ORIGINAL ARTICLES
Evaluation of Wound Care and Health-Care Use Costs in Patients with Diabetic Foot Ulcers Treated with Negative Pressure Wound Therapy versus Advanced Moist Wound Therapy Vickie R. Driver, DPM, MS* Peter A. Blume, DPM† Background: We conducted a post-hoc retrospective analysis of patients enrolled in a randomized controlled trial to evaluate overall costs of negative pressure wound therapy (NPWT; V.A.C. Therapy; KCI USA, Inc, San Antonio, Texas) versus advanced moist wound therapy (AMWT) in treating grade 2 and 3 diabetic foot wounds during a 12-week therapy course. Methods: Data from two study arms (NPWT [n ¼ 169] or AMWT [n ¼ 166]) originating from Protocol VAC2001-08 were collected from patient records and used as the basis of the calculations performed in our cost analysis. Results: A total of 324 patient records (NPWT ¼ 162; AMWT ¼ 162) were analyzed. There was a median wound area reduction of 85.0% from baseline in patients treated with NPWT compared to a 61.8% reduction in those treated with AMWT. The total cost for all patients, regardless of closure, was $1,941,472.07 in the NPWT group compared to $2,196,315.86 in the AMWT group. In patients who achieved complete wound closure, the mean cost per patient in the NPWT group was $10,172 compared to $9,505 in the AMWT group; the median cost per 1 cm 2 of closure was $1,227 with NPWT and $1,695 with AMWT. In patients who did not achieve complete wound closure, the mean total wound care cost per patient in the NPWT group was $13,262, compared to $15,069 in the AMWT group. The median cost to close 1 cm 2 in wounds that didn’t heal using NPWT was $1,633, compared to $2,927 with AMWT. Conclusions: Our results show greater cost effectiveness with NPWT versus AMWT in recalcitrant wounds that didn’t close during a 12-week period, due to lower expenditures on procedures and use of health-care resources. (J Am Podiatr Med Assoc 104(2): 147153, 2014)
The rising global burden of diabetes and its complications have resulted in a massive drain on economic resources for society and individuals. In the United States alone, at least 23.6 million people are living with diabetes, 17.9 million of whom are diagnosed and 5.7 million not yet diagnosed.1 In 2010, the world prevalence of diabetes was approximately 6.4%, affecting 285 million adults; this number is expected to rise to 439 million adults by 2030.2 *Department of Surgery, Veterans Affairs New England Health Care Division, Providence, RI. †Department of Anesthesiology, Yale School of Medicine, New Haven, CT. Corresponding author: Vickie R. Driver, DPM, MS, FACFAS, Department of Surgery, VA New England Health Care Division, Department of Surgery, 830 Chalkstone Ave, Providence, RI 02908. (E-mail: [email protected])
The rise of diabetes will likely prompt a proportional increase in diabetic foot ulcers (DFUs), one of the most common complications of diabetes. In the United States, the annual incidence of DFUs is 1% to 4%, with a prevalence of about 4% to 10%, and a lifetime risk of occurrence between 15% and 25%.3-5 The total cost of treatment products, amputation, rehabilitation, and long-term care amounted to a staggering US $10.9 billion in 2006.4 The estimated average cost of treating a DFU in the United States ranges widely—from $4,595 per ulcer episode to nearly $28,000 (1995 US dollars) during the 2 years after diagnosis, and in excess of $30,000 during the ulcer’s life cycle.5-7 Approximately 85% of amputations are preceded by foot ulcers,8 with direct costs of performing a single amputation approaching $34,000.9 It is clear from ballooning
Journal of the American Podiatric Medical Association Vol 104 No 2 March/April 2014
147
health-care costs that treatment decisions must be considered on the basis of overall wound-care costs. The standard treatment for DFUs includes patient and wound assessment, moist wound care, frequent debridement, infection control, adequate off-loading, and restoring circulation.10-12 Based on suggested guidelines for the treatment of diabetic ulcers of the lower extremity, patients who fail to show a 40% reduction in ulcer size after 4 weeks of a given therapy should be reevaluated and other therapies should be considered.13 Historically, negative pressure wound therapy (NPWT) has largely been employed as a salvage therapy in diabetic wound treatment after other therapies have failed to close the ulcer. However, a growing body of evidence suggests that advanced technologies, such as NPWT, may be more efficacious when initiated early in the course of wound treatment. Reported benefits of earlier NPWT initiation include a reduction in the overall length of home-care stay for patients with surgical wounds or pressure ulcers,14 decreased mean time to 50% closure and reduced length of stay in long-term acute care wounds,8,15 reduction in total and variable costs for traumatic patients,16 and reduced total wound treatment costs.8 The American Recovery and Reinvestment Act emphasizes the importance of comparative effectiveness under the National Institutes of Health Challenge Grants in Health and Science Research. According to a 2007 Congressional Budget Office white paper, the term comparative effectiveness is defined as ‘‘generating evidence that compares treatments,’’ and includes comparative economics as well.17 Few comparative studies, however, have examined the direct costs as well as costs of therapeutic failure of advanced wound care modalities initiated early in the treatment of diabetic wounds. Whereas evidence-based medicine guidelines include well-defined scientific methods of conducting clinical efficacy studies, there is less agreement on how to conduct cost-effectiveness economic analyses. The standard methodology in a clinical trial typically calls for a finite period of time during which incidence of closure is measured. However, overall resource use should be an important consideration in determining true cost-effectiveness of a therapy. The objective of our study was to comparatively evaluate health-care costs, regardless of closure status, during a 12-week course of therapy. We conducted a post-hoc retrospective analysis of patients enrolled in a randomized controlled trial (RCT) to evaluate overall economic
148
costs of NPWT as delivered by vacuum assisted closure therapy (V.A.C. therapy, KCI USA, Inc, San Antonio, Texas) versus advanced moist wound therapy (AMWT) in treating Wagner’s grade stage 2 and 3 diabetic foot wounds.
