden of Infected Diabetic Foot Ulcers on Hospital Admissions and Costs