Research Design and Methods We performed a post-hoc analysis of data obtained from diabetic foot ulcer patients who participated in an RCT to evaluate clinical efficacy of NPWT compared with AMWT. In the original study, a total of 342 patients were enrolled in a multicenter trial until ulcer closure or a maximum of 112 days.18 The patient population consisted of diabetic adults 18 years old or older who had a grade 2 or 3 calcaneal, dorsal, or plantar foot ulcer greater than 2 cm2 in area after debridement. Negative pressure wound therapy was delivered using the V.A.C. Therapy System. Advanced moist wound therapy dressings included use of alginates, hydrocolloids, foams, or hydrogels, according to Wound, Ostomy and Continence Nursing Society guidelines and institutional treatment protocols that follow standards of care for treating DFUs.19 Skin substitutes, cytokines, recombinant human platelet-derived growth factor, and similar therapies were prohibited in both treatment arms. Negative pressure wound therapy dressing changes were performed every 48 to 72 hours (minimum 3 times per week). Complete ulcer closure was defined as skin closure (100% epithelialization) without drainage or dressing requirements, either by delayed primary closure or healing by secondary intention. Patients were examined weekly for the first 4 weeks (day 28) and then every other week until day 112 or ulcer closure by any means. Economic Analysis Data from two different study arms (NPWT [n ¼ 169] or AMWT [n ¼ 166]) originating from Protocol VAC2001-08 were collected from patient records and used as the basis of the calculations performed in our cost analysis. Patients with missing data for hospitalizations during which a split- or full-thickness graft or flap was performed were excluded from analysis (n ¼ 7 for NPWT; n ¼ 4 for AMWT). Therefore, a total of 162 NPWT-treated and 162 AMWT-treated wounds were included in the final analysis. Costs were divided into wound therapy costs and nontherapy wound treatment costs. Wound therapy costs consisted of the cost of dressings or the
March/April 2014 Vol 104 No 2 Journal of the American Podiatric Medical Association
NPWT system, and labor during dressing changes. Nonwound therapy costs encompassed concomitant antibiotic therapy, acute inpatient services (including acute-care hospitalizations and woundrelated surgical procedures that were performed in an acute-care facility), extended care hospitalizations (ie, stays in skilled nursing facilities (SNFs), rehabilitation clinics, or hospice), and outpatient surgical procedures. Costs were calculated retrospectively based on the observed frequency that trial participants used health-care resources. Estimated hospital costs were derived from data from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample.20 Mean cost of physician services for lowerlimb amputation, debridement, and other woundrelated surgical procedures in acute-care and outpatient facilities were estimated using the Medicare Resource-Based Relative Value Scale 2007.21 The mean cost per inpatient day in extended-care facilities was estimated using the Medicare reimbursement rate for an SNF.22 Statistical Analysis For wound closure rate and rate of secondary amputation, treatment comparison was performed using Fisher’s exact test. For time to wound closure, a log-rank test was used for treatment comparison. For continuous parameters, such as total cost per patient, data were summarized using descriptive statistics (mean, standard deviation, median, and 95% two-sided confidence limits) by treatment group. All statistical tests were two-sided.
Results The final economic analysis was based on 162 NPWT-treated and 162 AMWT-treated wounds. Table 1 describes the patient demographics for both of these populations. Total Health-Care Resource Costs for All Patients The total cost for all patients, regardless of closure, was $1,941,472.07 (average per-patient cost: $11,984.40) in the NPWT group compared to $2,196,315.86 (average per-patient cost: $13,557.51) in the AMWT group (Table 2). The total wound treatment cost was $764,392.30 (average per-patient cost: $4,718.47) in the NPWT group compared to $374,599.14 (average per-patient cost: $2,312.34) in the AMWT group. The total nontherapy wound
Table 1. Patient Demographics Characteristics
NPWT (n ¼ 162)
AMWT (n ¼ 162)
Age (mean 6 SD) (years)
58 6 12
59 6 12
Sex (Male/Female)
136/26
120/42
Weight (mean 6 SD) (kg)
98.9 6 24.5
93.9 6 25.9
Current smoker (No.[%])
33 (20.4%)
32 (19.8%)
Type I diabetes (No.[%])
15 (9.3%)
14 (8.6%)
Type II diabetes (No.[%])
147 (90.7%)
148 (91.4%)
64 (39.5%)
68 (42.0%)
Wound stage (Wagner’s scale) Grade 2 (No.[%]) Grade 3 (No.[%]) Mean wound depth (cm)
75 (46.3%)
70 (43.2%)
1.0
1.0
Abbreviations: AMWT, advanced moist wound therapy; NPWT, negative pressure wound therapy.
treatment cost was $1,177,079.77 (average perpatient cost: $7,265.93) in the NPWT group compared to $1,821,716.73 (average per-patient cost: $11,245.17) in the AMWT group. Health-Care Resource Costs for Patients Who Achieved Wound Closure The removal of records with missing data resulted in a sample of 67 NPWT patients (41%) who achieved complete wound closure in the 112-day study compared to 44 AMWT patients (27%). The total aggregate wound care cost for NPWT patients was $681,549.42 (average per-patient cost: $10,172.38) compared to $418,230.24 (average perpatient cost: $9,505.23) for AMWT patients (Table 2). For NPWT patients, approximately 42% ($285,032.63) of the total health-care dollars were spent directly on NPWT while approximately 58% ($396,516.79) (Table 3) were spent on nontherapy wound treatment items. For AMWT patients, approximately 16% ($66,573.47) of the total healthcare dollars were spent on AMWT while approximately 84% ($351,656.77) (Table 3) were spent directly on nontherapy wound treatment items. The average nonwound treatment cost per NPWT patient was $10,716.67 compared to $13,525.26 per AMWT patient (Table 3). Health-Care Resource Costs for Patients Who Failed to Achieve Wound Closure Complete patient records were analyzed for 95 NPWT patients (59%) who failed to achieve complete wound closure during the 112-day study compared to 118 AMWT patients (73%). The total
Journal of the American Podiatric Medical Association Vol 104 No 2 March/April 2014
149
Table 2. Per-Patient Cost Based on Wound Closure Status Total Average Costs
Average Cost Per Patient
SD
Lower Confidence Limit
Upper Confidence Limit
NPWT (n ¼ 162)
$1,941,472.07
$11,984.40
$19,423.76
$8,970.69
$14,998.10
AMWT (n ¼ 162)
$2,196,315.86
$13,557.51
$21,923.21
$10,156.00
$16,959.01
All Patients
Patients Who Achieved Wound Closure NPWT (n ¼ 67)
$681,549.42
$10,172.38
$13,692.47
$6,832.52
$13,512.23
AMWT (n ¼ 44)
$418,230.24
$9,505.23
$20,289.99
$3,336.51
$15,673.95
Patients Who Did Not Achieve Wound Closure NPWT (n ¼ 95)
$1,259,922.65
$13,262.34
$22,595.76
$8,659.35
$17,865.34
AMWT (n ¼ 118)
$1,778,085.62
$15,068.52
$22,396.32
$10,985.34
$19,151.71
Abbreviations: AMWT, advanced moist wound therapy; NPWT, negative pressure wound therapy.
aggregate wound-care cost for these NPWT patients was $1,259,922.65 (average cost per patient: $13,262.34) compared to $1,778,085.62 (average cost per patient: $15,068.52) for these AMWT patients (Table 2). For NPWT patients, approximately 38% ($479,359.67) of the total health-care dollars were spent directly on NPWT while approximately 62% ($780,562.98) (Table 3) were spent on nontherapy wound treatment items (Table 4). For AMWT patients, approximately 17% ($308,025.67) of the total health-care dollars were spent directly on AMWT while approximately 83% ($1,470,059.95) (Table 3) were spent on nontherapy wound treatment items (Table 4). The average nonwound treatment cost per NPWT patient was $13,694.09 compared to $17,927.56 per AMWT patient (Table 3). Median Cost per cm2 Reduction There was a median wound area reduction of 85.0% from baseline in NPWT patients compared to a 61.8% reduction in AMWT patients. For those patients who achieved complete wound closure in the 112-day study, the median cost to close 1 cm2 of
the wound using NPWT was $1,226.54 compared to $1,695.45 using AMWT. For those patients who failed to achieve complete closure during the 112day active treatment phase, the median cost to close 1 cm2 of the wound using NPWT was $1,633.47 compared to $2,926.51 using AMWT. Regardless of closure status, the overall median cost to close 1 cm2 of the wound using NPWT was $1,460.42 compared to $2,566.17 using AMWT.
Discussion This study evaluated overall economic costs of NPWT versus AMWT for the treatment of grade 2 and 3 DFUs. More DFUs were closed completely with NPWT compared to AMWT with a higher average cost per patient in the NPWT group. However, more health-care dollars were spent on nontherapy wound treatment costs for AMWT patients. For those patients who failed to achieve complete closure, the total average wound-care cost was lower in the NPWT group compared to the AMWT group. Additionally, overall total costs for closed and nonclosed patients were also lower for the NPWT group.
Table 3. Nontherapy Wound Treatment Costs Average Cost per Patient for Non-Therapy Wound Treatment Cost
Total Non-Therapy Wound Treatment Cost
Percentage of Health-Care Dollars Spent Directly on Non-Therapy Wound Treatment Cost
Patients Who Achieved Wound Closure NPWT (n ¼ 67)
$10,716.67
$396,516.79
;58%
AMWT (n ¼ 44)
$13,525.26
$351,656.77
;84%
Patients Who Did Not Achieve Wound Closure NPWT (n ¼ 95)
$13,694.09
$780,562.98
;62%
AMWT (n ¼ 118)
$17,927.56
$1,470,059.95
;83%
Abbreviations: AMWT, advanced moist wound therapy; NPWT, negative pressure wound therapy.
150
March/April 2014 Vol 104 No 2 Journal of the American Podiatric Medical Association
Table 4. Health-Care Resource Cost for Nontherapy Wound Treatment for Patients Who Did Not Achieve Wound Closure
Health-Care Resource
Total Cost for NPWT Patients Who Did Not Achieve Wound Closure
Concomitant Antibiotic Therapy
$31,404.76
Total Cost for AMWT Patients Who Did Not Achieve Wound Closure $26,227.68
ACH – Amputation
$126,060.00
$441,210.00
ACH – Management of infection (without amputation)
$190,076.00
$360,144.00
ACH – All other reasons
$236,880.00
$485,604.00
ECH – SNF ECH – REHAB IF – Amputation IF – Debridements
$37,319.42
$47,177.38
$110,735.10
$15,038.10
$2,399.68
$7,798.96
$936.90
$2,342.25
IF – Other surgeries
$2,611.56
$1,119.24
IF – Bed-side visits
$17,926.00
$37,823.86
OF – Debridements
$23,301.96
$42,383.88
$911.60
$3,190.60
$780,562.98
$1,470,059.95
OF – Other surgeries Total
ACH: acute-care hospitalization; ECH: extended-care hospitalization; IF: inpatient facility; OF: outpatient facility.
Previous studies have included economic analyses based on the costs of treating wounds using NPWT compared to traditional wound-care dressings. For example, using clinical outcomes reported by Armstrong et al23 in their published RCT comparing NPWT and moist wound therapy (ie, alginates, hydrocolloids, foams, or hydrogels) for treating diabetic foot wounds, Apelqvist et al24 demonstrated cost savings using NPWT, including a reduction in average direct cost per patient and average total cost to achieve healing. Flack and colleagues25 used a Markov model to approximate the cost per amputation avoided and the cost per quality-adjusted life year of NPWT compared to traditional and advanced dressings. Results from this model showed an overall lower cost of care for NPWT patients compared to traditional therapies ($52,830 vs. $61,757 per person, respectively).25 Our findings are consistent with prior studies, showing higher overall total costs (wound and non–wound treatment related) for the AMWT group as compared to the NPWT group. Interestingly in our study, the average cost per patient for nontherapy wound treatment was higher in the AMWT group, regardless of closure, compared to the NPWT group. Overall, in the AMWT group, more health-care dollars were spent on nontherapy wound treatment (eg, antibiotics, hospitalizations, surgical procedures, and extendedcare hospitalization) costs than on actual wound treatment (ie, dressings and labor for dressing changes), which could indicate higher rates of complications and greater acute-care hospitaliza-
tions associated with this group (Table 4). A report by Rogers et al26 estimated that a major limb amputation costs approximately $70,434 (adjusting for health-care inflation in 2007) and that annual costs for diabetic amputations are about $11.7 billion. Indeed, in our study, there were more major and minor amputations in the AMWT group as compared to the NPWT group, which contributed greatly to nontherapy AMWT costs. Thus, this economic analysis shows that not only did AMWT patients heal slower, but the overall costs, including nontherapy costs, were greater in the AMWT group as compared to the NPWT group. The median cost to close 1 cm2 of a wound was lower for NPWT patients compared to AMWT patients, regardless of closure status, suggesting that NPWT may be more cost effective in terms of wound progression toward closure. Also, this costper-cm2 reduction over time may be of particular consideration to payers in cases where NPWT is used as a bridge to closure. The speed at which wounds undergo epithelialization is important with respect to cost and transition to surgical reconstruction with flaps and grafts. Our results are similar to a study by de Leon et al 27 who retrospectively examined the average daily wound volume reduction for postsurgical patients treated with NPWT compared to those treated with topical advanced moist healing therapies (control). The results showed that NPWT patients had a significantly higher average daily rate of volume reduction compared to the control group (5.02 6 13.36 versus 0.40 6 0.88 cm 3 /day; P ¼ 0.046), and more
Journal of the American Podiatric Medical Association Vol 104 No 2 March/April 2014
151
importantly, the cost-per-cm3 reduction was $11.90/ cm3 for NPWT patients versus $30.92/cm3 for the control group. Because the patients in the Blume RCT18 were high-risk patients with multiple comorbidities, achieving wound closure in a timely manner was critical to prevent further complications. Although there was a higher average cost per patient using NPWT for patients achieving closure, there were more DFUs that achieved closure and a significant reduction in median time to closure with NPWT. This type of high-risk patient may also benefit from early intervention with NPWT, which may affect treatment costs. Previous studies have demonstrated that early initiation of NPWT can reduce length of stay across care settings (acute care,16 long-term acute care,8,15 and home care14), which may translate into a potential reduction in costs. Furthermore, compared to late NPWT initiation, early NPWT initiation has also been associated with a reduction in overall wound treatment cost for diabetic patients in a long-term acute-care facility8 and for trauma patients in an acute care facility.16 Further studies are necessary to determine the impact of early intervention with NPWT on clinical outcomes and wound care costs for the treatment of DFUs. Although the primary endpoint for the Blume RCT18 and most clinical wound trials is complete wound closure, less than 50% of patients in that study18 achieved full closure. It is well reported that patients whose wounds do not close contribute to the majority of cost. Indeed, that is the case in our economic analysis. Because wound healing is a dynamic approach, especially in cases of nonhealing recalcitrant wounds, analysis based on various trajectories, versus all-or-none criteria, may be a more pragmatic approach to determining cost effectiveness.28 Thus, wound volume reduction, percent granulation, and wound contraction may be important trajectories that can be transitioned with respect to cost per cm2. The RCT data reported by Blume et al18 allowed us to evaluate cost effectiveness based on numerous trajectories. A weakness of the study was the lack of comprehensive data collection of multiple endpoints, which may have shown greater costs with respect to either group. A sensitivity analysis to examine the effects of unaccounted costs and varied assumptions with respect to our cost estimates was not performed. Newer techniques, such as the Arranz device,29 could have been used to include greater inclusion of depth and volume measurements in data gathering. In addition, wound
152
tracings may not be as accurate as computerassisted recordings of wound parameters, and debridements and interventions could have been tracked in a more succinct manner. In summary, our results show that NPWT is more cost effective than AMWT in recalcitrant wounds because of lower expenditures on resource use and procedures. Acknowledgment: The authors thank Jason Chan, of KCI, USA, and Bruce Stouch, of BCS Consulting, for performing the data analyses, and Karen Beach, Ricardo Martinez, and Julissa V. Ramos, KCI, for providing medical writing support. Financial Disclosure: None reported. Conflict of Interest: None reported.
References 1. CENTERS FOR DISEASE CONTROL AND PREVENTION: National Diabetes Fact Sheet, 2007. 1-1-2008. Atlanta, GA, U.S. Department of Health and Human Services, Centers for Disease Control and Prevention. 6-1-2009. 2. SHAW JE, SICREE RA, ZIMMET PZ: Global estimates of the prevalence of diabetes for 2010 and 2030. Diabetes Res Clin Pract 87: 4, 2010. 3. SINGH N, ARMSTRONG DG, LIPSKY BA: Preventing foot ulcers in patients with diabetes. JAMA 293: 217, 2005. 4. BOULTON A, BOWLING F: ‘‘Diabetic Foot Ulcers,’’ in Controversies in Treating Diabetes, edited by AI Vinik, D LeRoith, p 229, Humana Press, New York, NY, 2008. 5. SNYDER RJ, HANFT JR: Diabetic foot ulcers — effects on quality of life, costs, and mortality and the role of standard wound care and advanced-care therapies in healing: a review. Ostomy Wound Manage 55: 28, 2009. 6. RAMSEY SD, NEWTON K, BLOUGH D, ET AL: Incidence, outcomes, and cost of foot ulcers in patients with diabetes. Diabetes Care 22: 382, 1999. 7. HOLZER SE, CAMEROTA A, MARTENS L, ET AL: Costs and duration of care for lower extremity ulcers in patients with diabetes. Clin Ther 20: 169, 1998. 8. DRIVER VR, DE LEON JM: Health economic implications for wound care and limb preservation. J Manag Care Med 11: 13, 2008. 9. RAGNARSON TENNVALL G, APELQVIST J: Health-economic consequences of diabetic foot lesions. Clin Infect Dis 39: S132, 2004. 10. PHAM HT: Wound care in diabetic foot ulceration. Wounds 12: 82B, 2000. 11. SIBBALD RG, TORRANCE G, HUX M, ET AL: Cost-effectiveness of becaplermin for nonhealing neuropathic diabetic foot ulcers. Ostomy Wound Manage 49: 76, 2003. 12. CAVANAGH PR, LIPSKY BA, BRADBURY AW, ET AL: Treatment for diabetic foot ulcers. Lancet 366: 1725, 2005. 13. STEED DL, ATTINGER C, COLAIZZI T, ET AL: Guidelines for the treatment of diabetic ulcers. Wound Repair Regen 14: 680, 2006.
March/April 2014 Vol 104 No 2 Journal of the American Podiatric Medical Association
14. BAHARESTANI MM, HOULISTON-OTTO DB, BARNES S: Early versus late initiation of negative pressure wound therapy: examining the impact on home care length of stay. Ostomy Wound Manage 54: 48, 2008. 15. DE LEON JM, NAGEL M, FUDGE M, ET AL: Early use of negative pressure wound therapy in long-term acute care patients is associated with reduced length of stay. Abstract presented at the Third Congress of the World Union of Wound Healing Societies, June 4–8, 2008, Toronto, Ontario. PF225, 2008. 16. KAPLAN M, DALY D, STEMKOWSKI S: Early intervention of negative pressure wound therapy utilizing vacuum assisted closure in trauma patients: impact on hospital length of stay and cost. Adv Skin Wound Care 22: 128, 2009. 17. CONGRESSIONAL BUDGET OFFICE: Research on the comparative effectiveness of medical treatments. 1–48. 12-12007. Washington, DC, Congress of the United States, Congressional Budget Office. 18. BLUME PA, WALTERS J, PAYNE W, ET AL: Comparison of negative pressure wound therapy using vacuum-assisted closure with advanced moist wound therapy in the treatment of diabetic foot ulcers: a multicenter randomized controlled trial. Diabetes Care 31: 631, 2008. 19. [No author listed]. Guideline for management of wounds in patients with lower-extremity arterial disease. 6-12002. Glenview, IL, Wound Ostomy and Continence Nurses Society. WOCN clinical practice guideline series; no. 1. 20. RUSSO CA, STEINER C, SPECTOR W: Hospitalizations related to pressure ulcers among adults 18 years and older, 2006. HCUP Statistical Brief #64, 1–9. 12-1-2008, Agency for Healthcare Research and Quality, Rockville, MD, 127-2010. 21. WEST VIRGINIA BUREAU FOR MEDICAL SERVICES: 2007 National
22.
23.
24.
25.
26.
27.
28.
29.
Physician Fee Schedule Relative Value File. 1–52. 1-12007. West Virginia, West Virginia Department of Health and Human Services (DHHR). 10-18-2011. CENTERS FOR MEDICARE AND MEDICAID SERVICES (CMS) H: Medicare Program: Prospective payment system and consolidated billing for skilled nursing facilities — Update — Notice. Fed Regist 71: 43158, 2006. ARMSTRONG DG, LAVERY LA, Diabetic Foot Study Consortium: Negative pressure wound therapy after partial diabetic foot amputation: a multicentre, randomised controlled trial. Lancet 366: 1704, 2005. APELQVIST J, ARMSTRONG DG, LAVERY LA, ET AL: Resource utilization and economic costs of care based on a randomized trial of vacuum-assisted closure therapy in the treatment of diabetic foot wounds. Am J Surg 195: 782, 2008. FLACK S, APELQVIST J, KEITH M, ET AL: An economic evaluation of VAC therapy compared with wound dressings in the treatment of diabetic foot ulcers. J Wound Care 17: 71, 2008. ROGERS LC, LAVERY LA, ARMSTRONG DG: The right to bear legs–an amendment to healthcare: how preventing amputations can save billions for the US Health-care System. JAPMA 98: 166, 2008. DE LEON JM, BARNES S, NAGEL M, ET AL: Cost-effectiveness of negative pressure wound therapy for postsurgical patients in long-term acute care. Adv Skin Wound Care 22: 122, 2009. LAVERY LA, BARNES SA, KEITH MS, ET AL: Prediction of healing for post-operative diabetic foot wounds based on early wound area progression. Diabetes Care 31: 26, 2008. KIESER DC, HAMMOND C: Leading wound care technology: The ARANZ medical silhouette. Adv Skin Wound Care 24: 68, 2011.
Journal of the American Podiatric Medical Association Vol 104 No 2 March/April 2014
153
Evaluation of Wound Care and Health-Care Use Costs in Patients with Diabetic Foot Ulcers Treated with Negative Pressure Wound Therapy versus Advanced Moist Wound Therapy Vickie R. Driver, DPM, MS* Peter A. Blume, DPM† Background: We conducted a post-hoc retrospective analysis of patients enrolled in a randomized controlled trial to evaluate overall costs of negative pressure wound therapy (NPWT; V.A.C. Therapy; KCI USA, Inc, San Antonio, Texas) versus advanced moist wound therapy (AMWT) in treating grade 2 and 3 diabetic foot wounds during a 12-week therapy course. Methods: Data from two study arms (NPWT [n ¼ 169] or AMWT [n ¼ 166]) originating from Protocol VAC2001-08 were collected from patient records and used as the basis of the calculations performed in our cost analysis. Results: A total of 324 patient records (NPWT ¼ 162; AMWT ¼ 162) were analyzed. There was a median wound area reduction of 85.0% from baseline in patients treated with NPWT compared to a 61.8% reduction in those treated with AMWT. The total cost for all patients, regardless of closure, was $1,941,472.07 in the NPWT group compared to $2,196,315.86 in the AMWT group. In patients who achieved complete wound closure, the mean cost per patient in the NPWT group was $10,172 compared to $9,505 in the AMWT group; the median cost per 1 cm 2 of closure was $1,227 with NPWT and $1,695 with AMWT. In patients who did not achieve complete wound closure, the mean total wound care cost per patient in the NPWT group was $13,262, compared to $15,069 in the AMWT group. The median cost to close 1 cm 2 in wounds that didn’t heal using NPWT was $1,633, compared to $2,927 with AMWT. Conclusions: Our results show greater cost effectiveness with NPWT versus AMWT in recalcitrant wounds that didn’t close during a 12-week period, due to lower expenditures on procedures and use of health-care resources. (J Am Podiatr Med Assoc 104(2): 147153, 2014)
The rising global burden of diabetes and its complications have resulted in a massive drain on economic resources for society and individuals. In the United States alone, at least 23.6 million people are living with diabetes, 17.9 million of whom are diagnosed and 5.7 million not yet diagnosed.1 In 2010, the world prevalence of diabetes was approximately 6.4%, affecting 285 million adults; this number is expected to rise to 439 million adults by 2030.2 *Department of Surgery, Veterans Affairs New England Health Care Division, Providence, RI. †Department of Anesthesiology, Yale School of Medicine, New Haven, CT. Corresponding author: Vickie R. Driver, DPM, MS, FACFAS, Department of Surgery, VA New England Health Care Division, Department of Surgery, 830 Chalkstone Ave, Providence, RI 02908. (E-mail: [email protected])
The rise of diabetes will likely prompt a proportional increase in diabetic foot ulcers (DFUs), one of the most common complications of diabetes. In the United States, the annual incidence of DFUs is 1% to 4%, with a prevalence of about 4% to 10%, and a lifetime risk of occurrence between 15% and 25%.3-5 The total cost of treatment products, amputation, rehabilitation, and long-term care amounted to a staggering US $10.9 billion in 2006.4 The estimated average cost of treating a DFU in the United States ranges widely—from $4,595 per ulcer episode to nearly $28,000 (1995 US dollars) during the 2 years after diagnosis, and in excess of $30,000 during the ulcer’s life cycle.5-7 Approximately 85% of amputations are preceded by foot ulcers,8 with direct costs of performing a single amputation approaching $34,000.9 It is clear from ballooning
Journal of the American Podiatric Medical Association Vol 104 No 2 March/April 2014
147
health-care costs that treatment decisions must be considered on the basis of overall wound-care costs. The standard treatment for DFUs includes patient and wound assessment, moist wound care, frequent debridement, infection control, adequate off-loading, and restoring circulation.10-12 Based on suggested guidelines for the treatment of diabetic ulcers of the lower extremity, patients who fail to show a 40% reduction in ulcer size after 4 weeks of a given therapy should be reevaluated and other therapies should be considered.13 Historically, negative pressure wound therapy (NPWT) has largely been employed as a salvage therapy in diabetic wound treatment after other therapies have failed to close the ulcer. However, a growing body of evidence suggests that advanced technologies, such as NPWT, may be more efficacious when initiated early in the course of wound treatment. Reported benefits of earlier NPWT initiation include a reduction in the overall length of home-care stay for patients with surgical wounds or pressure ulcers,14 decreased mean time to 50% closure and reduced length of stay in long-term acute care wounds,8,15 reduction in total and variable costs for traumatic patients,16 and reduced total wound treatment costs.8 The American Recovery and Reinvestment Act emphasizes the importance of comparative effectiveness under the National Institutes of Health Challenge Grants in Health and Science Research. According to a 2007 Congressional Budget Office white paper, the term comparative effectiveness is defined as ‘‘generating evidence that compares treatments,’’ and includes comparative economics as well.17 Few comparative studies, however, have examined the direct costs as well as costs of therapeutic failure of advanced wound care modalities initiated early in the treatment of diabetic wounds. Whereas evidence-based medicine guidelines include well-defined scientific methods of conducting clinical efficacy studies, there is less agreement on how to conduct cost-effectiveness economic analyses. The standard methodology in a clinical trial typically calls for a finite period of time during which incidence of closure is measured. However, overall resource use should be an important consideration in determining true cost-effectiveness of a therapy. The objective of our study was to comparatively evaluate health-care costs, regardless of closure status, during a 12-week course of therapy. We conducted a post-hoc retrospective analysis of patients enrolled in a randomized controlled trial (RCT) to evaluate overall economic
148
costs of NPWT as delivered by vacuum assisted closure therapy (V.A.C. therapy, KCI USA, Inc, San Antonio, Texas) versus advanced moist wound therapy (AMWT) in treating Wagner’s grade stage 2 and 3 diabetic foot wounds.
Research Design and Methods We performed a post-hoc analysis of data obtained from diabetic foot ulcer patients who participated in an RCT to evaluate clinical efficacy of NPWT compared with AMWT. In the original study, a total of 342 patients were enrolled in a multicenter trial until ulcer closure or a maximum of 112 days.18 The patient population consisted of diabetic adults 18 years old or older who had a grade 2 or 3 calcaneal, dorsal, or plantar foot ulcer greater than 2 cm2 in area after debridement. Negative pressure wound therapy was delivered using the V.A.C. Therapy System. Advanced moist wound therapy dressings included use of alginates, hydrocolloids, foams, or hydrogels, according to Wound, Ostomy and Continence Nursing Society guidelines and institutional treatment protocols that follow standards of care for treating DFUs.19 Skin substitutes, cytokines, recombinant human platelet-derived growth factor, and similar therapies were prohibited in both treatment arms. Negative pressure wound therapy dressing changes were performed every 48 to 72 hours (minimum 3 times per week). Complete ulcer closure was defined as skin closure (100% epithelialization) without drainage or dressing requirements, either by delayed primary closure or healing by secondary intention. Patients were examined weekly for the first 4 weeks (day 28) and then every other week until day 112 or ulcer closure by any means. Economic Analysis Data from two different study arms (NPWT [n ¼ 169] or AMWT [n ¼ 166]) originating from Protocol VAC2001-08 were collected from patient records and used as the basis of the calculations performed in our cost analysis. Patients with missing data for hospitalizations during which a split- or full-thickness graft or flap was performed were excluded from analysis (n ¼ 7 for NPWT; n ¼ 4 for AMWT). Therefore, a total of 162 NPWT-treated and 162 AMWT-treated wounds were included in the final analysis. Costs were divided into wound therapy costs and nontherapy wound treatment costs. Wound therapy costs consisted of the cost of dressings or the
March/April 2014 Vol 104 No 2 Journal of the American Podiatric Medical Association
NPWT system, and labor during dressing changes. Nonwound therapy costs encompassed concomitant antibiotic therapy, acute inpatient services (including acute-care hospitalizations and woundrelated surgical procedures that were performed in an acute-care facility), extended care hospitalizations (ie, stays in skilled nursing facilities (SNFs), rehabilitation clinics, or hospice), and outpatient surgical procedures. Costs were calculated retrospectively based on the observed frequency that trial participants used health-care resources. Estimated hospital costs were derived from data from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample.20 Mean cost of physician services for lowerlimb amputation, debridement, and other woundrelated surgical procedures in acute-care and outpatient facilities were estimated using the Medicare Resource-Based Relative Value Scale 2007.21 The mean cost per inpatient day in extended-care facilities was estimated using the Medicare reimbursement rate for an SNF.22 Statistical Analysis For wound closure rate and rate of secondary amputation, treatment comparison was performed using Fisher’s exact test. For time to wound closure, a log-rank test was used for treatment comparison. For continuous parameters, such as total cost per patient, data were summarized using descriptive statistics (mean, standard deviation, median, and 95% two-sided confidence limits) by treatment group. All statistical tests were two-sided.
Results The final economic analysis was based on 162 NPWT-treated and 162 AMWT-treated wounds. Table 1 describes the patient demographics for both of these populations. Total Health-Care Resource Costs for All Patients The total cost for all patients, regardless of closure, was $1,941,472.07 (average per-patient cost: $11,984.40) in the NPWT group compared to $2,196,315.86 (average per-patient cost: $13,557.51) in the AMWT group (Table 2). The total wound treatment cost was $764,392.30 (average per-patient cost: $4,718.47) in the NPWT group compared to $374,599.14 (average per-patient cost: $2,312.34) in the AMWT group. The total nontherapy wound
Table 1. Patient Demographics Characteristics
NPWT (n ¼ 162)
AMWT (n ¼ 162)
Age (mean 6 SD) (years)
58 6 12
59 6 12
Sex (Male/Female)
136/26
120/42
Weight (mean 6 SD) (kg)
98.9 6 24.5
93.9 6 25.9
Current smoker (No.[%])
33 (20.4%)
32 (19.8%)
Type I diabetes (No.[%])
15 (9.3%)
14 (8.6%)
Type II diabetes (No.[%])
147 (90.7%)
148 (91.4%)
64 (39.5%)
68 (42.0%)
Wound stage (Wagner’s scale) Grade 2 (No.[%]) Grade 3 (No.[%]) Mean wound depth (cm)
75 (46.3%)
70 (43.2%)
1.0
1.0
Abbreviations: AMWT, advanced moist wound therapy; NPWT, negative pressure wound therapy.
treatment cost was $1,177,079.77 (average perpatient cost: $7,265.93) in the NPWT group compared to $1,821,716.73 (average per-patient cost: $11,245.17) in the AMWT group. Health-Care Resource Costs for Patients Who Achieved Wound Closure The removal of records with missing data resulted in a sample of 67 NPWT patients (41%) who achieved complete wound closure in the 112-day study compared to 44 AMWT patients (27%). The total aggregate wound care cost for NPWT patients was $681,549.42 (average per-patient cost: $10,172.38) compared to $418,230.24 (average perpatient cost: $9,505.23) for AMWT patients (Table 2). For NPWT patients, approximately 42% ($285,032.63) of the total health-care dollars were spent directly on NPWT while approximately 58% ($396,516.79) (Table 3) were spent on nontherapy wound treatment items. For AMWT patients, approximately 16% ($66,573.47) of the total healthcare dollars were spent on AMWT while approximately 84% ($351,656.77) (Table 3) were spent directly on nontherapy wound treatment items. The average nonwound treatment cost per NPWT patient was $10,716.67 compared to $13,525.26 per AMWT patient (Table 3). Health-Care Resource Costs for Patients Who Failed to Achieve Wound Closure Complete patient records were analyzed for 95 NPWT patients (59%) who failed to achieve complete wound closure during the 112-day study compared to 118 AMWT patients (73%). The total
Journal of the American Podiatric Medical Association Vol 104 No 2 March/April 2014
149
Table 2. Per-Patient Cost Based on Wound Closure Status Total Average Costs
Average Cost Per Patient
SD
Lower Confidence Limit
Upper Confidence Limit
NPWT (n ¼ 162)
$1,941,472.07
$11,984.40
$19,423.76
$8,970.69
$14,998.10
AMWT (n ¼ 162)
$2,196,315.86
$13,557.51
$21,923.21
$10,156.00
$16,959.01
All Patients
Patients Who Achieved Wound Closure NPWT (n ¼ 67)
$681,549.42
$10,172.38
$13,692.47
$6,832.52
$13,512.23
AMWT (n ¼ 44)
$418,230.24
$9,505.23
$20,289.99
$3,336.51
$15,673.95
Patients Who Did Not Achieve Wound Closure NPWT (n ¼ 95)
$1,259,922.65
$13,262.34
$22,595.76
$8,659.35
$17,865.34
AMWT (n ¼ 118)
$1,778,085.62
$15,068.52
$22,396.32
$10,985.34
$19,151.71
Abbreviations: AMWT, advanced moist wound therapy; NPWT, negative pressure wound therapy.
aggregate wound-care cost for these NPWT patients was $1,259,922.65 (average cost per patient: $13,262.34) compared to $1,778,085.62 (average cost per patient: $15,068.52) for these AMWT patients (Table 2). For NPWT patients, approximately 38% ($479,359.67) of the total health-care dollars were spent directly on NPWT while approximately 62% ($780,562.98) (Table 3) were spent on nontherapy wound treatment items (Table 4). For AMWT patients, approximately 17% ($308,025.67) of the total health-care dollars were spent directly on AMWT while approximately 83% ($1,470,059.95) (Table 3) were spent on nontherapy wound treatment items (Table 4). The average nonwound treatment cost per NPWT patient was $13,694.09 compared to $17,927.56 per AMWT patient (Table 3). Median Cost per cm2 Reduction There was a median wound area reduction of 85.0% from baseline in NPWT patients compared to a 61.8% reduction in AMWT patients. For those patients who achieved complete wound closure in the 112-day study, the median cost to close 1 cm2 of
the wound using NPWT was $1,226.54 compared to $1,695.45 using AMWT. For those patients who failed to achieve complete closure during the 112day active treatment phase, the median cost to close 1 cm2 of the wound using NPWT was $1,633.47 compared to $2,926.51 using AMWT. Regardless of closure status, the overall median cost to close 1 cm2 of the wound using NPWT was $1,460.42 compared to $2,566.17 using AMWT.
Discussion This study evaluated overall economic costs of NPWT versus AMWT for the treatment of grade 2 and 3 DFUs. More DFUs were closed completely with NPWT compared to AMWT with a higher average cost per patient in the NPWT group. However, more health-care dollars were spent on nontherapy wound treatment costs for AMWT patients. For those patients who failed to achieve complete closure, the total average wound-care cost was lower in the NPWT group compared to the AMWT group. Additionally, overall total costs for closed and nonclosed patients were also lower for the NPWT group.
Table 3. Nontherapy Wound Treatment Costs Average Cost per Patient for Non-Therapy Wound Treatment Cost
Total Non-Therapy Wound Treatment Cost
Percentage of Health-Care Dollars Spent Directly on Non-Therapy Wound Treatment Cost
Patients Who Achieved Wound Closure NPWT (n ¼ 67)
$10,716.67
$396,516.79
;58%
AMWT (n ¼ 44)
$13,525.26
$351,656.77
;84%
Patients Who Did Not Achieve Wound Closure NPWT (n ¼ 95)
$13,694.09
$780,562.98
;62%
AMWT (n ¼ 118)
$17,927.56
$1,470,059.95
;83%
Abbreviations: AMWT, advanced moist wound therapy; NPWT, negative pressure wound therapy.
150
March/April 2014 Vol 104 No 2 Journal of the American Podiatric Medical Association
Table 4. Health-Care Resource Cost for Nontherapy Wound Treatment for Patients Who Did Not Achieve Wound Closure
Health-Care Resource
Total Cost for NPWT Patients Who Did Not Achieve Wound Closure
Concomitant Antibiotic Therapy
$31,404.76
Total Cost for AMWT Patients Who Did Not Achieve Wound Closure $26,227.68
ACH – Amputation
$126,060.00
$441,210.00
ACH – Management of infection (without amputation)
$190,076.00
$360,144.00
ACH – All other reasons
$236,880.00
$485,604.00
ECH – SNF ECH – REHAB IF – Amputation IF – Debridements
$37,319.42
$47,177.38
$110,735.10
$15,038.10
$2,399.68
$7,798.96
$936.90
$2,342.25
IF – Other surgeries
$2,611.56
$1,119.24
IF – Bed-side visits
$17,926.00
$37,823.86
OF – Debridements
$23,301.96
$42,383.88
$911.60
$3,190.60
$780,562.98
$1,470,059.95
OF – Other surgeries Total
ACH: acute-care hospitalization; ECH: extended-care hospitalization; IF: inpatient facility; OF: outpatient facility.
Previous studies have included economic analyses based on the costs of treating wounds using NPWT compared to traditional wound-care dressings. For example, using clinical outcomes reported by Armstrong et al23 in their published RCT comparing NPWT and moist wound therapy (ie, alginates, hydrocolloids, foams, or hydrogels) for treating diabetic foot wounds, Apelqvist et al24 demonstrated cost savings using NPWT, including a reduction in average direct cost per patient and average total cost to achieve healing. Flack and colleagues25 used a Markov model to approximate the cost per amputation avoided and the cost per quality-adjusted life year of NPWT compared to traditional and advanced dressings. Results from this model showed an overall lower cost of care for NPWT patients compared to traditional therapies ($52,830 vs. $61,757 per person, respectively).25 Our findings are consistent with prior studies, showing higher overall total costs (wound and non–wound treatment related) for the AMWT group as compared to the NPWT group. Interestingly in our study, the average cost per patient for nontherapy wound treatment was higher in the AMWT group, regardless of closure, compared to the NPWT group. Overall, in the AMWT group, more health-care dollars were spent on nontherapy wound treatment (eg, antibiotics, hospitalizations, surgical procedures, and extendedcare hospitalization) costs than on actual wound treatment (ie, dressings and labor for dressing changes), which could indicate higher rates of complications and greater acute-care hospitaliza-
tions associated with this group (Table 4). A report by Rogers et al26 estimated that a major limb amputation costs approximately $70,434 (adjusting for health-care inflation in 2007) and that annual costs for diabetic amputations are about $11.7 billion. Indeed, in our study, there were more major and minor amputations in the AMWT group as compared to the NPWT group, which contributed greatly to nontherapy AMWT costs. Thus, this economic analysis shows that not only did AMWT patients heal slower, but the overall costs, including nontherapy costs, were greater in the AMWT group as compared to the NPWT group. The median cost to close 1 cm2 of a wound was lower for NPWT patients compared to AMWT patients, regardless of closure status, suggesting that NPWT may be more cost effective in terms of wound progression toward closure. Also, this costper-cm2 reduction over time may be of particular consideration to payers in cases where NPWT is used as a bridge to closure. The speed at which wounds undergo epithelialization is important with respect to cost and transition to surgical reconstruction with flaps and grafts. Our results are similar to a study by de Leon et al 27 who retrospectively examined the average daily wound volume reduction for postsurgical patients treated with NPWT compared to those treated with topical advanced moist healing therapies (control). The results showed that NPWT patients had a significantly higher average daily rate of volume reduction compared to the control group (5.02 6 13.36 versus 0.40 6 0.88 cm 3 /day; P ¼ 0.046), and more
Journal of the American Podiatric Medical Association Vol 104 No 2 March/April 2014
151
importantly, the cost-per-cm3 reduction was $11.90/ cm3 for NPWT patients versus $30.92/cm3 for the control group. Because the patients in the Blume RCT18 were high-risk patients with multiple comorbidities, achieving wound closure in a timely manner was critical to prevent further complications. Although there was a higher average cost per patient using NPWT for patients achieving closure, there were more DFUs that achieved closure and a significant reduction in median time to closure with NPWT. This type of high-risk patient may also benefit from early intervention with NPWT, which may affect treatment costs. Previous studies have demonstrated that early initiation of NPWT can reduce length of stay across care settings (acute care,16 long-term acute care,8,15 and home care14), which may translate into a potential reduction in costs. Furthermore, compared to late NPWT initiation, early NPWT initiation has also been associated with a reduction in overall wound treatment cost for diabetic patients in a long-term acute-care facility8 and for trauma patients in an acute care facility.16 Further studies are necessary to determine the impact of early intervention with NPWT on clinical outcomes and wound care costs for the treatment of DFUs. Although the primary endpoint for the Blume RCT18 and most clinical wound trials is complete wound closure, less than 50% of patients in that study18 achieved full closure. It is well reported that patients whose wounds do not close contribute to the majority of cost. Indeed, that is the case in our economic analysis. Because wound healing is a dynamic approach, especially in cases of nonhealing recalcitrant wounds, analysis based on various trajectories, versus all-or-none criteria, may be a more pragmatic approach to determining cost effectiveness.28 Thus, wound volume reduction, percent granulation, and wound contraction may be important trajectories that can be transitioned with respect to cost per cm2. The RCT data reported by Blume et al18 allowed us to evaluate cost effectiveness based on numerous trajectories. A weakness of the study was the lack of comprehensive data collection of multiple endpoints, which may have shown greater costs with respect to either group. A sensitivity analysis to examine the effects of unaccounted costs and varied assumptions with respect to our cost estimates was not performed. Newer techniques, such as the Arranz device,29 could have been used to include greater inclusion of depth and volume measurements in data gathering. In addition, wound
152
tracings may not be as accurate as computerassisted recordings of wound parameters, and debridements and interventions could have been tracked in a more succinct manner. In summary, our results show that NPWT is more cost effective than AMWT in recalcitrant wounds because of lower expenditures on resource use and procedures. Acknowledgment: The authors thank Jason Chan, of KCI, USA, and Bruce Stouch, of BCS Consulting, for performing the data analyses, and Karen Beach, Ricardo Martinez, and Julissa V. Ramos, KCI, for providing medical writing support. Financial Disclosure: None reported. Conflict of Interest: None reported.
References 1. CENTERS FOR DISEASE CONTROL AND PREVENTION: National Diabetes Fact Sheet, 2007. 1-1-2008. Atlanta, GA, U.S. Department of Health and Human Services, Centers for Disease Control and Prevention. 6-1-2009. 2. SHAW JE, SICREE RA, ZIMMET PZ: Global estimates of the prevalence of diabetes for 2010 and 2030. Diabetes Res Clin Pract 87: 4, 2010. 3. SINGH N, ARMSTRONG DG, LIPSKY BA: Preventing foot ulcers in patients with diabetes. JAMA 293: 217, 2005. 4. BOULTON A, BOWLING F: ‘‘Diabetic Foot Ulcers,’’ in Controversies in Treating Diabetes, edited by AI Vinik, D LeRoith, p 229, Humana Press, New York, NY, 2008. 5. SNYDER RJ, HANFT JR: Diabetic foot ulcers — effects on quality of life, costs, and mortality and the role of standard wound care and advanced-care therapies in healing: a review. Ostomy Wound Manage 55: 28, 2009. 6. RAMSEY SD, NEWTON K, BLOUGH D, ET AL: Incidence, outcomes, and cost of foot ulcers in patients with diabetes. Diabetes Care 22: 382, 1999. 7. HOLZER SE, CAMEROTA A, MARTENS L, ET AL: Costs and duration of care for lower extremity ulcers in patients with diabetes. Clin Ther 20: 169, 1998. 8. DRIVER VR, DE LEON JM: Health economic implications for wound care and limb preservation. J Manag Care Med 11: 13, 2008. 9. RAGNARSON TENNVALL G, APELQVIST J: Health-economic consequences of diabetic foot lesions. Clin Infect Dis 39: S132, 2004. 10. PHAM HT: Wound care in diabetic foot ulceration. Wounds 12: 82B, 2000. 11. SIBBALD RG, TORRANCE G, HUX M, ET AL: Cost-effectiveness of becaplermin for nonhealing neuropathic diabetic foot ulcers. Ostomy Wound Manage 49: 76, 2003. 12. CAVANAGH PR, LIPSKY BA, BRADBURY AW, ET AL: Treatment for diabetic foot ulcers. Lancet 366: 1725, 2005. 13. STEED DL, ATTINGER C, COLAIZZI T, ET AL: Guidelines for the treatment of diabetic ulcers. Wound Repair Regen 14: 680, 2006.
March/April 2014 Vol 104 No 2 Journal of the American Podiatric Medical Association
14. BAHARESTANI MM, HOULISTON-OTTO DB, BARNES S: Early versus late initiation of negative pressure wound therapy: examining the impact on home care length of stay. Ostomy Wound Manage 54: 48, 2008. 15. DE LEON JM, NAGEL M, FUDGE M, ET AL: Early use of negative pressure wound therapy in long-term acute care patients is associated with reduced length of stay. Abstract presented at the Third Congress of the World Union of Wound Healing Societies, June 4–8, 2008, Toronto, Ontario. PF225, 2008. 16. KAPLAN M, DALY D, STEMKOWSKI S: Early intervention of negative pressure wound therapy utilizing vacuum assisted closure in trauma patients: impact on hospital length of stay and cost. Adv Skin Wound Care 22: 128, 2009. 17. CONGRESSIONAL BUDGET OFFICE: Research on the comparative effectiveness of medical treatments. 1–48. 12-12007. Washington, DC, Congress of the United States, Congressional Budget Office. 18. BLUME PA, WALTERS J, PAYNE W, ET AL: Comparison of negative pressure wound therapy using vacuum-assisted closure with advanced moist wound therapy in the treatment of diabetic foot ulcers: a multicenter randomized controlled trial. Diabetes Care 31: 631, 2008. 19. [No author listed]. Guideline for management of wounds in patients with lower-extremity arterial disease. 6-12002. Glenview, IL, Wound Ostomy and Continence Nurses Society. WOCN clinical practice guideline series; no. 1. 20. RUSSO CA, STEINER C, SPECTOR W: Hospitalizations related to pressure ulcers among adults 18 years and older, 2006. HCUP Statistical Brief #64, 1–9. 12-1-2008, Agency for Healthcare Research and Quality, Rockville, MD, 127-2010. 21. WEST VIRGINIA BUREAU FOR MEDICAL SERVICES: 2007 National
22.
23.
24.
25.
26.
27.
28.
29.
Physician Fee Schedule Relative Value File. 1–52. 1-12007. West Virginia, West Virginia Department of Health and Human Services (DHHR). 10-18-2011. CENTERS FOR MEDICARE AND MEDICAID SERVICES (CMS) H: Medicare Program: Prospective payment system and consolidated billing for skilled nursing facilities — Update — Notice. Fed Regist 71: 43158, 2006. ARMSTRONG DG, LAVERY LA, Diabetic Foot Study Consortium: Negative pressure wound therapy after partial diabetic foot amputation: a multicentre, randomised controlled trial. Lancet 366: 1704, 2005. APELQVIST J, ARMSTRONG DG, LAVERY LA, ET AL: Resource utilization and economic costs of care based on a randomized trial of vacuum-assisted closure therapy in the treatment of diabetic foot wounds. Am J Surg 195: 782, 2008. FLACK S, APELQVIST J, KEITH M, ET AL: An economic evaluation of VAC therapy compared with wound dressings in the treatment of diabetic foot ulcers. J Wound Care 17: 71, 2008. ROGERS LC, LAVERY LA, ARMSTRONG DG: The right to bear legs–an amendment to healthcare: how preventing amputations can save billions for the US Health-care System. JAPMA 98: 166, 2008. DE LEON JM, BARNES S, NAGEL M, ET AL: Cost-effectiveness of negative pressure wound therapy for postsurgical patients in long-term acute care. Adv Skin Wound Care 22: 122, 2009. LAVERY LA, BARNES SA, KEITH MS, ET AL: Prediction of healing for post-operative diabetic foot wounds based on early wound area progression. Diabetes Care 31: 26, 2008. KIESER DC, HAMMOND C: Leading wound care technology: The ARANZ medical silhouette. Adv Skin Wound Care 24: 68, 2011.
Journal of the American Podiatric Medical Association Vol 104 No 2 March/April 2014
153
